The authors are grateful to Andr&#233;e Nienkerk, Dennis Peyron, and Sebastian Skj&#246;ld for supervising the training sessions and several tests; to the subjects participating; to Tim Crosfield for language revision; and to the economic support from The Swedish School of Sport and Health Sciences.

<ol>
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The authors declare that they have no competing financial interests.

In this study, a number of techniques have been used to investigate the effects of short-term progressive resistance training on elderly subjects&#39; muscle function/morphology, aerobic capacity, and glucose tolerance. The main finding was that, compared to a control group, many improvements occurred in muscle aerobic capacity, glucose tolerance, strength, power, and muscle quality (i.e., protein involved in cell signaling and muscle fiber composition). An increase was, for example, seen for: static, eccentric, and concentric maximal knee extension strength (8-12%); the training loads (19-72%), maximal rate of force development (RFD) at the initial 0-30 ms (52%); several mitochondrial proteins (30-90%); the proteins Akt and mTor, involved in the muscle protein synthesis (both 69%).
Elderly people can have difficulties with sustained health during such a project. One must be aware of the risk for various injuries due to testing and training among untrained elderly. One person in the RET group at the end of the training period had a relapse of former back problems. However, no injury or discomfort occurring during the training project remained for a prolonged time after the end of the investigation among the old participants. Modifications can sometimes be done regarding when, how much, and how intensively the training should be done. Regarding the strength training regime, it is preferable that the coach registers the load obtained for each training exercise and subject at each training session so that a proper progression can be followed throughout the period. During strength measurement with the isokinetic dynamometer, it is important to avoid any error in the measurement procedure so that the elderly subjects do not miss their maximal performance during their trials. For this reason, it is of value to have warm-ups. Use 8-10 min of ergometer cycling at submaximal levels prior to the strength measurements, followed by initial trials as a familiarization procedure in the dynamometer for knee strength recordings. Furthermore, it is a good idea to perform four recordings during the recordings of each type of muscle strength contraction; highest value found can be selected. It is also of great value to examine the modification of strength assessment in relation to velocity when achieving the test parameter power. In particular, increased power is an important factor for improved health among elderly people. Regarding the biopsy, the subjects are told to avoid aspirin or other anti-coagulation agents before and after the biopsy. Concerning the determination of muscle fiber area in duplicate biopsies from the same leg for type I, type 2A, and type 2B, the reported errors are about 10, 15, and 15%, respectively29. This must be considered when evaluating such analysis from a muscle biopsy.
The limitations include concerns regarding Western blot; the method gives no information about protein localization and is highly dependent upon the specificity and quality of the antibody (a major issue). The multi-step analysis increases the risk of errors and aggravates troubleshooting. However, there are several advantages of Western blotting: it is relatively cheap and fast; it gives a high data output in relation to the amount of tissue required; one acquires information about protein expression and protein size; and finally, the coefficient of variation is generally less than 5%. The period of strength training was only eight weeks, and no later follow-up measures have been done with these elderly people. The glucose tolerance tests based on drinking glucose solutions (OGTT) are not considered as appropriate as when the glucose is injected directly into the blood. However, the method used with OGTT is cheaper, easier to administrate, and is widely used in the clinic. Regarding the strength measures with the isokinetic dynamometer, only muscles contributing to knee extensor strength were studied, and not the other major body muscle groups.
In addition to improved strength, resistance training also improved glucose tolerance and muscle oxidative capacity. There were large increases in the training load for each exercise performed (19-72%), demonstrating that resistance training afforded substantial improvements in overall strength. Measurements with an isokinetic dynamometer provided more detailed information on knee extensor function. The torque during static, eccentric, and concentric contraction increased by 8-12%. Furthermore, resistance training resulted in a large increase (52%) in the rate of force development (RFD) during the initial phase of contraction (0-30 ms), whereas it was unchanged between 0-200 ms. The training protocol was well tolerated and, contrary to our expectations, there were no dropouts in the RET group.
Resistance training resulted in hypertrophy, measured as increases in FFM, thigh circumference, and thigh cross-sectional area. The CSA of the different muscle fiber types was not changed significantly after the RET, but there was a shift in fiber type composition from type IIx to type IIa. Since type IIa fibers are larger than type IIx fibers, this contributed to the increased muscle mass. In the RET group, this indicates that protein synthesis was enhanced. The underlying molecular signaling pathway for protein synthesis involves the activation of Akt and mTOR. Elderly people have less mTOR protein in muscle30, which may restrict protein synthesis. An interesting novel finding is the increased protein levels of mTOR and Akt in the RET group. The observed increase in mTOR here may counteract any possible anabolic resistance and contribute to increased protein synthesis.
VO2max or, more correctly, VO2peak, is often assessed as the maximal VO2 measured during a test where the work rate is increased step-wise until exhaustion. However, in aged, frail subjects, it is problematic to use exhaustive exercise tests. One problem is that it is not uncommon that the elderly have a latent cardiovascular disease which, during an exhaustive exercise test, leads to an increased risk of heart attack. Another, more technical, problem is that reduced muscle strength rather than a cardiorespiratory limitation may limit the work rate during incremental exercise. Interpretation of data will, under these conditions, be more complicated. An alternative method, used in this study, is to measure HR and RER at a fixed work rates pre- and post-intervention. The results showed that the HR tended to decrease in the RET but increase in the CON group. This suggests that strength training improves VO2max and endurance exercise capacity. These findings match with the results in some9,31, but not all32, previous studies. Furthermore, several findings in this study show that muscle aerobic capacity improves (i.e., with changes to a more oxidative fiber type composition and increases in a number of mitochondrial proteins). Although it is well known that endurance exercise improves muscle aerobic capacity in the elderly, studies of strength training give a more contradictory view8,9,10,33. Differences in initial training status and training programs may explain the different outcome in different studies. The present results showing a robust increase in several mitochondrial proteins after only eight weeks of training (previous intervention periods were &#62;12 weeks) demonstrate that resistance training can be an effective strategy to improve muscle oxidative capacity.
Despite the short intervention, improved glucose tolerance was observed in the RET group, as shown by the reduction in AUCglucose and GLU120 min. Although obesity and physical inactivity are factors associated with an increased risk of insulin resistance and type 2 diabetes, the molecular mechanisms remain obscure. The altered body composition with increased muscle mass will likely contribute to the improved glucose tolerance in the RET group. Furthermore, it has been hypothesized that insulin resistance is linked to a sedentary lifestyle, with excess lipid supply leading to lipotoxicity, mitochondrial dysfunction, and oxidative stress3. The present study shows that resistance training results in a robust increase in mitochondrial oxidative proteins. We hypothesize that the increased muscle oxidative capacity is one factor explaining the increased glucose tolerance.
Investigations with longer follow-ups are desirable for showing whether and for how long the health effects persist in terms of improved muscle aerobic capacity, strength, power, glucose, and lipid values. Also, it is of value to determine the sufficient dose of regular strength training among elderly people. Future applications are also strength measurements in major muscle groups other than the knee extensors. One can also make several other detailed analyses within the muscle cells regarding various proteins and functions within and without the mitochondria.
It is important to have one day in between each test day with no vigorous or prolonged physical activity, the same day or the day before the tests, since this can influence the outcome of the assessments. Examples of critical steps regarding histochemistry and ATPase staining for fiber type composition include ensuring that the piece from the biopsy is treated with isopentane shortly after the biopsy is taken and that the isopentane is at the right temperature so that the biopsy will not be destroyed. Furthermore, the biopsy piece must be &#34;stretched or installed,&#34; so that the fibers are pointing in the same direction, prior to treatment with isopentane. During staining, the pH and temperature of the laboratory must be optimal (and this is difficult to predict). However, this is the only way to ensure the fiber types and fiber area. In addition, the method is quick, showing results within two days, and the technique is relatively inexpensive, with no costly chemicals or devices needed.
The distinct improvement in muscle aerobic capacity after strength training challenges the view that endurance exercise is the preferred mode of exercise. However, in elderly people with low VO2max and muscle strength, endurance exercise must be performed at low intensities. One of the main stimuli of mitochondrial biogenesis is muscle energetic stress34. Strength training induces a major local energetic stress, whereas this is less prominent during low-intensity endurance exercise. We hypothesize that in elderly people, strength training is more efficient than endurance exercise to enhance muscle aerobic capacity. Furthermore, considering the improvements in a number of health-related parameters and the high compliance, strength training may be recommended for elderly people.

