Ultrastructural muscle damage in young vs. older men after high-volume, heavy-resistance strength training

1999 ◽  
Vol 86 (6) ◽  
pp. 1833-1840 ◽  
Author(s):  
Stephen M. Roth ◽  
Gregory F. Martel ◽  
Frederick M. Ivey ◽  
Jeffrey T. Lemmer ◽  
Brian L. Tracy ◽  
...  
Keyword(s):  
Strength Training ◽  
Muscle Damage ◽  
Vastus Lateralis ◽  
High Volume ◽  
Older Men ◽  
Group Differences ◽  
Strength Increase ◽  
Significant Group ◽  
Leg Extension ◽  
Old Men

This study assessed ultrastructural muscle damage in young (20–30 yr old) vs. older (65–75 yr old) men after heavy-resistance strength training (HRST). Seven young and eight older subjects completed 9 wk of unilateral leg extension HRST. Five sets of 5–20 repetitions were performed 3 days/wk with variable resistance designed to subject the muscle to near-maximal loads during every repetition. Biopsies were taken from the vastus lateralis of both legs, and muscle damage was quantified via electron microscopy. Training resulted in a 27% strength increase in both groups ( P < 0.05). In biopsies before training in the trained leg and in all biopsies from untrained leg, 0–3% of muscle fibers exhibited muscle damage in both groups ( P = not significant). After HRST, 7 and 6% of fibers in the trained leg exhibited damage in the young and older men, respectively ( P < 0.05, no significant group differences). Myofibrillar damage was primarily focal, confined to one to two sarcomeres. Young and older men appear to exhibit similar levels of muscle damage at baseline and after chronic HRST.

scholarly journals High-volume, heavy-resistance strength training and muscle damage in young and older women

2000 ◽  
Vol 88 (3) ◽  
pp. 1112-1118 ◽  
Author(s):  
Stephen M. Roth ◽  
Gregory F. Martel ◽  
Frederick M. Ivey ◽  
Jeffrey T. Lemmer ◽  
E. Jeffrey Metter ◽  
...  
Keyword(s):  
Strength Training ◽  
Older Women ◽  
Muscle Damage ◽  
Young Women ◽  
Vastus Lateralis ◽  
High Volume ◽  
Knee Extension ◽  
Before And After ◽  
Sedentary Women ◽  
Knee Extension Exercise

To determine possible age differences in muscle damage response to strength training, ultrastructural muscle damage was assessed in seven 20- to 30-yr-old and six 65- to 75-yr-old previously sedentary women after heavy-resistance strength training (HRST). Subjects performed unilateral knee-extension exercise 3 days/wk for 9 wk. Bilateral muscle biopsies from the vastus lateralis were assessed for muscle damage via electron microscopy. HRST resulted in a 38 and 25% increase in strength in the young and older women, respectively ( P < 0.05), but there were no between-group differences. In the young women, 2–4% of muscle fibers exhibited damage before and after training in both the trained and untrained legs ( P = not significant). In contrast, muscle damage increased significantly after HRST, from 5 to 17% of fibers damaged ( P < 0.01), in the older women in the trained leg compared with only 2 and 5% of fibers damaged in the untrained leg before and after training, respectively. The present results indicate that older women exhibit higher levels of muscle damage after chronic HRST than do young women.

Neuromuscular and hormonal adaptations in athletes to strength training in two years

1988 ◽  
Vol 65 (6) ◽  
pp. 2406-2412 ◽  
Author(s):  
K. Hakkinen ◽  
A. Pakarinen ◽  
M. Alen ◽  
H. Kauhanen ◽  
P. V. Komi
Keyword(s):  
Strength Training ◽  
Vastus Lateralis ◽  
Serum Testosterone ◽  
Weight Lifting ◽  
Sex Hormone Binding Globulin ◽  
Strength Development ◽  
Vastus Lateralis Muscle ◽  
Leg Extension ◽  
Intensive Training

