Time Course of Resistance Training–Induced Muscle Hypertrophy in the Elderly (original) (raw)
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The Effects of High- and Moderate-Resistance Training on Muscle Function in the Elderly
Journal of Aging and Physical Activity, 2004
The purpose of this study was to investigate the effects of a 12-week resistance-training program on muscle strength and mass in older adults. Thirty-three inactive participants (60–74 years old) were assigned to 1 of 3 groups: high-resistance training (HT), moderate-resistance training (MT), and control. After the training period, both HT and MT significantly increased 1-RM body strength, the peak torque of knee extensors and flexors, and the midthigh cross-sectional area of the total muscle. In addition, both HT and MT significantly decreased the abdominal circumference. HT was more effective in increasing 1-RM strength, muscle mass, and peak knee-flexor torque than was MT. These data suggest that muscle strength and mass can be improved in the elderly with both high- and moderate-intensity resistance training, but high-resistance training can lead to greater strength gains and hypertrophy than can moderate-resistance training.
Resistance training induced increase in muscle fiber size in young and older men
European Journal of Applied Physiology, 2013
Muscle strength and mass decline in sedentary individuals with aging. The present study investigated the effects of both age and 21 weeks of progressive hypertrophic resistance training (RT) on skeletal muscle size and strength, and on myostatin and myogenin mRNA expression in 21 previously untrained young men (26.0 ± 4.3 years) and 18 older men (61.2 ± 4.1 years) and age-matched controls. Vastus lateralis muscle biopsies were taken before and after RT. Type I and type II muscle fiber cross-sectional areas increased more in young men than in older men after RT (P \ 0.05). Concentric leg extension increased (P \ 0.05) more after 10.5 weeks in young men compared to older men, but after 21 weeks no statistical differences existed. The daily energy and protein intake were greater (P \ 0.001) in young subjects. Both myostatin and myogenin mRNA expression increased in older when compared with young men after RT (P \ 0.05). In conclusion, after RT, muscle fiber size increased less in older compared to young men. This was associated with lower protein and energy intake and increases in myostatin gene expression in older when compared to young men.
Experimental Gerontology, 2013
Muscle adaptations can be induced by high-resistance exercise. Despite being potentially more suitable for older adults, low-resistance exercise protocols have been less investigated. We compared the effects of high-and low-resistance training on muscle volume, muscle strength, and force-velocity characteristics. Fifty-six older adults were randomly assigned to 12 weeks of leg press and leg extension training at either HIGH (2 × 10-15 repetitions at 80% of one repetition maximum (1RM)), LOW (1 × 80-100 repetitions at 20% of 1RM), or LOW+ (1 × 60 repetitions at 20% of 1RM, followed by 1 × 10-20 repetitions at 40% of 1RM). All protocols ended with muscle failure. Leg press and leg extension of 1RM were measured at baseline and post intervention and before the first training session in weeks 5 and 9. At baseline and post intervention, muscle volume (MV) was measured by CT-scan. A Biodex dynamometer evaluated knee extensor static peak torque in different knee angles (PT stat90°, PT stat120°, PT stat150°) , dynamic peak torque at different speeds (PT dyn60°s −1 , PT dyn180°s −1 , PT dyn240°s −1 ), and speed of movement at 20% (S 20 ), 40% (S 40 ), and 60% (S 60 ) of PT stat90°. HIGH and LOW+ resulted in greater improvements in 1RM strength than LOW (p b 0.05). These differences were already apparent after week 5. Similar gains were found between groups in MV, PT stat , PT dyn60°s −1 , and PT dyn180°s −1
International Journal of Sport, Exercise and Health Research
The purpose of this study was to examine skeletal muscle strength and size gains that may occur during 4 and 8wk of high-intensity resistance training in physically-active older women. Fifteen regularly aerobic-exercising women (age 63-77 y) were randomly placed into a weight-training group (WTG) (n=8) or control group (CG) (n=7). Weight training consisted of bilateral knee extension (BLE), knee flexion (BKF) and leg press (BLP) (3 d•wk-1 , 3 sets, 80% 1-RM). Subjects exercised to full-range failure (6-10 repetitions) and then attempted 2 additional partial reps on each set. When 10 full reps were completed, resistance was increased to allow for only 6 full reps on the subsequent set. Assessments of skeletal muscle strength and size were made in WTG and CG at 0, 4 and 8wk. All measures of strength (1-RM) increased (p<0.001) in WTG after 4wk and 8wk of training. BLE increased 78 and 125%, BKF increased 99 and 156% and BLP increased 42% and 60% after 4wk and 8wk, respectively. Thigh muscle volume (cm 3) was measured by obtaining 10 contiguous 10mm thick images of both thighs using T1 weighted magnetic resonance imaging. Muscle volume increased 2.4% (p=0.01) after 4wk and 6.7% (p<0.001) after 8wk in WTG. Muscle strength and size of CG did not change. This study confirms that older women can increase strength dramatically with training. This study also demonstrates that physically-active older muscles are capable of significant hypertrophy after as few as 4wk of highintensity training.