Aging is associated with a loss of muscle mass (sarcopenia), strength, and power. Reduced strength, and probably even more importantly, power, results in immobility, an increased risk of injury, and a reduced quality of life. Resistance training is a well-known strategy to counteract sarcopenia and deteriorating muscle function. A rough estimate of muscle strength can be obtained from the load or number of achieved repetitions. However, this study obtained more detailed and accurate information on muscle function using an isokinetic dynamometer to gather information on the torque during isometric, concentric and eccentric contraction, as well as on the kinetics of force development.
Aerobic capacity, both at the whole-body level (VO2max) and in skeletal muscle, is reduced in elderly people. The decline in heart rate with age explains a large part of the decrease in VO2max1, but reduced muscle oxidative capacity, largely related to reduced physical activity2, does contribute. Impaired mitochondrial function may also be involved in the development of sarcopenia and insulin resistance3. The muscle aerobic capacity was assessed in muscle biopsies through biochemical analyses of the contents of mitochondrial enzymes and protein complexes located both in the matrix (i.e., citrate synthase) and the inner mitochondrial membrane. In addition, histochemical techniques were used to measure the effect of resistance training on muscle morphology (i.e., fiber type composition, fiber cross-sectional area, and capillary density). An alternative method to assess muscle aerobic capacity would be to use magnetic resonance spectroscopy to measure the rate of creatine phosphate resynthesis after exercise-induced depletion4. This method provides an estimate of the in vivo muscle aerobic capacity but cannot discriminate between mitochondrial dysfunction and circulatory disorders. Furthermore, the high costs of equipment limit the use of this technique in most laboratories. Aerobic capacity (VO2max and mitochondrial density) can be improved by endurance exercise in both young and old people5,6. However, the effect of resistance training on these parameters has been less investigated, especially in elderly subjects, and the results are conflicting7,8,9,10.
Type 2 diabetes is a widespread disease in the elderly population. Physical inactivity and obesity are major lifestyle-related factors explaining the increased incidence of type 2 diabetes. Low-intensity aerobic exercise is often recommended to subjects with reduced glucose tolerance. However, it is unclear how strength training in the elderly affects glucose tolerance/insulin sensitivity11,12. The most accurate way to measure insulin sensitivity is to use the glucose clamp technique, where the blood glucose is maintained constant by glucose infusion during conditions of elevated insulin13. The disadvantages with this technique are that it is time consuming and invasive (arterial catheterization) and requires special laboratory facilities. In this study, the oral glucose tolerance test, which is common in healthcare units, was used. This method is suitable when several subjects are to be investigated for a limited period of time.
The testing and timeline of the experimental procedure can be summarized as follows. Use three separate days for testing before and after an eight-week period, with the same arrangement and approximate time schedules (&#8805;24 h between each day, Figure 1). On the first test day, measure: anthropometric data, such as height, body mass, fat-free mass (FFM), and upper leg circumference (i.e., 15 cm above the apex patellae in a relaxed supine position); submaximal cycling ability; and knee muscle strength, as described in steps 4 and 5. Take a muscle biopsy from the thigh on the second test day. For further descriptions, see step 6.1. Test oral glucose tolerance (OGTT) on the last testing day. For further descriptions, see step 7.1. Ask all participants to avoid vigorous physical activity for 24 h and to fast overnight prior to each test day. However, ask them to avoid strenuous physical activity for 48 h before the OGTT test day. Ask them to follow their normal everyday physical activity and diet habits. Note that pre- and post-intervention, both groups&#39; self-reported food intake and type of foods were unchanged.
<img alt="Figure 1" class="xfigimg" src="/files/ftp_upload/55518/55518fig1.jpg" /> 
Figure 1: Experimental protocol. Schematic diagram. The timing between the three pre- and post-tests was similar for each subject and was at least 24 h. Further details are given in the text. This figure has been modified from Frank et al. Scand. J. Med. Sci. Sports. 2016: 26, 764-73.28 <a href="https://cloudflare-jove-com.remotexs.ntu.edu.sg/files/ftp_upload/55518/55518fig1large.jpg" target="_blank">Please click here to view a larger version of this figure.</a>
This study sought to investigate the effect of short-term resistance training in elderly people on muscle oxidative capacity and glucose tolerance. The second aim was to examine the effect on strength, power, and muscle qualitative improvements (i.e., proteins involved in cell signaling and muscle fiber type composition).