Neuromuscular and hormonal adaptations to prolonged strength training were investigated in nine elite weight lifters. The average increases occurred over the 2-yr follow-up period in the maximal neural activation (integrated electromyogram, IEMG; 4.2%, P = NS), maximal isometric leg-extension force (4.9%, P = NS), averaged concentric power index (4.1%, P = NS), total weight-lifting result (2.8%, P less than 0.05), and total mean fiber area (5.9%, P = NS) of the vastus lateralis muscle, respectively. The training period resulted in increases in the concentrations of serum testosterone from 19.8 +/- 5.3 to 25.1 +/- 5.2 nmol/l (P less than 0.05), luteinizing hormone (LH) from 8.6 +/- 0.8 to 9.1 +/- 0.8 U/l (P less than 0.05), follicle-stimulating hormone (FSH) from 4.2 +/- 2.0 to 5.3 +/- 2.3 U/l (P less than 0.01), and testosterone-to-serum sex hormone-binding globulin (SHBG) ratio (P less than 0.05). The annual mean value of the second follow-up year for the serum testosterone-to-SHBG ratio correlated significantly (r = 0.84, P less than 0.01) with the individual changes during the 2nd yr in the averaged concentric power. The present results suggest that prolonged intensive strength training in elite athletes may influence the pituitary and possibly hypothalamic levels, leading to increased serum levels of testosterone. This may create more optimal conditions to utilize more intensive training leading to increased strength development.

scholarly journals Effect of resistance training on skeletal muscle-specific force in elderly humans

2004 ◽  
Vol 96 (3) ◽  
pp. 885-892 ◽  
Author(s):  
N. D. Reeves ◽  
M. V. Narici ◽  
C. N. Maganaris
Keyword(s):  
Skeletal Muscle ◽  
Strength Training ◽  
Old Age ◽  
Vastus Lateralis ◽  
Muscle Volume ◽  
Electromyographic Activity ◽  
Specific Force ◽  
Fascicle Length ◽  
Leg Extension ◽  
Muscle Fascicle

This study assessed muscle-specific force in vivo following strength training in old age. Subjects were assigned to training ( n = 9, age 74.3 ± 3.5 yr; mean ± SD) and control ( n = 9, age 67.1 ± 2 yr) groups. Leg-extension and leg-press exercises (2 sets of 10 repetitions at 80% of the 5 repetition maximum) were performed three times/wk for 14 wk. Vastus lateralis (VL) muscle fascicle force was calculated from maximal isometric voluntary knee extensor torque with superimposed stimuli, accounting for the patella tendon moment arm length, ultrasound-based measurements of muscle architecture, and antagonist cocontraction estimated from electromyographic activity. Physiological cross-sectional area (PCSA) was calculated from the ratio of muscle volume to fascicle length. Specific force was calculated by dividing fascicle force by PCSA. Fascicle force increased by 11%, from 847.9 ± 365.3 N before to 939.3 ± 347.8 N after training ( P < 0.05). Due to a relatively greater increase in fascicle length (11%) than muscle volume (6%), PCSA remained unchanged (pretraining: 30.4 ± 8.9 cm2; posttraining: 29.1 ± 8.4 cm2; P > 0.05). Activation capacity and VL muscle root mean square electromyographic activity increased by 5 and 40%, respectively, after training ( P < 0.05), indicating increased agonist neural drive, whereas antagonist cocontraction remained unchanged ( P > 0.05). The VL muscle-specific force increased by 19%, from 27 ± 6.3 N/cm2 before to 32.1 ± 7.4 N/cm2 after training ( P < 0.01), highlighting the effectiveness of strength training for increasing the intrinsic force-producing capacity of skeletal muscle in old age.

