increase lean body mass and basal metabolism, jointly assisting with weight control). 3 Additionally, aerobic and resistance exercise have several unique health outcomes (eg, greater maximum oxygen uptake adaptations from aerobic training vs greater muscular strength and endurance adaptations from
Meghan K. Edwards and Paul D. Loprinzi
Paulo Sugihara Junior, Alex S. Ribeiro, Hellen C.G. Nabuco, Rodrigo R. Fernandes, Crisieli M. Tomeleri, Paolo M. Cunha, Danielle Venturini, Décio S. Barbosa, Brad J. Schoenfeld and Edilson S. Cyrino
effects of sarcopenia and dynapenia, as this population generally possesses lower levels of muscular strength and SMM compared with men ( Brady et al., 2014 ; Hughes et al., 2001 ). Resistance training (RT) is a well-recognized method of exercise for increasing muscular strength and hypertrophy, and thus
Paul D. Loprinzi and Jeremy P. Loenneke
Leukocyte telomere length (LTL) shortening is characteristic of aging and is associated with morbidity and mortality, independent of age. Research demonstrates that lower extremity muscular strength is associated with mobility, morbidity and mortality; however, no study, to our knowledge, had examined the association between lower extremity muscular strength and LTL, which was the purpose of this brief study.
Data from the 1999–2002 NHANES was used (N = 2410; 50–85 years). Peak isokinetic knee extensor strength (IKES) was objectively measured with LTL assessed from a blood sample.
After adjustments, for every 50 N increase in IKES, participants had a 9% reduced odds (P = .04) of being in the 1st (vs. 4th) LTL quartile.
Lower extremity muscular strength is associated with LTL, suggesting a possible mechanism through which lower extremity muscular strength may be associated with morbidity and mortality.
Jeffrey A. Woods, Russell R. Pate and Maria L. Burgess
Field tests of upper body muscular strength and endurance (UBMSE) are often administered to children, but little is known about the determinants of performance on these tests. Therefore the purpose of this investigation was to examine potential determinants of performance on several common field tests of UBMSE including pull-ups, flexed-arm hang, push-ups, and two types of modified pull-ups. Subjects were 56 girls and 38 boys, ages 9 to 11 years. Potential determinants assessed were age, height, weight, gender, % fat, physical activity, and laboratory measures of muscular strength and endurance. Multiple regression analysis revealed that the laboratory measures of UBMSE failed to account for significant fractions of variance in performance on four of the five tests. However, % fat was significantly associated with performance on four of five tests. These results indicate that factors other than muscular strength and endurance account for most of the variance in performance, and that % fat appears to be a particularly important determinant of performance.
Michael J. Ormsbee, Brandon D. Willingham, Tasha Marchant, Teresa L. Binkley, Bonny L. Specker and Matthew D. Vukovich
.7** , * 36.5 ± 0.9** 44.1 ± 0.8** , * male 44.2 ± 0.9 44.6 ± 0.8 47.4 ± 1.0** 48.6 ± 1.0** 48.1 ± 1.0** 48.9 ± 0.9** Note . Values are reported as mean ± SE . VO 2 peak = peak oxygen consumption. * p = .06 between control and protein for females. ** p < .05 compared with baseline. Muscular Strength The
Troy Blackburn, Kevin M. Guskiewicz, Meredith A. Petschauer and William E. Prentice
To determine whether proprioception or muscular strength is the dominant factor in balance and joint stability and define what type of ankle rehabilitation is most effective for these purposes.
The University of North Carolina Sports Medicine Research Laboratory.
Thirty-two healthy volunteers free of head injury, dominant leg injury, and vestibular deficits.
Subjects were divided into control, strength-training, proprioceptive-training, and strength-proprioception combination training groups. Balance was assessed before and after 6-week training programs.
Static, semidynamic, and dynamic balance were assessed.
Subjects showed no improvement for static balance but improved significantly for semidynamic (P = .038) and dynamic (P = .002) balance. No significant differences were observed between groups.
Enhancement of proprioception and muscular strength are equally effective in promoting joint stability and balance maintenance. In addition, no 1 type of training program is superior to another for these purposes.
Rachel A. Hildebrand, Bridget Miller, Aric Warren, Deana Hildebrand and Brenda J. Smith
Increasing evidence indicates that compromised vitamin D status, as indicated by serum 25-hydroxyvitamin D (25-OH D), is associated with decreased muscle function. The purpose of this study was to determine the vitamin D status of collegiate athletes residing in the southern U.S. and its effects on muscular strength and anaerobic power. Collegiate athletes (n = 103) from three separate NCAA athletic programs were recruited for the study. Anthropometrics, vitamin D and calcium intake, and sun exposure data were collected along with serum 25-OH D and physical performance measures (Vertical Jump Test, Shuttle Run Test, Triple Hop for Distance Test and the 1 Repetition Maximum Squat Test) to determine the influence of vitamin D status on muscular strength and anaerobic power. Approximately 68% of the study participants were vitamin D adequate (>75 nmol/L), whereas 23% were insufficient (75–50 nmol/L) and 9%, predominantly non-Caucasian athletes, were deficient (<50 nmol/L). Athletes who had lower vitamin D status had reduced performance scores (p < .01) with odds ratios of 0.85 on the Vertical Jump Test, 0.82 on the Shuttle Run Test, 0.28 on the Triple Hop for Distance Test, and 0.23 on the 1 RM Squat Test. These findings demonstrate that even NCAA athletes living in the southern US are at risk for vitamin D insufficiency and deficiency and that maintaining adequate vitamin D status may be important for these athletes to optimize their muscular strength and power.