<table><tbody><tr><td>&lt;strong&gt;Western blot&lt;/strong&gt;</td><td></td><td></td><td></td></tr><tr><td>Pierce 660 nm Protein Assay Kit</td><td>Thermo Scientific, Rockford, IL, USA</td><td>22662</td><td></td></tr><tr><td>SuperSignal West Femto Maximum Sensitivity Substrate&amp;nbsp;</td><td>Thermo Scientific</td><td>34096</td><td></td></tr><tr><td>Halt Protease Inhibitor Cocktail (100x)</td><td>Thermo Scientific</td><td>78429</td><td></td></tr><tr><td>Restore PLUS Western Blot Stripping Buffer</td><td>Thermo Scientific</td><td>46430</td><td></td></tr><tr><td>Pierce Reversible Protein Stain Kit for PVDF Membranes</td><td>Thermo Scientific</td><td>24585</td><td></td></tr><tr><td>10 st - 4&amp;ndash;20% Criterion TGX Gel, 18 well, 30 &amp;micro;L</td><td>Bio-Rad Laboratories, Richmond, CA, USA</td><td>567-1094</td><td></td></tr><tr><td>Immun-Blot PVDF Membrane&amp;nbsp;</td><td>Bio-Rad</td><td>162-0177</td><td></td></tr><tr><td>Precision Plus Protein Dual Color Standards&amp;nbsp;</td><td>Bio-Rad</td><td>161-0374</td><td></td></tr><tr><td>2x Laemmli Sample Buffer</td><td>Bio-Rad</td><td>161-0737</td><td></td></tr><tr><td>10x Tris/Glycine</td><td>Bio-Rad</td><td>161-0771</td><td></td></tr><tr><td>2-Mercaptoethanol</td><td>Bio-Rad</td><td>161-0710</td><td></td></tr><tr><td>Tween 20</td><td>Bio-Rad</td><td>P1379-250ML</td><td></td></tr><tr><td>Band analysis with Quantity One version 4.6.3.software</td><td>Bio-Rad</td><td></td><td></td></tr><tr><td>1% phosphatase inhibitor coctail</td><td>Sigma-Aldrich, Saint Louis, Missouri, USA</td><td></td><td></td></tr><tr><td>&lt;strong&gt;Antibodies&lt;/strong&gt;</td><td></td><td></td><td></td></tr><tr><td>mTOR (1:1,000)</td><td>Cell Signaling, Danvers, Massachusetts, USA</td><td>2983</td><td></td></tr><tr><td>Akt (1:1,000)</td><td>Cell Signaling, Danvers</td><td>9272</td><td></td></tr><tr><td>Secondary anti-rabbit and anti-mouse HRP-linked (1:10,000)</td><td>Cell Signaling, Danvers</td><td></td><td></td></tr><tr><td>Citrate synthase (CS) (1:1,000)</td><td>Gene tex, San Antonio, California, USA</td><td></td><td></td></tr><tr><td>OXPHOS (1:1,000)</td><td>Abcam, Cambridge, UK</td><td></td><td></td></tr><tr><td>&lt;strong&gt;Equipment - Analysis of muscle samples&lt;/strong&gt;</td><td></td><td></td><td></td></tr><tr><td>Bullet Blender 1.5 for homogenizing</td><td>Next Advance, New York, USA</td><td></td><td></td></tr><tr><td>Plate reader</td><td>Tecan infinite F200 pro, M&amp;auml;nnedorf, Switzerland</td><td></td><td></td></tr><tr><td>&lt;strong&gt;Histochemistry&lt;/strong&gt;</td><td></td><td></td><td></td></tr><tr><td>Mayer hematoxylin</td><td>HistoLab, V&amp;auml;stra Fr&amp;ouml;lunda, Sweden&amp;nbsp;</td><td>1820</td><td></td></tr><tr><td>Oil Red o</td><td>Sigma-Aldrich, Saint Louis, Missouri, USA</td><td>00625-25y</td><td></td></tr><tr><td>NaCl</td><td>Sigma-Aldrich</td><td>793566-2.5 kg</td><td></td></tr><tr><td>Cobalt Chloride</td><td>Sigma-Aldrich</td><td>60818-50G</td><td></td></tr><tr><td>Amylase</td><td>Sigma-Aldrich</td><td>A6255-25MG</td><td></td></tr><tr><td>ATP</td><td>Sigma-Aldrich</td><td>A2383-5G</td><td></td></tr><tr><td>Glycine</td><td>VWR-chemicals / VWR-international, Sp&amp;aring;nga, Sweden</td><td>101196X</td><td></td></tr><tr><td>Calcium Chloride</td><td>VWR-chemicals / VWR-international</td><td>22328.262</td><td></td></tr><tr><td>Iso-pentane</td><td>VWR-chemicals / VWR-international</td><td>24872.298</td><td></td></tr><tr><td>Etanol 96%</td><td>VWR-chemicals / VWR-international</td><td>20905.296</td><td></td></tr><tr><td>NaOH</td><td>MERCK, Stockholm, Sweden</td><td>1.06498.1000</td><td></td></tr><tr><td>Na acetate</td><td>MERCK</td><td>1.06268.1000</td><td></td></tr><tr><td>KCl</td><td>MERCK</td><td>1.04936.1000</td><td></td></tr><tr><td>Ammonium Sulphide</td><td>MERCK</td><td>U1507042828</td><td></td></tr><tr><td>Acetic acid 100%</td><td>MERCK</td><td>1.00063.2511</td><td></td></tr><tr><td>Schiffs&amp;acute; Reagent</td><td>MERCK</td><td>1.09033.0500</td><td></td></tr><tr><td>Periodic acid</td><td>MERCK</td><td>1.00524.0025</td><td></td></tr><tr><td>Chloroform</td><td>MERCK</td><td>1.02445.1000</td><td></td></tr><tr><td>pH-meter LANGE</td><td>HACH LANGE GMBH, Dusseldorf, Germany</td><td></td><td></td></tr><tr><td>Light microscope</td><td>Olympus BH-2, Olympus, Tokyo, Japan</td><td></td><td></td></tr><tr><td>Cryostat&amp;nbsp; Leica CM1950</td><td>Leica Microsystems, Wetzlar, Germany</td><td></td><td></td></tr><tr><td>Leica software Leica Qwin V3</td><td>Leica Microsystems</td><td></td><td></td></tr><tr><td>Gel Doc 2000 - Bio-Rad, camera setup</td><td>Bio-Rad Laboratories AB, Solna, Sweden&amp;nbsp;</td><td></td><td></td></tr><tr><td>Software program Quantift One - 4.6 (version 4.6.3; Bio Rad)</td><td>Bio-Rad Laboratories AB, Solna, Sweden&amp;nbsp;</td><td></td><td></td></tr><tr><td>&lt;strong&gt;Oral glucos tolerance test, OGTT&lt;/strong&gt;</td><td></td><td></td><td></td></tr><tr><td>Glukos APL 75 g</td><td>APL, Stockholm, Sweden</td><td>323,188</td><td></td></tr><tr><td>Automated analyser Biosen 5140</td><td>EKF Diagnostics, Barleben, Germany</td><td></td><td></td></tr><tr><td>Insulin and C-peptide in plasma kit ELISA</td><td>Mercodia AB, Uppsala Sweden</td><td>10-1132-01, 10-1134-01</td><td></td></tr><tr><td>Plate reader</td><td>Tecan infinite F200 pro, M&amp;auml;nnedorf, Switzerland</td><td></td><td></td></tr><tr><td>&lt;strong&gt;Further equipment&lt;/strong&gt;</td><td></td><td></td><td></td></tr><tr><td>Measures of fat-free mass</td><td>FFM-Tanita T5896, Tanita, Tokyo, Japan</td><td></td><td></td></tr><tr><td>Strength training equipment for all training exercises</td><td>Cybex International Inc., Medway, Massachusetts, USA&amp;nbsp;</td><td></td><td></td></tr><tr><td>Cycle ergometer&amp;nbsp;</td><td>Monark Ergometer 893E, Monark Exercises, Varberg, Sweden&amp;nbsp;</td><td></td><td></td></tr><tr><td>Heart rate monitor RS800, Polar</td><td>Polar Electro OY, Kampele, Finland</td><td></td><td></td></tr><tr><td>Oxycin-Pro - automatic ergo-spirometric device</td><td>Erich Jaeger GmbH, Hoechberg, Germany</td><td></td><td></td></tr><tr><td>Isokinetic dynamometer, Isomed 2000, knee muscle strength</td><td>D&amp;amp;R Ferstl GmbH, Henau, Germany</td><td></td><td></td></tr><tr><td>CED 1401 data acquisition system and Signal software</td><td>Cambridge Electronic Design, Cambridge, UK</td><td></td><td></td></tr><tr><td>Software for muscle strength analysis, Spike 2, version 7</td><td>Signal Hound, LA Center, WA, USA</td><td></td><td></td></tr><tr><td>Statistica software for statistical analyses</td><td>Statistica, Stat soft. inc, Tulsa, Oklahoma, USA</td><td></td><td></td></tr><tr><td>&lt;strong&gt;Muscle biopsy equipment&lt;/strong&gt;</td><td></td><td></td><td></td></tr><tr><td>Weil Blakesley conchotome</td><td>Wisex, M&amp;ouml;lndal, Sweden</td><td></td><td></td></tr><tr><td>Local anesthesia&amp;nbsp;</td><td>Carbocain, 20 mL, 20 mg/mL; Astra Zeneca, S&amp;ouml;dert&amp;auml;lje, Sweden</td><td>169,367</td><td></td></tr><tr><td>Surgical Blade</td><td>Feather Safety Razor CO, LTD, Osaka, Japan&amp;nbsp;</td><td>11048030</td><td></td></tr></tbody></table>