ULTRASTRUCTURAL MUSCLE DAMAGE IN OLDER MEN FOLLOWING EIGHT WEEKS OF STRENGTH TRAINING

1998 ◽  
Vol 30 (Supplement) ◽  
pp. 2
Author(s):  
S. M. Roth ◽  
G. F. Martel ◽  
F. M. Ivey ◽  
J. T. Lemmer ◽  
E. J. Metter ◽  
...  
Keyword(s):  
Strength Training ◽  
Muscle Damage ◽  
Older Men

Muscle quality. II. Effects of strength training in 65- to 75-yr-old men and women

1999 ◽  
Vol 86 (1) ◽  
pp. 195-201 ◽  
Author(s):  
B. L. Tracy ◽  
F. M. Ivey ◽  
D. Hurlbut ◽  
G. F. Martel ◽  
J. T. Lemmer ◽  
...  
Keyword(s):  
Strength Training ◽  
Older Women ◽  
Knee Extensor ◽  
Older Men ◽  
Quadriceps Muscle ◽  
Muscle Volume ◽  
Muscle Quality ◽  
Men And Women ◽  
Leg Extension ◽  
Before And After

To determine the effects of strength training (ST) on muscle quality (MQ, strength/muscle volume of the trained muscle group), 12 healthy older men (69 ± 3 yr, range 65–75 yr) and 11 healthy older women (68 ± 3 yr, range 65–73 yr) were studied before and after a unilateral leg ST program. After a warm-up set, four sets of heavy-resistance knee extensor ST exercise were performed 3 days/wk for 9 wk on the Keiser K-300 leg extension machine. The men exhibited greater absolute increases in the knee extension one-repetition maximum (1-RM) strength test (75 ± 2 and 94 ± 3 kg before and after training, respectively) and in quadriceps muscle volume measured by magnetic resonance imaging (1,753 ± 44 and 1,955 ± 43 cm3) than the women (42 ± 2 and 55 ± 3 kg for the 1-RM test and 1,125 ± 53 vs. 1,261 ± 65 cm3 for quadriceps muscle volume before and after training, respectively, in women; both P < 0.05). However, percent increases were similar for men and women in the 1-RM test (27 and 29% for men and women, respectively), muscle volume (12% for both), and MQ (14 and 16% for men and women, respectively). Significant increases in MQ were observed in both groups in the trained leg (both P < 0.05) and in the 1-RM test for the untrained leg (both P < 0.05), but no significant differences were observed between groups, suggesting neuromuscular adaptations in both gender groups. Thus, although older men appear to have a greater capacity for absolute strength and muscle mass gains than older women in response to ST, the relative contribution of neuromuscular and hypertrophic factors to the increase in strength appears to be similar between genders.

Strength training and determinants of VO2max in older men

1990 ◽  
Vol 68 (1) ◽  
pp. 329-333 ◽  
Author(s):  
W. R. Frontera ◽  
C. N. Meredith ◽  
K. P. O'Reilly ◽  
W. J. Evans
Keyword(s):  
Strength Training ◽  
Citrate Synthase ◽  
Fiber Type ◽  
Vastus Lateralis ◽  
Hemoglobin Concentration ◽  
Older Men ◽  
Oxidative Capacity ◽  
Fat Free Mass ◽  
Knee Extensors ◽  
Total Blood

The effects of strength training on maximal aerobic power (VO2max) and some of its determinants were studied in 12 healthy older men (60-72 yr). They underwent 12 wk of strength conditioning of extensors and flexors of each knee with eight repetitions per set, three sets per session, and three sessions per week at 80% of the one repetition maximum (1 RM). Left knee extensors showed a 107% increase in 1 RM, a 10% increase in isokinetic strength at 60 degrees/s, and a 23% increase in total work performed during 25 contractions on an isokinetic dynamometer. Strength measurements of the untrained left elbow extensors showed no change. Leg cycle ergometer VO2max per unit fat-free mass increased by an average 1.9 ml (P = 0.034) whereas arm cycle VO2max was unchanged. Pulmonary function, hemoglobin concentration, erythrocyte volume, plasma volume, and total blood volume did not change. Biopsies of the vastus lateralis showed a 28% increase in mean fiber area, no change in fiber type distribution, a 15% increase in capillaries per fiber, and a 38% increase in citrate synthase activity. The data suggest that the small increase in leg cycle VO2max in older men may be due to adaptations in oxidative capacity and increased mass of the strength-trained muscles.

scholarly journals Effects of Cannabidiol Supplementation on Skeletal Muscle Regeneration after Intensive Resistance Training

