Biomedical subjects

B F Hurley

Publications and source records attributed to B F Hurley.

At least 19 recordsLinked to original sources

PubMed2002

IGF2 genotype and obesity in men and women across the adult age span.

We studied a previously reported association between the IGF2 gene's ApaI polymorphism and obesity in 500 healthy men and women (19-90 y). We hypothesized that individuals homozygous for the IGF2 A allele (A/A) would exhibit lower body mass, BMI and DEXA-measured fat mass compared to G/G homozygotes. Subjects were categorized as exhibiting the G/G (n = 241), G/A (n = 197) or A/A (n = 62) genotype. Contrary to our hypothesis, no difference was observed in body mass, body mass index (BMI) or fat mass between the G/G and A/A genotype groups in the entire cohort. Surprisingly, Caucasian A/A individuals (n = 427) exhibited significantly higher fat mass compared to Caucasian G/G individuals (P < 0.05). In summary, individuals homozygous for the IGF2 G allele do not exhibit higher body mass, BMI or fat mass compared to A/A individuals; however, Caucasians with the A/A genotype exhibit higher fat mass than G/G individuals.

Adipose Tissue↗

PubMed2002

Does age, sex, or ACE genotype affect glucose and insulin responses to strength training?

The purpose of the present study was to determine whether age, sex, or angiotensin I-converting enzyme (ACE) genotype influences the effects of strength training (ST) on glucose homeostasis. Nineteen sedentary young (age = 20-30 yr) men (n = 10) and women (n = 9) were studied and compared with 21 sedentary older (age = 65-75 yr) men (n = 12) and women (n = 9) before and after a 6-mo total body ST program. Fasting insulin concentrations were reduced in young men and in older men with ST (P < 0.05 in both). In addition, total insulin area under the curve decreased by 21% in young men (P < 0.05), and there was a trend for a decrease (11%) in older men (P = 0.06). No improvements in insulin responses were observed in young or older women. The ACE deletion/deletion genotype group had the lowest fasting insulin and insulin areas under the oral glucose tolerance test (OGTT) curve before training (all P < 0.05), but those with at least one insertion allele had a trend for a greater reduction in total insulin area than deletion homozygotes (P = 0.07). These results indicate that ST has a more favorable effect on insulin response to an OGTT in men than in women and offer some support for the hypothesis that ACE genotype may influence insulin responses to ST.

Adult↗

PubMed2001

Muscle size responses to strength training in young and older men and women.

OBJECTIVES: To examine the possible influences of age and gender on muscle volume responses to strength training (ST). DESIGN: Prospective intervention study. SETTING: University of Maryland Exercise Science and Wellness Research Laboratories. PARTICIPANTS: Eight young men (age 20-30 years), six young women (age 20-30 years), nine older men (age 65-75 years), and ten older women (age 65-75 years). INTERVENTION: A 6-month whole-body ST program that exercised all major muscle groups of the upper and lower body 3 days/week. MEASUREMENTS: Thigh and quadriceps muscle volumes and mid-thigh muscle cross-sectional area (CSA) were assessed by magnetic resonance imaging before and after the ST program. RESULTS: Thigh and quadriceps muscle volume increased significantly in all age and gender groups as a result of ST (P < .001), with no significant differences between the groups. Modest correlations were observed between both the change in quadriceps versus the change in total thigh muscle volume (r = 0.65; P < .001) and the change in thigh muscle volume versus the change in mid-thigh CSA (r = 0.76, P < .001). CONCLUSIONS: The results indicate that neither age nor gender affects muscle volume response to whole-body ST. Muscle volume, rather than muscle CSA, is recommended for studying muscle mass responses to ST.

Adult↗

PubMed2001

Insulin action after resistive training in insulin resistant older men and women.