improving strength, power, muscle aerobic capacity, and glucose tolerance through short-term progressive strength training among elderly people

This protocol describes the simultaneous use of a broad span of methods to examine muscle aerobic capacity, glucose tolerance, strength, and power in elderly people performing short-term resistance training (RET). Supervised progressive resistance training for 1 h three times a week over 8 weeks was performed by RET participants (71&#177;1 years, range 65-80). Compared to a control group without training, the RET showed improvements on the measures used to indicate strength, power, glucose tolerance, and several parameters of muscle aerobic capacity. Strength training was performed in a gym with only robust fitness equipment. An isokinetic dynamometer for knee extensor strength permitted the measurement of concentric, eccentric, and static strength, which increased for the RET group (8-12% post- versus pre-test). The power (rate of force development, RFD) at the initial 0-30 ms also showed an increase for the RET group (52%). A glucose tolerance test with frequent blood glucose measurements showed improvements only for the RET group in terms of blood glucose values after 2 h (14%) and the area under the curve (21%). The blood lipid profile also improved (8%). From muscle biopsy samples prepared using histochemistry, the amount of fiber type IIa increased, and a trend towards a decrease in IIx in the RET group reflected a change to a more oxidative profile in terms of fiber composition. Western blot (to determine the protein content related to the signaling for muscle protein synthesis) showed a rise of 69% in both Akt and mTOR in the RET group; this also showed an increase in mitochondrial proteins for OXPHOS complex II and citrate synthase (both ~30%) and for complex IV (90%), in only the RET group. We demonstrate that this type of progressive resistance training offers various improvements (e.g., strength, power, aerobic capacity, glucose tolerance, and plasma lipid profile).