Nutrients ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 3028
Author(s):  
Eduard Isenmann ◽  
Sebastian Veit ◽  
Lynn Starke ◽  
Ulrich Flenker ◽  
Patrick Diel
Keyword(s):  
Resistance Training ◽  
Muscle Damage ◽  
Skeletal Muscle Regeneration ◽  
Group Differences ◽  
Serum Concentrations ◽  
Countermovement Jump ◽  
Significant Group ◽  
Significant Group Difference ◽  
Back Squat ◽  
Before And After

Cannabidiol supplements (CBD) are increasingly consumed by athletes to improve regeneration. However, the evidence for the pro-regenerative effects of CBD in sports is quite limited. Therefore, our aim was to investigate the effects of a single CBD supplementation in a six-arm placebo-controlled crossover study after resistance training on performance and muscle damage. Before and after the resistance training, one-repetition maximum in the back squat (1RM BS), countermovement jump (CMJ), and blood serum concentrations of creatine kinase (CK) and myoglobin (Myo) were measured in healthy, well-trained participants. 16 out of 21 participants completed the study and were included in the analysis. In 1RM BS, a significant decrease was observed after 24 h (p < 0.01) but not after 48 and 72 h. A significant group difference was detected after 72 h (p < 0.05; ES = 0.371). In CMJ, no significant changes were observed. The CK and Myo concentrations increased significantly after 24 h (CK: p < 0.001; Myo: p < 0.01), 48 h (CK: p < 0.001; Myo: p < 0.01) and 72 h (CK: p < 0.001; Myo: p < 0.001). After 72 h, significant group differences were observed for both muscle damage biomarkers (CK: p < 0.05 ES = 0.24; Myo: p < 0.05; ES = 0.21). The results show small but significant effects on muscle damage and recovery of squat performance after 72 h. However, more data are required for clearer statements concerning potential pro-regenerative effects of CBD supplementation after resistance training.

Comparison of Auditory, Language, Memory, and Attention Abilities in Children With and Without Listening Difficulties

2020 ◽  
Vol 29 (4) ◽  
pp. 710-727
Author(s):  
Beula M. Magimairaj ◽  
Naveen K. Nagaraj ◽  
Alexander V. Sergeev ◽  
Natalie J. Benafield
Keyword(s):  
Auditory Processing ◽  
Short Term Memory ◽  
Group Differences ◽  
Long Term Memory ◽  
Short Term ◽  
Significant Group ◽  
Term Memory ◽  
Memory And Attention ◽  
Speed And Accuracy

Objectives School-age children with and without parent-reported listening difficulties (LiD) were compared on auditory processing, language, memory, and attention abilities. The objective was to extend what is known so far in the literature about children with LiD by using multiple measures and selective novel measures across the above areas. Design Twenty-six children who were reported by their parents as having LiD and 26 age-matched typically developing children completed clinical tests of auditory processing and multiple measures of language, attention, and memory. All children had normal-range pure-tone hearing thresholds bilaterally. Group differences were examined. Results In addition to significantly poorer speech-perception-in-noise scores, children with LiD had reduced speed and accuracy of word retrieval from long-term memory, poorer short-term memory, sentence recall, and inferencing ability. Statistically significant group differences were of moderate effect size; however, standard test scores of children with LiD were not clinically poor. No statistically significant group differences were observed in attention, working memory capacity, vocabulary, and nonverbal IQ. Conclusions Mild signal-to-noise ratio loss, as reflected by the group mean of children with LiD, supported the children's functional listening problems. In addition, children's relative weakness in select areas of language performance, short-term memory, and long-term memory lexical retrieval speed and accuracy added to previous research on evidence-based areas that need to be evaluated in children with LiD who almost always have heterogenous profiles. Importantly, the functional difficulties faced by children with LiD in relation to their test results indicated, to some extent, that commonly used assessments may not be adequately capturing the children's listening challenges. Supplemental Material https://doi.org/10.23641/asha.12808607

Behavioral and emotional differences between children of divorce and children from intact families: Clinical significance and mediating processes *This study is part of a dissertation () supported from the German research community.