OBJECTIVES: To determine the effects of resistive training (RT) on insulin action and assess the determinants of the changes in insulin action. DESIGN: Longitudinal study. SETTING: Outpatient setting. PARTICIPANTS: Eighteen older men and older postmenopausal women (65-74 years) with normal (6 men and 5 women) or impaired glucose tolerance (4 men and 3 women). INTERVENTION: Six months of progressive whole-body RT. MEASUREMENTS: Upper and lower body strength was assessed by the one repetition maximum test. Total body fat and fat-free mass (FFM) were determined by dual-energy x-ray absorptiometry before and after 6 months of RT. Insulin sensitivity was estimated from the relationship of glucose utilization (M) to the concentration of insulin (I) during the last 30 minutes of 3-hour hyperinsulinemic-euglycenic clamps (240 pmol x min(-2) x min(-1)) (M/I) before and after RT. RESULTS: RT significantly improved upper- and lower-body muscular strength (P < .005). FFM increased after RT in the entire group (P < .01) with no significant change in body fat. Although the change in M was larger in men (13%) than women (3%), the difference was not significant. The change in M was a function of initial M (r = -0.53, P < .05). There was a trend (0.060+/-0.006 vs 0.066+/-0.006 micromol x kg(-1) x min(-1)/pmol/l, n = 18) for M/I to increase after RT in the combined group of men and women (P = .06). There were no significant relationships between changes in M or M/I with changes in body composition or strength. CONCLUSION: A 6-month RT program tends to improve insulin action in insulin-resistant older adults. These results suggest that RT may be useful in ameliorating insulin resistance that often occurs with physical inactivity, obesity, and loss of muscular strength in older insulin resistant men and women.

Aged↗

PubMed2001

Skeletal muscle satellite cell characteristics in young and older men and women after heavy resistance strength training.

Skeletal muscle satellite cell proportions and morphology were assessed in healthy, sedentary young and older men and women in response to heavy resistance strength training (HRST). Fourteen young (20-30 years) men (n = 7) and women (n = 7) and 15 older (65-75 years) men (n = 8) and women (n = 7) completed 9 weeks of unilateral knee extension exercise training 3 days per week. Muscle biopsies were obtained from each vastus lateralis before and after training, with the nondominant leg serving as an untrained control. All four groups demonstrated a significant increase in satellite cell proportion in response to HRST (2.3 +/- 0.4% vs 3.1 +/- 0.4% for all subjects combined, before and after training, respectively; p < .05), with older women demonstrating the greatest increase (p < .05). Morphology data indicated a significant increase in the proportion of active satellite cells in after-training muscle samples compared with before-training samples and with control leg samples (31% vs 6% and 7%, respectively; p < .05). The present results indicate that the proportion of satellite cells is increased after HRST in young and older men and women, with an exaggerated response in older women. Furthermore, the proportion of satellite cells that appear morphologically active is increased as a result of HRST.

Adult↗

PubMed2001

Effect of strength training on resting metabolic rate and physical activity: age and gender comparisons.

PURPOSE: The purpose of this study was to compare age and gender effects of strength training (ST) on resting metabolic rate (RMR), energy expenditure of physical activity (EEPA), and body composition. METHODS: RMR and EEPA were measured before and after 24 wk of ST in 10 young men (20-30 yr), 9 young women (20-30 yr), 11 older men (65-75 yr), and 10 older women (65-75 yr). RESULTS: When all subjects were pooled together, absolute RMR significantly increased by 7% (5928 +/- 1225 vs 6328 +/- 1336 kJ.d-1, P < 0.001). Furthermore, ST increased absolute RMR by 7% in both young (6302 +/- 1458 vs 6719 +/- 1617 kJ x d(-1), P < 0.01) and older (5614 +/- 916 vs 5999 +/- 973 kJ x d(-1), P < 0.05) subjects, with no significant interaction between the two age groups. In contrast, there was a significant gender x time interaction (P < 0.05) for absolute RMR with men increasing RMR by 9% (6645 +/- 1073 vs 7237 +/- 1150 kJ x d(-1), P < 0.001), whereas women showed no significant increase (5170 +/- 884 vs 5366 +/- 692 kJ x d(-1), P = 0.108). When RMR was adjusted for fat-free mass (FFM) using ANCOVA, with all subjects pooled together, there was still a significant increase in RMR with ST. Additionally, there was still a gender effect (P < 0.05) and no significant age effect (P = NS), with only the men still showing a significant elevation in RMR. Moreover, EEPA and TEE estimated with a Tritrac accelerometer and TEE estimated by the Stanford Seven-Day Physical Activity Recall Questionnaire did not change in response to ST for any group. CONCLUSIONS: In conclusion, changes in absolute and relative RMR in response to ST are influenced by gender but not age. In contrast to what has been suggested previously, changes in body composition in response to ST are not due to changes in physical activity outside of training.