Material
In the study, 21 relatively healthy women and men, 65-80 years old and with BMI values between 20 and 30 kg&#183;m-2 participated and were randomized into two groups. Individuals in both groups had relatively low physical activity levels (i.e., a moderate everyday physical activity level and no regular exercise training). One group (n=12, 6 women and 6 men) performed RET under a trainer for 1 h three times a week for eight weeks, and the other group served as controls (n=10, 5 women and 5 men). The RET and CON groups were balanced in terms of age, sex, and BMI (Table 1). More subjects were recruited to the RET group to make up for dropouts; more were anticipated in the RET group over the CON group.
<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr>
			<td colspan="2"></td>
			<td colspan="2">RET (n=12)</td>
			<td colspan="2">CON (n=9)</td>
		</tr>
		<tr>
			<td colspan="2"></td>
			<td>Pre</td>
			<td>Post</td>
			<td>Pre</td>
			<td>Post</td>
		</tr>
		<tr>
			<td colspan="2">Age (years)</td>
			<td colspan="2">71.4&#177;1.1</td>
			<td colspan="2">72.0&#177;1.4</td>
		</tr>
		<tr>
			<td colspan="2">BMI</td>
			<td>24.6&#177;0.8</td>
			<td>24.9&#177;0.8</td>
			<td>23.2&#177;0.8</td>
			<td>23.2&#177;0.8</td>
		</tr>
		<tr>
			<td colspan="2">Weight (kg)</td>
			<td>70.4&#177;2.9</td>
			<td>71.1&#177;2.8</td>
			<td>67.4&#177;3.9</td>
			<td>67.6&#177;3.9</td>
		</tr>
		<tr>
			<td colspan="2">FFM (kg)</td>
			<td>51.0&#177;2.3</td>
			<td>52.4&#177;2.1**</td>
			<td>47.6&#177;4.1</td>
			<td>48.6&#177;4.3</td>
		</tr>
		<tr>
			<td colspan="2">Thigh Cross-sectional area (cm&#178;)</td>
			<td>188.9&#177;9</td>
			<td>200&#177;8***&#8224;</td>
			<td>155&#177;12</td>
			<td>154&#177;11</td>
		</tr>
		<tr>
			<td rowspan="3">Fiber Cross-sectional area (cm&#178;)</td>
			<td>Type I</td>
			<td>5452&#177;393</td>
			<td>5567&#177;362</td>
			<td>4889&#177;323</td>
			<td>4807&#177;354</td>
		</tr>
		<tr>
			<td>Type IIa</td>
			<td>4230&#177;610#</td>
			<td>4484&#177;434#</td>
			<td>4114&#177;535#</td>
			<td>3971&#177;494#</td>
		</tr>
		<tr>
			<td>Type Iix</td>
			<td>3678&#177;634#</td>
			<td>3554&#177;552#</td>
			<td>3392&#177;889#</td>
			<td>2913&#177;427#</td>
		</tr>
	</tbody>
</table>
Table 1: Participants&#39; Characteristics. RET, resistance exercise training; CON, control; BMI, body mass index; FFM, fat-free mass. Values are from 12 (RET) and 9 (CON) subjects, except for fiber cross-sectional area (RET, n=10; CON, n=7), and are presented as the mean &#177; SEM. **, p&#60;0.01 versus pre; ***, p&#60;0.001 versus pre; &#8224;, p&#60;0.05 versus CON post; &#8224;&#8224;&#8224;, p&#60;0.001 versus CON post; #, p&#60;0.05 versus type I. This table has been modified from Frank et al. Scand. J. Med. Sci. Sports. 2016:26, 764-73.28
Beta-blocker users and those with coronary artery disease and severe neurological or joint problems were excluded. At baseline, some subjects had: high blood pressure (2 in each group); depression (1 in each group); and medication for dyslipidemia (2 in RET and 1 in CON), hypothyreosis (1 in RET), an early stage of Parkinson&#39;s disease (RET). Medication was taken sporadically for asthma (1 in RET) and rheumatic problems (1 in CON). One person had a pacemaker (CON).
One RET subject interrupted the training after 6 weeks due to back pain but was still included in the study. One initial CON subject was excluded due to knee problems during the pre-test of strength. Those with asthma and the pacemaker were excluded from the cycle test.
The subjects gave their written consent after have been informed of possible discomfort and risks in the test and training sessions.
Data are presented as means &#177; SEM. Differences between RET and CON were tested for statistical significance with two-way repeated measures ANOVA using a statistical program. When significant main effects or interactions were shown, differences were located with post-hoc analyses (Fisher LSD). Statistical significance was accepted at p&#60;0.05.
The trainees (RET) showed, compared to the CON group, improvement on the measurements taken in strength, power, glucose tolerance, and several parameters of muscle aerobic capacity. Using an isokinetic dynamometer for knee extensor strength permitted the measurement of concentric, eccentric, and static strength (which all increased by 8-12% for RET post- versus pre-test, Figure 2A). The dynamometer also showed the rate of force development (RFD), with an increase of 52% (at the initial 0-30 ms) for the RET group (Figure 2B). For the CON group, concentric strength was reduced during the intervention period. The training load for RET improved by 19-72% for the training exercises performed.
<img alt="Figure 2" class="xfigimg" src="/files/ftp_upload/55518/55518fig2.jpg" /> 
Figure 2: Strength measurement results. The effect of resistance exercise training (RET) or control period (CON) on (A) static (STAT), eccentric (ECC), and concentric (CONC) torque and (B) rate of force development (RFD) during 0-30 ms and 0-200 ms of static knee extension. Values are from 12 (RET) and 9 (CON) subjects and are presented as percent change relative to basal values (mean &#177; SEM). *, p&#60;0.05 versus pre; **, p&#60;0.01 versus pre; ***, p&#60;0.001 versus pre. This figure has been modified from Frank et al. Scand. J. Med. Sci. Sports. 2016: 26, 764-73.28 <a href="https://cloudflare-jove-com.remotexs.ntu.edu.sg/files/ftp_upload/55518/55518fig2large.jpg" target="_blank">Please click here to view a larger version of this figure.</a>
From the muscle biopsy samples, histochemistry indicated that the amount of fiber type IIa increased, and there was a trend to a decrease in IIx for the RET group. Thus, the RET group showed a change to a more oxidative profile in terms of fiber composition (Figure 3). Note that reliable cross-sections could not be obtained from the biopsies of four subjects (two from each group), and the results from these subjects were excluded.
<img alt="Figure 3" class="xfigimg" src="/files/ftp_upload/55518/55518fig3.jpg" /> 
Figure 3: Muscle fiber type composition results. The effect of resistance exercise training (A, RET) or control period (B, CON). Values are from 10 (RET) and 7 (CON) subjects and are presented as the mean &#177; SEM. (*), p=0.068 versus pre; **, p&#60;0.01 versus pre; &#8224;, p&#60;0.05 versus CON post. This figure has been modified from Frank et al. Scand. J. Med. Sci. Sports. 2016: 26, 764-73.28 <a href="https://cloudflare-jove-com.remotexs.ntu.edu.sg/files/ftp_upload/55518/55518fig3large.jpg" target="_blank">Please click here to view a larger version of this figure.</a>
Furthermore, Western blot analyses for determining protein content related to the signaling of muscle protein synthesis showed a rise of 69% for both Akt and mTOR (mammalian target of rapamycin) among the RET group (Figure 4A and Figure 5). Western blot analyses also proved, among mitochondrial proteins, an increase of about 30% both for OXPHOS complex II and citrate synthase, and of 90% for complex IV in the RET group (Figure 4B and Figure 5). The primary antibodies used were mTOR, Akt, and OXPHOS. Anti-rabbit or anti-mouse HRP was used as THE secondary antibody. The protein bands for OXPHOS complex I were not clearly visible, and these data were discarded.
<img alt="Figure 4" class="xfigimg" src="/files/ftp_upload/55518/55518fig4.jpg" /> 
Figure 4: Muscle protein results. The effect of resistance exercise training (RET) or a control period (CON) on changes in muscle contents of Akt and mTOR proteins (A) and mitochondrial proteins (B). Akt, protein kinase B; mTOR, mammalian target of rapamycin; CS, citrate synthase. Values are the means &#177; SEM from 11 (RET) and 9 (CON) subjects. *, p&#60;0.05; **, p&#60;0.01; ***, p&#60;0.001 versus basal. &#8224;, p&#60;0.05; &#8224;&#8224;, p&#60;0.01; &#8224;&#8224;&#8224;, p&#60;0.001 versus CON post. This figure has been modified from Frank et al. Scand. J. Med. Sci. Sports. 2016: 26, 764-73.28 <a href="https://cloudflare-jove-com.remotexs.ntu.edu.sg/files/ftp_upload/55518/55518fig4large.jpg" target="_blank">Please click here to view a larger version of this figure.</a>
<img alt="Figure 5" class="xfigimg" src="/files/ftp_upload/55518/55518fig5.jpg" /> 
Figure 5: Western blot images. Measured muscle protein before and after eight weeks of intervention. Representative images from one subject in the RET and CON groups, respectively. This figure has been modified from Frank et al. Scand. J. Med. Sci. Sports. 2016: 26, 764-73.28 <a href="https://cloudflare-jove-com.remotexs.ntu.edu.sg/files/ftp_upload/55518/55518fig5large.jpg" target="_blank">Please click here to view a larger version of this figure.</a>
Only the RET group showed an increased aerobic capacity in the cycle test (post- versus pre-test). At the highest submaximal intensity, the heart rate (HR) showed a strong trend to decrease in the RET and rise in the CON group (Figure 6A). In addition, RER (respiratory exchange ratio = CO2/O2) was significantly reduced for the RET group only (Figure 6B).
<img alt="Figure 6" class="xfigimg" src="/files/ftp_upload/55518/55518fig6.jpg" /> 
Figure 6: Cardio respiratory data. Pre- and post-resistance exercise training (RET) or control period (CON). (A) HR, heart rate and (B) RER, respiratory exchange ratio during low- (30 W) and high- (60-120 W) intensity steady-state cycling. Values are from 11 (RET) and 8 (CON) subjects (two subjects were excluded due to asthma and the use of a pacemaker) and are presented as the mean &#177; SEM. (*) p=0.056 (RET) and p=0.068 (CON) versus pre; *p&#60;0.05 versus pre. This figure has been modified from Frank et al. Scand. J. Med. Sci. Sports. 2016: 26, 764-73.28 <a href="https://cloudflare-jove-com.remotexs.ntu.edu.sg/files/ftp_upload/55518/55518fig6large.jpg" target="_blank">Please click here to view a larger version of this figure.</a>
The RET group&#39;s results from the glucose tolerance test showed improved blood glucose, both in blood values after 2 h (14%) and for the area under the curve (21%, Figure 7A).
<img alt="Figure 7" class="xfigimg" src="/files/ftp_upload/55518/55518fig7.jpg" /> 
Figure 7: Plasma glucose during OGTT. The test was performed pre- (&#9679;) and post- (&#9675;) resistance exercise training (RET, A) or a control period (CON, B). AUCglucose, area under the curve for plasma glucose. Values are from 12 (RET) and 9 (CON) subjects and are presented as the mean (plasma glucose) and mean &#177; SEM (AUCglucose). *p&#60;0.05 versus pre. This figure has been modified from Frank et al. Scand. J. Med. Sci. Sports. 2016: 26, 764-73.28 <a href="https://cloudflare-jove-com.remotexs.ntu.edu.sg/files/ftp_upload/55518/55518fig7large.jpg" target="_blank">Please click here to view a larger version of this figure.</a>
The blood lipid profile improved for the RET group, with a decrease in apolipoprotein B (8%). For CON, an increase was found (10%). Furthermore, the fat-free mass (FFM) increased by 3% and the thigh cross-sectional area (CSA) by 7% for the RET group (Table 1). The assessed improvements seen after the short period of progressive strength training in mitochondrial function, aerobic capacity, glucose tolerance, muscle strength, and power are highly desirable health effects in an elderly population.
The eight strength training exercises are shown in Figure 8. Every training task was performed 12 times in each of three sets in every training session 3 times a week for eight weeks.
<img alt="Figure 8" class="xfigimg" src="/files/ftp_upload/55518/55518fig8.jpg" /> 
Figure 8: The eight training exercises. The exercises were performed at 75-80% of 1 RM, 12 times/set, with three sets/exercise and training session. The exercises were: &#34;leg press&#34; and &#34;abdominal crunches&#34; (A), &#34;chest press&#34; and &#34;back extensions&#34; (B), &#34;shoulder press&#34; and &#34;seated rowing&#34; (C), and &#34;leg extensions&#34; and &#34;leg curls&#34; (D). The range of motions in the strength training exercises are shown here. In the seated abdominal crunch, the trunk should be moved from upright position to 60&#176; forward trunk flexion. In seated back extension, the trunk, from an almost upright seated position, is moved backwards to a horizontal lying trunk position. Both the seated exercises, leg presses and leg extensions, were performed starting with the legs in 90&#176; of knee flexion and ending just before the legs were straightened (near 0&#176; in the knees). Leg curls (in the prone position) where done from nearly straightened legs to approximately 100&#176; of knee flexion. Both the seated exercises, chest press and shoulder press, were performed from 90&#176; elbow flexion to just before the arms were straightened (near 0&#176;). <a href="https://cloudflare-jove-com.remotexs.ntu.edu.sg/files/ftp_upload/55518/55518fig8large.jpg" target="_blank">Please click here to view a larger version of this figure.</a>