Andrew C. Fry, Carol C. Irwin, Justin X. Nicoll and David E. Ferebee
To determine absolute and relative (adjusted for body mass) strength, mean power, and mean velocity for upper and lower body resistance exercises, forty-seven young boys and girls participated in maximal strength testing. Healthy young boys and girls, ages 3- to 7-years old, were tested for one-repetition maximum (1-RM) strength, and 70% of 1-RM to determine mean power and mean velocity on the chest press and leg press exercises. Adult weight machines were modified to accommodate the smaller size and lower strength levels of the children. A 2 × 4 (sex × age) ANOVA was used to determine age and sex differences in performance. No interaction or sex differences were observed for any variable at any age. 1-RM strength, mean power, and mean velocity significantly increased across ages (p ≤ .05). When adjusted for body mass, the changes were insignificant, with one exception. Relative mean power for the bench press increased with age. Data indicated children from 3-7 years of age are capable of performing strength and power tests, but may require more attempts at maximal loads compared with adults. It appears that muscular strength and velocity during this stage of development are primarily dependent on increasing body mass, whereas power is influenced by additional variable(s).
Luiz Henrique Palucci Vieira, Felipe de Souza Serenza, Vitor Luiz de Andrade, Lucas de Paula Oliveira, Fábio Pamplona Mariano, Juliana Exel Santana and Paulo Roberto Pereira Santiago
The aims of the current study were to analyze a kick from 10 m in a futsal context and the parameters of muscular strength using an isokinetic dynamometer in a laboratory environment, performed with the dominant (DL) and nondominant lower limbs (NDL). Seventeen professional elite players participated. Kicking performance was evaluated from the second penalty mark. Next, athletes completed a strength evaluation with an isokinetic dynamometer at speeds of 60°⋅s–1, 180°⋅s–1, and 300°⋅s–1. Significant differences were observed for hip (15.64 ± 3.44; 13.97 ± 2.62), ankle (63.19 ± 8.90; 52.55 ± 8.72), foot (82.31 ± 7.93; 68.41 ± 7.85), and ball (99.74 ± 8.45; 88.31 ± 7.93) speeds (km⋅h–1), and average power at 180°⋅s–1 (325.59 ± 40.47; 315.79 ± 39.49 W), but not for accuracy (1.33 ± 0.57; 1.66 ± 0.77 m) between the DL and NDL, respectively. Few moderate correlations were observed in the DL (r = .54–.64) or NDL (r = .53–.55) between the kinematic variables of kick and muscular strength parameters (P < .05). We conclude that highly trained players present asymmetries in kicking motion; however, the imbalance in muscular strength is very small. We recommend that specific court tests be conducted to reliably characterize kicking performance in futsal. Success in kicking seems to be too variable and complex to be totally predicted only by joints, foot and ball speed, and lower limb muscular strength parameters.
Gordon Sleivert, Val Burke, Craig Palmer, Alan Walmsley, David Gerrard, Stephen Haines and Roger Littlejohn
To determine the effects of deer antler velvet on maximal aerobic performance and the trainability of muscular strength and endurance, 38 active males were randomly assigned in a double-blind fashion to either deer antler velvet extract (n = 12), powder (n = 13), or placebo groups (n = 13). Subjects were tested prior to beginning supplementation and a 10-week strength program, and immediately post-training. All subjects were measured for circulating levels of testosterone, insulin-like growth factor, erythropoietin, red cell mass, plasma volume, and total blood volume. Additionally, muscular strength, endurance, and VO2max were determined. All groups improved 6 RM strength equivalently (41 ± 26%, p < .001), but there was a greater increase in isokinetic knee extensor strength (30 ± 21% vs. 13 ± 15%, p = .04) and endurance (21 ± 19% vs. 7 ± 12%, p = .02) in the powder compared to placebo group. There were no endocrine, red cell mass or VO2max changes in any group. These findings do not support an erythropoetic or aerobic ergogenic effect of deer antler velvet. Further, the inconsistent findings regarding the effects of deer antler velvet powder supplementation on the development of strength suggests that further work is required to test the robustness of the observation that this supplement enhances the strength training response and to ensure this observation is not a type I error.