Adult↗

PubMed2001

CNTF genotype is associated with muscular strength and quality in humans across the adult age span.

The relationship between ciliary neurotrophic factor (CNTF) genotype and muscle strength was examined in 494 healthy men and women across the entire adult age span (20-90 yr). Concentric (Con) and eccentric (Ecc) peak torque were assessed using a Kin-Com isokinetic dynamometer for the knee extensors (KE) and knee flexors (KF) at slow (0.52 rad/s) and faster (3.14 rad/s) velocities. The results were covaried for age, gender, and body mass or fat-free mass (FFM). Individuals heterozygous for the CNTF null (A allele) mutation (G/A) exhibited significantly higher Con peak torque of the KE and KF at 3.14 rad/s than G/G homozygotes when age, gender, and body mass were covaried (P < 0.05). When the dominant leg FFM (estimated muscle mass) was used in place of body mass as a covariate, Con peak torque of the KE at 3.14 rad/s was also significantly greater in the G/A individuals (P < 0.05). In addition, muscle quality of the KE (peak torque at 3.14 rad x s(-1) x leg muscle mass(-1)) was significantly greater in the G/A heterozygotes (P < 0.05). Similar results were seen in a subanalysis of subjects 60 yr and older, as well as in Caucasian subjects. In contrast, A/A homozygotes demonstrated significantly lower Ecc peak torque at 0.52 rad/s for both KE and KF compared with G/G and G/A groups (P < 0.05). No significant relationships were observed at 0.52 rad/s between genotype and Con peak torque. These data indicate that individuals exhibiting the G/A genotype possess significantly greater muscular strength and muscle quality at relatively fast contraction speeds than do G/G individuals. Because of high positive correlations between fast-velocity peak torque and muscular power, these findings suggest that further investigations should address the relationship between CNTF genotype and muscular power.

Adult↗

PubMed2000

Skeletal muscle satellite cell populations in healthy young and older men and women.

The purpose of the present investigation was to assess satellite cell populations and morphology in m. vastus lateralis biopsies obtained from young (20-30 years) and older (65-75 years) healthy, sedentary men and women. Multiple muscle biopsies were obtained from 14 young individuals (men, n = 7; women, n = 7) and 15 older individuals (men, n = 8; women, n = 7). Muscle fibers were viewed longitudinally using a Zeiss EM 10 CA electron microscope. All myonuclei and satellite cells were counted and satellite cells were photographed for morphological analysis. The proportion of satellite cells [satellite cells/(myonuclei + satellite cells)] did not differ among the four subject groups (1.7-2.8%), nor did proportions differ when subject groups were combined for age and gender comparisons. Few morphological differences were noted between groups; however, lipofuscin granules were more prominent in satellite cells from older subjects and women demonstrated significantly larger satellite cell and satellite cell nucleus areas than men. Mitochondria from satellite cells (regardless of group) were more pallid and exhibited fewer cristae than mitochondria located in the adjacent muscle fiber. The results of the current investigation suggest that, despite findings in animal models, satellite cell populations are not significantly lower in healthy, sedentary older compared to young adult men and women.

Adult↗

PubMed2000

Effects of age, gender, and myostatin genotype on the hypertrophic response to heavy resistance strength training.