Watch this Scientific Journal Video about Improving Strength, Power, Muscle Aerobic Capacity, and Glucose Tolerance through Short-term Progressive Strength Training Among Elderly People at JoVE.com

Improving Strength, Power, Muscle Aerobic Capacity, and Glucose Tolerance through Short-term Progressive Strength Training Among Elderly People

The effect of short-term resistance training on elderly people was investigated through the simultaneous use of several methods. Compared to a control group, many improvements were seen, including on muscle aerobic capacity, glucose tolerance, strength, power, and muscle quality (i.e., protein involved in cell signaling and muscle fiber type composition).

This protocol describes the simultaneous use of a broad span of methods to examine muscle aerobic capacity, glucose tolerance, strength, and power in ...

improving-strength-power-muscle-aerobic-capacity-glucose-tolerance

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Muscle Tissue

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12.5K Views.  The Swedish School of Sport and Health Sciences, GIH.  Het effect van de korte termijn weerstand training op ouderen werd onderzocht door het gelijktijdig gebruik van verschillende methoden. Vergeleken met een controlegroep, werden vele verbeteringen gezien, met inbegrip van spier-aërobe capaciteit, glucosetolerantie, sterkte, kracht en spierkwaliteit (dat wil zeggen eiwit dat betrokken is bij celsignaalvorming en samenstelling van spiervezels). 

Video: Improving Strength, Power, Muscle Aerobic Capacity, and Glucose Tolerance through Short-term Progressive Strength Training Among Elderly People

Measuring the Strength of Mice

Kondziela7 devised the inverted screen test and published it in 1964. It is a test of muscle strength using all four limbs. Most normal mice easily score maximum on this task; it is a quick but insensitive gross screen, and the weights test described in this article will provide a finer measure of muscular strength.
There are also several strain gauge-based pieces of apparatus available commercially that will provide more graded data than the inverted screen test, but their cost may put them beyond the reach of many laboratories which do not specialize in strength testing. Hence in 2000 a cheap and simple apparatus was devised by the author. It consists of a series of chain links of increasing length, attached to a "fur collector" a ball of fine wire mesh sold for preventing limescale build up in hard water areas. An accidental observation revealed that mice could grip these very tightly, so they proved ideal as a grip point for a weight-lifting apparatus. A common fault with commercial strength meters is that the bar or other grip feature is not thin enough for mice to exert a maximum grip. As a general rule, the thinner the wire or bar, the better a mouse can grip with its small claws.
This is a pure test of strength, although as for any test motivational factors could potentially play a role. The use of scale collectors, however, seems to minimize motivational problems as the motivation appears to be very high for most normal young adult mice.

Deficits in muscular strength occur in many clinical conditions such as motor neuron disease. The inverted screen and weight lifting tests described here measure strength in mice almost exclusively, with minimal influence of factors such as coordination.

Kondziela7 devised the inverted screen test and published it in 1964. It is a test of muscle strength using all four limbs. Most normal mice easily score ...

Manual Muscle Testing:  A Method of Measuring Extremity Muscle Strength Applied to Critically Ill Patients 

Survivors of acute respiratory distress syndrome (ARDS) and other causes of critical illness often have generalized weakness, reduced exercise tolerance, and persistent nerve and muscle impairments after hospital discharge.1-6 Using an explicit protocol with a structured approach to training and quality assurance of research staff, manual muscle testing (MMT) is a highly reliable method for assessing strength, using a standardized clinical examination, for patients following ARDS, and can be completed with mechanically ventilated patients who can tolerate sitting upright in bed and are able to follow two-step commands. 7, 8 
This video demonstrates a protocol for MMT, which has been taught to &ge;43 research staff who have performed &gt;800 assessments on &gt;280 ARDS survivors. Modifications for the bedridden patient are included. Each muscle is tested with specific techniques for positioning, stabilization, resistance, and palpation for each score of the 6-point ordinal Medical Research Council scale.7,9-11 Three upper and three lower extremity muscles are graded in this protocol: shoulder abduction, elbow flexion, wrist extension, hip flexion, knee extension, and ankle dorsiflexion. These muscles were chosen based on the standard approach for evaluating patients for ICU-acquired weakness used in prior publications. 1,2.