2002 ◽  
Vol 61 (1) ◽  
pp. 5-14 ◽  
Author(s):  
Andreas Schick
Keyword(s):  
Self Esteem ◽  
Research Community ◽  
Children Of Divorce ◽  
Group Differences ◽  
Significant Group ◽  
Intact Families ◽  
Divorce Adjustment ◽  
Theoretical Assumptions ◽  
German Research ◽  
Clinically Significant

The following study is based on a sample of 241 9-13-year-old children (66 children from divorced parents, 175 children from non divorced parents). They were examined for differences regarding anxiety, self-esteem, different areas of competence, and degree of behavior problems. With a focus on the children’s experiences, the clinically significant differences were examined. Clinically significant differences, revealing more negative outcomes for the children of divorce, were only found for social anxiety and unstable performance. The frequency of clinical significant differences was independent of the length of time the parents had been separated. The perceived destructiveness of conflict between the parents one of four facets of interparental conflict in this study functioned as a central mediator of the statistically significant group differences. The children’s perception of the father’s social support was a less reliable indicator of variance. Further studies should try to make underlying theoretical assumptions about the effects of divorce more explicit, to distinguish clearly between mediating variables, and to investigate them with respect to specific divorce adjustment indicators.

scholarly journals Greater Power but Not Strength Gains Using Flywheel Versus Equivolumed Traditional Strength Training in Junior Basketball Players

2021 ◽  
Vol 18 (3) ◽  
pp. 1181
Author(s):  
Marko D. M. Stojanović ◽  
Mladen Mikić ◽  
Patrik Drid ◽  
Julio Calleja-González ◽  
Nebojša Maksimović ◽  
...  
Keyword(s):  
Strength Training ◽  
Training Group ◽  
T Test ◽  
Control Group ◽  
Basketball Players ◽  
Significant Group ◽  
Sprint Time ◽  
Change Of Direction ◽  
Time Interaction ◽  
And Control

The main aim of the present study was to compare the effects of flywheel strength training and traditional strength training on fitness attributes. Thirty-six well trained junior basketball players (n = 36; 17.58 ± 0.50 years) were recruited and randomly allocated into: Flywheel group (FST; n = 12), traditional strength training group (TST; n = 12) and control group (CON; n = 12). All groups attended 5 basketball practices and one official match a week during the study period. Experimental groups additionally participated in the eight-week, 1–2 d/w equivolume intervention conducted using a flywheel device (inertia = 0.075 kg·m−2) for FST or free weights (80%1 RM) for TST. Pre-to post changes in lower limb isometric strength (ISOMET), 5 and 20 m sprint time (SPR5m and SPR20m), countermovement jump height (CMJ) and change of direction ability (t-test) were assessed with analyses of variance (3 × 2 ANOVA). Significant group-by-time interaction was found for ISOMET (F = 6.40; p = 0.000), CMJ (F = 7.45; p = 0.001), SPR5m (F = 7.45; p = 0.010) and T test (F = 10.46; p = 0.000). The results showed a significantly higher improvement in CMJ (p = 0.006; 11.7% vs. 6.8%), SPR5m (p = 0.001; 10.3% vs. 5.9%) and t-test (p = 0.045; 2.4% vs. 1.5%) for FST compared to the TST group. Simultaneously, th FST group had higher improvement in ISOMET (p = 0.014; 18.7% vs. 2.9%), CMJ (p = 0.000; 11.7% vs. 0.3%), SPR5m (p = 0.000; 10.3% vs. 3.4%) and t-test (p = 0.000; 2.4% vs. 0.6%) compared to the CON group. Players from the TST group showed better results in CMJ (p = 0.006; 6.8% vs. 0.3%) and t-test (p = 0.018; 1.5% vs. 0.6%) compared to players from the CON group. No significant group-by-time interaction was found for sprint 20 m (F = 2.52; p = 0.088). Eight weeks of flywheel training (1–2 sessions per week) performed at maximum concentric intensity induces superior improvements in CMJ, 5 m sprint time and change of direction ability than equivolumed traditional weight training in well trained junior basketball players. Accordingly, coaches and trainers could be advised to use flywheel training for developing power related performance attributes in young basketball players.

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