BACKGROUND: Because of the scarcity of data available from direct comparisons of age and gender groups using the same relative training stimulus, it is unknown whether older individuals can increase their muscle mass as much as young individuals and whether women can increase as much as men in response to strength training (ST). In addition, little is known about whether the hypertrophic response to ST is affected by myostatin genotype, a candidate gene for muscle hypertrophy. METHODS: Eleven young men (25 +/- 3 years, range 21-29 years), 11 young women (26 +/- 2 years, range 23-28 years), 12 older men (69 +/- 3 years, range 65-75 years), and 11 older women (68 +/- 2 years, range 65-73 years) had bilateral quadriceps muscle volume measurements performed using magnetic resonance imaging (MRI) before and after ST and detraining. Training consisted of knee extension exercises of the dominant leg three times per week for 9 weeks. The contralateral limb was left untrained throughout the ST program. Following the unilateral training period, the subjects underwent 31 weeks of detraining during which no regular exercise was performed. Myostatin genotype was determined in a subgroup of 32 subjects, of which five female subjects were carriers of a myostatin gene variant. RESULTS: A significantly greater absolute increase in muscle volume was observed in men than in women (204 +/- 20 vs 101 +/- 13 cm3, p < .01), but there was no significant difference in muscle volume response to ST between young and older individuals. The gender effect remained after adjusting for baseline muscle volume. In addition, there was a significantly greater loss of absolute muscle volume after 31 weeks of detraining in men than in women (151 +/- 13 vs 88 +/- 7 cm3, p < .05), but no significant difference between young and older individuals. Myostatin genotype did not explain the hypertrophic response to ST when all 32 subjects were assessed. However, when only women were analyzed, those with the less common myostatin allele exhibited a 68% larger increase in muscle volume in response to ST (p = .056). CONCLUSIONS: Aging does not affect the muscle mass response to either ST or detraining, whereas gender does, as men increased their muscle volume about twice as much in response to ST as did women and experienced larger losses in response to detraining than women. Young men were the only group that maintained muscle volume adaptation after 31 weeks of detraining. Although myostatin genotype may not explain the observed gender difference in the hypertrophic response to ST, a role for myostatin genotype may be indicated in this regard for women, but future studies are needed with larger subject numbers in each genotype group to confirm this observation.

Adult↗

PubMed2000

Effects of strength training and detraining on muscle quality: age and gender comparisons.

Maximal force production per unit of muscle mass (muscle quality, or MQ) has been used to describe the relative contribution of non-muscle-mass components to the changes in strength with age and strength training (ST). To compare the influence of age and gender on MQ response to ST and detraining, 11 young men (20-30 years), nine young women (20-30 years), 11 older men (65-75 years), and 11 older women (65-75 years), were assessed for quadriceps MQ at baseline, after 9 weeks of ST, and after 31 weeks of detraining. MQ was calculated by dividing quadriceps one repetition maximum (IRM) strength by quadriceps muscle volume determined by magnetic resonance imaging. All groups demonstrated significant increases in IRM strength and muscle volume after training (all p < .05). All groups also increased their MQ with training (all p < .01), but the gain in MQ was significantly greater in young women than in the other three groups (p < .05). After 31 weeks of detraining, MQ values remained significantly elevated above baseline levels in all groups (p < .05), except the older women. These results indicate that factors other than muscle mass contribute to strength gains with ST in young and older men and women, but those other factors may account for a higher portion of the strength gains in young women. These factors continue to maintain strength levels above baseline for up to 31 weeks after cessation of training in young men and women, and in older men.

Adult↗

PubMed2000

Age and gender responses to strength training and detraining.