Manual Muscle Testing:  A Method of Measuring Extremity Muscle Strength Applied to Critically Ill Patients

Survivors of acute respiratory distress syndrome (ARDS) and critical illness frequently develop long-lasting muscle weakness. Manual muscle testing (MMT) is a standardized clinical examination commonly used to measure strength of peripheral skeletal muscle groups. This video demonstrates MMT using the 6-point Medical Research Council scale.

Survivors of acute respiratory distress syndrome (ARDS) and other causes of critical illness often have generalized weakness, reduced exercise tolerance, ...

A Murine Model of Muscle Training by Neuromuscular Electrical Stimulation

Neuromuscular electrical stimulation (NMES) is a common clinical modality that is widely used to restore1, maintain2 or enhance3-5 muscle functional capacity. Transcutaneous surface stimulation of skeletal muscle involves a current flow between a cathode and an anode, thereby inducing excitement of the motor unit and the surrounding muscle fibers. 
NMES is an attractive modality to evaluate skeletal muscle adaptive responses for several reasons. First, it provides a reproducible experimental model in which physiological adaptations, such as myofiber hypertophy and muscle strengthening6, angiogenesis7-9, growth factor secretion9-11, and muscle precursor cell activation12 are well documented. Such physiological responses may be carefully titrated using different parameters of stimulation (for Cochrane review, see 13). In addition, NMES recruits motor units non-selectively, and in a spatially fixed and temporally synchronous manner14, offering the advantage of exerting a treatment effect on all fibers, regardless of fiber type. Although there are specified contraindications to NMES in clinical populations, including peripheral venous disorders or malignancy, for example, NMES is safe and feasible, even for those who are ill and/or bedridden and for populations in which rigorous exercise may be challenging. 
Here, we demonstrate the protocol for adapting commercially available electrodes and performing a NMES protocol using a murine model. This animal model has the advantage of utilizing a clinically available device and providing instant feedback regarding positioning of the electrode to elicit the desired muscle contractile effect. For the purpose of this manuscript, we will describe the protocol for muscle stimulation of the anterior compartment muscles of a mouse hindlimb.

A murine model of neuromuscular electrical stimulation (NMES), a safe and inexpensive clinical modality, to the anterior compartment muscles is described. This model has the advantage of modifying a readily available clinical device for the purpose of eliciting targeted and specific muscle contractions in mice.

Neuromuscular electrical stimulation (NMES) is a common clinical modality that is widely used to restore1, maintain2 or enhance3-5 muscle functional ...

Short Session High Intensity Interval Training and Treadmill Assessment in Aged Mice

High intensity interval training (HIIT) is emerging as a therapeutic approach to prevent, delay, or ameliorate frailty. In particular short session HIIT, with regimens less than or equal to 10 min is of particular interest as several human studies feature routines as short as a few minutes a couple times a week. However, there is a paucity of animal studies that model the impacts of short session HIIT. Here, we describe a methodology for an individually tailored and progressive short session HIIT regimen of 10 min given 3 days a week for aged mice using an inclined treadmill. Our methodology also includes protocols for treadmill assessment. Mice are initially acclimatized to the treadmill and then given baseline flat and uphill treadmill assessments. Exercise sessions begin with a 3 min warm-up, then three intervals of 1 min at a fast pace, followed by 1 min at an active recovery pace. Following these intervals, the mice are given a final segment that starts at the fast pace and accelerates for 1 min. The HIIT protocol is individually tailored as the speed and intensity for each mouse are determined based upon initial anaerobic assessment scores. Additionally, we detail the conditions for increasing or decreasing the intensity for individual mice depending on performance. Finally, intensity is increased for all mice every two weeks. We previously reported in this protocol enhanced physical performance in aged male mice and here show it also increases treadmill performance in aged female mice. Advantages of our protocol include low administration time (about 15 min per 6 mice, 3 days a week), strategy for individualizing for mice to better model prescribed exercise, and a modular design that allows for the addition or removal of the number and length of intervals to titrate exercise benefits.

Short session (&#8804;10 min) high intensity interval training (HIIT) is emerging as an alternative to longer exercise modalities, yet the shorter variants are rarely modeled in animal studies. Here, we describe a 10 min, 3 day a week, uphill treadmill HIIT protocol that enhances physical performance in male and female aged mice.

High intensity interval training (HIIT) is emerging as a therapeutic approach to prevent, delay, or ameliorate frailty. In particular short session HIIT, ...

Behavior

Characterization of Metabolic Status in Nonhuman Primates with the Intravenous Glucose Tolerance Test

The intravenous glucose tolerance test (IVGTT) plays a key role in the characterization of glucose homeostasis. When taken together with serum biochemical profiles, inclusive of blood glucose levels in both the fed and fasted state, HbA1c, insulin levels, clinical history of diet, body composition, and body weight status, an assessment of normal and abnormal glycemic control can be made. Interpretation of an IVGTT is done through measurement of changes in glucose and insulin levels over time in relation to the dextrose challenge. Critical components to be considered are: peak glucose and insulin levels reached in relation to T0 (end of glucose infusion), the glucose clearance rate K derived from the slope of rapid glucose clearance in the first 20 min (T1 to T20), the time to return to glucose baseline, and the area under the curve (AUC). These IVGTT measures will show characteristic changes as glucose homeostasis moves from a healthy to a diseased metabolic state5. Herein we will describe the characterization of nonhuman primates (Rhesus and Cynomolgus macaques), which are the most relevant animal model of Type II diabetes (T2D) in humans and the IVGTT and clinical profiles of these animals from a lean healthy, to obese dysmetabolic, and T2D state 8, 10, 11.

The goal of this protocol is to present a standard method to perform intravenous glucose tolerance tests (IVGTTs) to assess glycemic control in nonhuman primates and assess their metabolic status from healthy to dysmetabolic.

The intravenous glucose tolerance test (IVGTT) plays a key role in the characterization of glucose homeostasis. When taken together with serum biochemical ...

Adapted Resistance Training Improves Strength in Eight Weeks in Individuals with Multiple Sclerosis

Hip weakness is a common symptom affecting walking ability in people with multiple sclerosis (MS). It is known that resistance strength training (RST) can improve strength in individuals with MS, however; it remains unclear the duration of RST that is needed to make strength gains and how to adapt hip strengthening exercises for individuals of varying strength using only resistance bands. This paper describes the methodology to set up and implement an adapted resistance strength training program, using resistance bands, for individuals with MS. Directions for pre- and post-strength tests to evaluate efficacy of the strength-training program are included. Safety features and detailed instructions outline the weekly program content and progression. Current evidence is presented showing that significant strength gains can be made within 8 weeks of starting a RST program. Evidence is also presented showing that resistance strength training can be successfully adapted for individuals with MS of varying strength with little equipment.

Hip weakness is a common symptom affecting walking ability in people with multiple sclerosis. Isolated muscle strengthening is a useful method to target specific weaknesses. This protocol describes a progressive resistance-training program using exercise bands to increase hip muscle strength.

Hip weakness is a common symptom affecting walking ability in people with multiple sclerosis (MS). It is known that resistance strength training (RST) can ...