Muscle architecture and strength: Adaptations to short-term resistance training in older adults
Muscle & Nerve, 2014
Introduction: Muscle morphology and architecture changes in response to 6 weeks of progressive resistance training were examined in healthy older adults. Methods: In this randomized, controlled design, muscle strength, quality, and architecture were evaluated with knee extension, DEXA, and ultrasound, respectively, in 25 older adults. Results: Resistance training resulted in significant increases in strength and muscle quality of 32% and 31%, respectively. Cross-sectional area of the vastus lateralis increased by 7.4% (p 0.05). Physiological cross-sectional area (PCSA) of the thigh, a composite measure of muscle architecture, was related significantly to strength (r 5 0.57; p 0.01) and demonstrated a significant interaction after training (p 0.05). Change in PCSA of the vastus lateralis was associated with change in strength independent of any other measure. Conclusions: Six weeks of resistance training was effective at increasing strength, muscle quality, and muscle morphology in older adult men and women.
Improved skeletal muscle mass and strength after heavy strength training in very old individuals
Experimental Gerontology, 2017
Age-related loss of muscle mass and function represents personal and socioeconomic challenges. The purpose of this study was to determine the adaptation of skeletal musculature in very old individuals (83+ years) performing 12 weeks of heavy resistance training (3x/week) (HRT) compared to a non-training control group (CON). Both groups received similar protein supplementations. We studied 26 participants (86.9 ± 3.2 (SD) (83-94, range) years old) perprotocol. Quadriceps cross-sectional area (CSA) differed between groups at post-test (P < 0.05) and increased 1.5 ± 0.7 cm 2 (3.4%) (P < 0.05) in HRT only. The relative increase in CSA correlated inversely with the baseline level of CSA (R 2 = 0.43, P < 0.02). Thigh muscle isometric strength, isokinetic peak torque and power increased significantly only in HRT by 10-15%, whereas knee extension one-repetition maximum (1 RM) improved by 91%. Physical functional tests, muscle fiber type distribution and size did not differ significantly between groups. We conclude that in protein supplemented very old individuals, heavy resistance training can increase muscle mass and strength, and that the relative improvement in mass is more pronounced when initial muscle mass is low.
Effects of order of resistance training exercises on muscle hypertrophy in young adult men
The purpose of the present study was to analyze the effects of the order of resistance training (RT) exercises on hypertrophy in young adult men. Thirty-six young adult men (age, 21.9 ± 2.5 years; body mass, 72.6 ± 12.1 kg, height, 176.9 ± 7.4 cm; body mass index, 23.1 ± 3.3 kg/m 2) were randomly assigned to 1 of 2 training groups that performed a 6-week RT program in either (i) a traditional approach starting with multi-joint (MJ) exercises followed by single-joint exercises (SJ) (MJ-SJ, n = 19) or (ii) in reverse order (SJ-MJ, n = 17). Muscle thickness of the biceps brachii and mid-thigh were assessed by ultrasound. Lean soft tissue (LST) was assessed by dual-energy X-ray absorptiometry. Both groups similarly increased (P < 0.05) biceps brachii thickness (MJ-SJ = +14.2%, SJ-MJ = +13.8%). Alternatively, only the MJ-SJ group presented an increase in mid-thigh thickness from pre-to post-training (MJ-SJ = +7.2%, SJ-MJ = +3.9%). Upper limb LSTs (MJ-SJ = +5.2%, SJ-MJ = +7.5%) were statistically similar between conditions, and a trend for significance (P = 0.07) was found for trunk LST (MJ-SJ = +7.2%, SJ-MJ = +1.7%). Nonsignificant pre-to post-training changes were observed for lower limb LSTs (MJ-SJ = +0.7%, SJ-MJ = +1.8%). Our data suggest that both sequences are effective for increasing muscle hypertrophy over a short-term RT period; there may be a potentially beneficial hypertrophic effect for the mid-thigh by performing exercises in a manner that progresses from MJ to SJ exercises.