PURPOSE: The purpose of this study was to examine the effects of age and gender on the strength response to strength training (ST) and detraining. METHODS: Eighteen young (20-30 yr) and 23 older (65-75 yr) men and women had their one-repetition maximum (1 RM) and isokinetic strength measured before and after 9 wk of unilateral knee extension ST (3 d x wk(-1)) and 31 wk of detraining. RESULTS: The young subjects demonstrated a significantly greater (P < 0.05) increase in 1 RM strength (34+/-3%; 73+/-5 vs 97+/-6 kg; P < 0.01) than the older subjects (28+/-3%; 60+/-4 vs 76+/-5 kg, P < 0.01). There were no significant differences in strength gains between men and women in either age group with 9 wk of ST or in strength losses with 31 wk of detraining. Young men and women experienced an 8+/-2% decline in 1 RM strength after 31 wk of detraining (97+/-6 vs 89+/-6 kg, P < 0.05). This decline was significantly less than the 14+/-2% decline in the older men and women (76+/-5 vs 65+/-4 kg, P < 0.05). This strength loss occurred primarily between 12 and 31 wk of detraining with a 6+/-2% and 13+/-2% decrease in the young and older subjects, respectively, during this period. DISCUSSION: These results demonstrate that changes in 1 RM strength in response to both ST and detraining are affected by age. However, ST-induced increases in muscular strength appear to be maintained equally well in young and older men and women during 12 wk of detraining and are maintained above baseline levels even after 31 wk of detraining in young men, young women, and older men.

Adult↗

PubMed2000

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

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.

Adult↗

PubMed2000

Strength training in the elderly: effects on risk factors for age-related diseases.

Strength training (ST) is considered a promising intervention for reversing the loss of muscle function and the deterioration of muscle structure that is associated with advanced age. This reversal is thought to result in improvements in functional abilities and health status in the elderly by increasing muscle mass, strength and power and by increasing bone mineral density (BMD). In the past couple of decades, many studies have examined the effects of ST on risk factors for age-related diseases or disabilities. Collectively, these studies indicate that ST in the elderly: (i) is an effective intervention against sarcopenia because it produces substantial increases in the strength, mass, power and quality of skeletal muscle; (ii) can increase endurance performance; (iii) normalises blood pressure in those with high normal values; (iv) reduces insulin resistance; (v) decreases both total and intra-abdominal fat; (vi) increases resting metabolic rate in older men; (vii) prevents the loss of BMD with age; (viii) reduces risk factors for falls; and (ix) may reduce pain and improve function in those with osteoarthritis in the knee region. However, contrary to popular belief, ST does not increase maximal oxygen uptake beyond normal variations, improve lipoprotein or lipid profiles, or improve flexibility in the elderly.

Accidental Falls↗

PubMed2000

Strength training for the prevention and treatment of sarcopenia.

There is a progressive loss of muscle strength, muscle mass and muscle quality with advanced age, which results in a condition known as sarcopenia. In this review, the authors outline the magnitude of these losses, their functional consequences, and the efficacy of strength training (ST) as an intervention strategy for delaying, preventing or reversing the effects of sarcopenia. The question of whether sex differences and genetics influence the effects of sarcopenia and responses to ST are also discussed. Although many potential mechanisms for sarcopenia exist, their specific contributions are still unknown. Nevertheless, proposed mechanisms of sarcopenia are outlined and, where information is available, we examine the effects of ST on these potential mechanisms, which include neurogenic factors, anabolic hormones, protein synthesis, gene expression, muscle morphology, and muscle regeneration. Finally, the potential impact of genetics in the muscle response to both sarcopenia and ST is discussed. The evidence presented suggests that ST is an effective intervention for improving strength, muscle mass and muscle quality and delaying the onset of physical disability in the elderly. However, sex differences and genetic factors may play an important role in determining the muscular response to aging and ST.

Aged↗

PubMed1999

Frequent sequence variation in the human myostatin (GDF8) gene as a marker for analysis of muscle-related phenotypes.

Myostatin is a recently identified member of the transforming growth factor-beta family of regulatory factors, also known as growth and differentiation factor 8 (GDF8). The nucleotide sequence of human myostatin was determined in 40 individuals. The invariant promoter contains a consensus MyoD binding site, and the coding sequence contains five missense substitutions in conserved amino acid residues (A55T, K153R, E164K, P198A, and I225T). Two of these, A55T in exon 1 and K153R in exon 2, are polymorphic in the general population with significantly different allele frequencies in Caucasians and African Americans (P < 0.001). Neither of the common polymorphisms had a significant impact on muscle mass response to strength training in either Caucasians or African Americans, although skewed allele frequencies preclude detection of small effects. These allelic variants provide markers for examining association between the myostatin gene and interindividual variation in muscle mass and differences in loss of muscle mass with aging.