Proximal Cadaveric Femur Preparation for Fracture Strength Testing and Quantitative CT-based Finite Element Analysis

Cadaveric fracture testing is routinely used to understand factors that affect proximal femur strength. Because ex vivo biological tissues are prone to lose their mechanical properties over time, specimen preparation for experimental testing must be performed carefully to obtain reliable results that represent in vivo conditions. For that reason, we designed a protocol and a set of fixtures to prepare the femoral specimens such that their mechanical properties experienced minimal changes. The femora were kept in a frozen state except during preparation steps and mechanical testing. The relevant clinical measures of total hip and femoral neck bone mineral density (BMD) were obtained with a clinical dual X-ray absorptiometry (DXA) bone densitometer, and the 3D geometry and distribution of bone mineral were obtained using CT with a calibration phantom for quantitative estimations based on the greyscale values. Any possible bone disease, fracture, or the presence of implants or artifacts affecting the bone structure, was ruled out with X-ray scans. For preparation, all bones were carefully cleaned of excess soft tissue, and were cut and potted at the internal rotation angle of interest. A cutting fixture allowed the distal end of the bone to be cut off leaving the proximal femur at a desired length. To allow positioning of the femoral neck at prescribed angles during later CT scanning and mechanical testing, the proximal femoral shafts were potted in polymethylmethacrylate (PMMA) using a fixture designed specifically for desired orientations. The data collected from our experiments were then used for validation of quantitative computed tomography (QCT)-based finite element analysis (FEA), as described in a different protocol. In this manuscript, we present the protocol for the precise bone preparation for mechanical testing and subsequent QCT/FEA modeling. The current protocol was successfully applied to prepare about 200 cadaveric femora over a 6-year time period.

We present a robust protocol on how to carefully preserve and prepare cadaveric femora for fracture testing and quantitative computed tomography imaging. The method provides precise control over input conditions for the purpose of determining relationships between bone mineral density, fracture strength, and defining finite element model geometry and properties.

Cadaveric fracture testing is routinely used to understand factors that affect proximal femur strength.  Because ex vivo biological tissues are prone to ...

A Training Program Using an Agility Ladder for Community-Dwelling Older Adults

Aging impairs physical and cognitive functions and limits daily activities. Agility training can improve or maintain physical functioning in older people. The purpose of this study is to report the physical fitness benefits of a training program for independent community-dwelling older adults using an agility ladder. Each training session lasted approximately 30 minutes, and the benefits were achieved with two sessions per week for 14 weeks. Training was timed and involved four different drills and varying levels of difficulty through time. The exercises were performed at the School of Physical Education of the University of Campinas, S&#227;o Paulo state, Brazil. The study participants (n = 16; mean age of 66.9 &#177; 5.0 years) were instructed to perform the exercises as quickly as possible without making mistakes and were assisted by a physical trainer when they made mistakes. Assessments were performed both before and after training using five functional tests (i.e., Illinois agility, five times sit-to-stand, timed up-and-go, walking usual speed, and one-leg stand). Although the study sample was not compared with a control group, the results indicate that training protocols using an agility ladder are easy and practical and improve physical function performance in older adults.

The aim of this study is to present an agility training program for older people. The feasibility of this program is described, and the training protocol demonstrated by video imaging.

Aging impairs physical and cognitive functions and limits daily activities. Agility training can improve or maintain physical functioning in older people. ...

Assessing Strength Exercise Volume and Its Impact on Insulin Sensitivity in Obesity

Randomized Controlled Trial to Study the Acute Effects of Strength Exercise on Insulin Sensitivity in Obese Adults

An acute session of strength exercise (SE) ameliorates insulin sensitivity (IS) for several hours; however, the effects of SE volume (i.e., number of sets) have not been studied thoroughly. Although it is intuitive that some SE is better than none, and more is better than some for the improvement of IS, high-volume sessions might be challenging for diseased populations to complete, especially obese adults, for whom even a brisk walk can be challenging. This protocol details a randomized clinical trial to assess the acute effects of SE on IS in obese adults. The inclusion criteria are body mass index &#62;30 kg/m2, central obesity (waist circumference &#62;88 cm and &#62;102 cm for women and men, respectively), and age &#62;40 years. Participants will be familiarized with the SE (7 exercises targeting major muscle groups) and then will perform three sessions in a randomized order: session 1 - high-volume session (3 sets/exercise); session 2 - low-volume session (1 set/exercise); session 3 - control session (no exercise). Diet will be controlled the day before and on the day of the sessions. Sessions will be completed at night, and an oral glucose tolerance test will be performed the next morning, from which several indexes of IS will be derived, such as the area under the curve (AUC) of glucose and insulin, the Matsuda index, the Cederholm index, the muscle IS index, and the Gutt index. Based on pilot studies, we expect ~15% improvement in IS (insulin AUC, and Matsuda and Cederholm indexes) after the high-volume session, and ~8% improvement after the low-volume session compared to the control session. This study will benefit individuals who find high-volume SE sessions challenging but still aim to improve their IS by investing 1/3 of their time and effort.

Author Spotlight: Exploring the Impact of Reduced Resistance Exercise Volume on Metabolic Health 

This study describes a randomized controlled trial protocol aiming at assessing the acute effects of strength exercise volume on insulin sensitivity in obese individuals.

An acute session of strength exercise (SE) ameliorates insulin sensitivity (IS) for several hours; however, the effects of SE volume (i.e., number of ...

Exploring T2DM Exercise Interventions: A Static Training Device for Mice

Static Strength Training Method for Type 2 Diabetic Mice

The treatment of type 2 diabetes mellitus (T2DM) is a major difficulty in improving patient health. Exercise is one of the main interventions for T2DM. Static strength training is one of the key forms of traditional sports in China. Research shows that static strength training is an effective clinical method for T2DM intervention, but there is no experimental device suitable for static training in mice. One of the difficulties in moving from clinical to basic research is to design appropriate experimental devices. In order to further study the mechanism of static training intervention in T2DM, a simple method for making a static training device for mice is introduced in this paper. This device has the advantages of simple operation, cheap material, and high feasibility. Previous studies conducted under this protocol have shown that static training can effectively reduce blood glucose levels and improve the mitochondrial function of skeletal muscle cells in T2DM mice. The purpose of introducing this device is to promote research on the mechanism of traditional exercise in the intervention of T2DM and to lay a foundation for the quantitative intervention of exercise.

Author Spotlight: Advancing Diabetes Research with Static Exercise Training in Mice

This protocol provides a simple method of making static training equipment for mice. The device maintains the muscle isometric contraction of the limbs of mice so as to verify the intervention effect of traditional exercise on type 2 diabetes (T2DM) and provides new exercise therapy for the clinical treatment of T2DM.

The treatment of type 2 diabetes mellitus (T2DM) is a major difficulty in improving patient health. Exercise is one of the main interventions for T2DM. ...

Improving Strength, Power, Muscle Aerobic Capacity, and Glucose Tolerance through Short-term Progressive Strength Training Among Elderly People

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