An examination of the time course of training-induced skeletal muscle hypertrophy
Skeletal muscle hypertrophy is typically considered to be a slow process. However, this is partly because the time course for hypertrophy has not been thoroughly examined. The purpose of this study was to use weekly testing to determine a precise time course of skeletal muscle hypertrophy during a resistance training program. Twenty-Wve healthy, sedentary men performed 8 weeks of high-intensity resistance training. Whole muscle cross-sectional area (CSA) of the dominant thigh was assessed using a peripheral quantitative computed tomography scanner during each week of training (W1-W8). Isometric maximum voluntary contractions (MVC) were also measured each week. After only two training sessions (W1), the mean thigh muscle CSA increased by 5.0 cm 2 (3.46%; p < 0.05) from the pre-testing (P1) and continued to increase with each testing session. It is possible that muscular edema may have inXuenced the early CSA results. To adjust for this possibility, with edema assumedly at its highest at W1, the next signiWcant increase from W1 was at W3. W4 was the Wrst signiWcant increase of MVC over P1. Therefore, signiWcant skeletal muscle hypertrophy likely occurred around weeks 3-4. Overall, from the pre-testing to W8, there was an increase of 13.9 cm 2 (9.60%). These Wndings suggested that training-induced skeletal muscle hypertrophy may occur early in a training program.
AGE, 2014
This study investigated the effects of low-and high-volume strength trainings on neuromuscular adaptations of lower-and upper-body muscles in older women after 6 weeks (6WE), 13 weeks (13WE), and 20 weeks (20WE) of training. Healthy older women were assigned to low-volume (LV) or high-volume (HV) training groups. The LV group performed one set of each exercise, while the HV group performed three sets, 2 days/ week. Knee extension and elbow flexion one-repetition maximum (1-RM), maximal isometric strength, maximal muscle activation, and muscle thickness (MT) of the lower-and upper-body muscles, as well as lower-body muscle quality (MQ) obtained by ultrasonography, were evaluated. Knee extension and elbow flexion 1-RM improved at all time points for both groups; however, knee extension 1-RM gains were greater for the HV group after 20WE. Maximal isometric strength of the lower body for both groups increased only at 20WE, while upper-body maximal isometric strength increased after 13WE and 20WE. Maximal activation of the lower and upper body for both groups increased only after 20WE. Both groups showed significant increases in MT of their lower and upper body, with greater gains in lower-body MT for the HV group at 20WE. MQ improved in both groups after 13WE and 20WE, whereas the HV group improved more than the LV group at 20WE. These results showed that low-and high-volume trainings have a similar adaptation time course in the muscular function of upper-body muscles. However, high-volume training appears to be more efficient for lower-body muscles after 20 weeks of training.
Aging and Disease, 2016
Muscle power is a strong predictor of functional status in the elderly population and is required to perform different daily activities. To compare the effects of different weekly training frequencies on muscle power and muscle quality induced by concurrent training (resistance + aerobic) in previously trained elderly men. Twenty-four trained elderly men (65 ± 4 years), previously engaged in a regular concurrent training program, three times per week, for the previous five months, were randomly allocated to concurrent training programs in which training was performed either twice a week (2• week-1 , n = 12) or three times per week (3• week-1 , n = 12). The groups trained with an identical exercise intensity and volume per session for 10 weeks. Before and after the exercise training, we examined muscle power, as estimated by countermovement jump height; knee extensor isokinetic peak torque at 60 and 180 o. s-1 ; and muscle quality, a quotient between the one-repetition maximum of the knee extensors and the sum of quadriceps femoris muscle thickness determined by ultrasonography. Additionally, as secondary outcomes, blood pressure and reactive hyperemia were evaluated. Two-way ANOVA with repeated measures were used and statistical significance was set at α = 0.05. Muscular power (2• week-1 : 7%, and 3• week-1 : 10%) and muscle quality (2• week-1 : 15%, and 3• week-1 : 8%) improved with the concurrent exercise training (p < 0.001) but with no differences between groups. The isokinetic peak torque at 60 (2• week-1 : 4%, and 3• week-1 : 2%) and 180 o. s-1 (2• week-1 : 7%, and 3• week-1 : 1%) increased in both groups (p = 0.036 and p=0.014, respectively). There were no changes in blood pressure or reactive hyperemia with the concurrent training. Concurrent training performed twice a week promotes similar adaptations in muscular power and muscle quality when compared with the same program performed three times per week in previously trained elderly men.