Amino Acid Substitution↗

PubMed1999

Strength training normalizes resting blood pressure in 65- to 73-year-old men and women with high normal blood pressure.

OBJECTIVE: To determine the effects of heavy resistance strength training (ST) on resting blood pressure (BP) in older men and women. DESIGN: Prospective intervention study. SETTING: University of Maryland Exercise Science Laboratory. PARTICIPANTS: Twenty-one sedentary, healthy older men (69 +/- 1 year, n = 11) and women (68 +/- 1 year, n = 10) served as subjects for the study. INTERVENTION: Six months of progressive whole body ST performed 3 days per week using Keiser K-300 air-powered resistance machines. MEASUREMENTS: One-repetition maximum (1 RM) strength was measured for seven different exercises before and after the ST program. Resting BP was measured on six separate occasions before and after ST for each subject. RESULTS: Substantial increases in 1 RM strength were observed for upper body (UB) and lower body (LB) muscle groups for men (UB: 215 vs 265 kg; LB: 694 vs 838 kg; P < .001) and women (UB: 128 vs 154 kg; LB: 441 vs 563 kg; P < .001). The ST program led to reductions in both systolic (131 +/- 2 vs 126 +/- 2 mm Hg, P < .010) and diastolic (79 +/- 2 vs 75 +/- 1 mm Hg, P < .010) BP. Systolic BP was reduced significantly in men (134 +/- 3 vs 127 +/- 2 mm Hg, P < .01) but not in women (128 +/- 3 vs 125 +/- 3 mm Hg, P < .01), whereas diastolic BP was reduced following training in both men (81 +/- 3 vs 77 +/- 1, mm Hg, P = .054) and women (78 +/- 2 vs 74 +/- 2 mm Hg, P = .055). CONCLUSIONS: Six months of heavy resistance ST may reduce resting BP in older persons. According to the latest guidelines from the Joint National Committee for the Detection, Evaluation, and Treatment of Hypertension, the changes in resting BP noted in the present study represent a shift from the high normal to the normal category.

Aged↗

PubMed1999

Muscle quality. I. Age-associated differences between arm and leg muscle groups.

To determine the differences between arm and leg muscle quality (MQ) across the adult life span in men and women, concentric (Con) and eccentric (Ecc) peak torque (PT) were measured in 703 subjects (364 men and 339 women, age range 19-93 yr) and appendicular skeletal muscle mass (MM) was determined in the arm and leg in a subgroup of 502 of these subjects (224 men and 278 women). Regression analysis showed that MQ, defined as PT per unit of MM, was significantly higher in the arm ( approximately 30%) than in the leg across age in both genders (P < 0.01). Arm and leg MQ declined at a similar rate with age in men, whereas leg MQ declined approximately 20% more than arm MQ with increasing age in women (P </= 0.01 and P < 0.05 for Con and Ecc PT, respectively). Moreover, the age-associated decrease in arm MQ was steeper in men than in women whether Con or Ecc PT was used (both P < 0.05). Arm MQ as determined by Con PT showed a linear age-related decline in men and women (28 and 20%, respectively, P < 0.001), whereas arm MQ as determined by Ecc PT showed a linear age-related decline in men (25%, P < 0.001) but not in women (not significant). In contrast, both genders exhibited an age-related quadratic decline in leg MQ as determined by Con PT ( approximately 40%) and Ecc PT ( approximately 25%; both P < 0.001), and the rate of decline was similar for men and women. Thus MQ is affected by age and gender, but the magnitude of this effect depends on the muscle group studied and the type of muscle action (Con vs. Ecc) used to assess strength.

Adult↗

PubMed1999

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

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.

Aged↗