Aim. The purpose of this study was to evaluate the relationship between weightlifting performance (snatch, clean and jerk, and total) and variables obtained from the isometric mid-thigh pull (IMTP). Methods. Twelve weightlifters, ranging from novice to advanced, performed the IMTP 10 days after a competition. Correlations were used to evaluate relationships between variables of the IMTP and absolute and scaled competition results. Results. Unsealed competition results correlated strongly with IRFD (0-200ms: r=0.567-0.645, 0-250ms: r=0.722-0.781) while results correlated weakly with Peak IRFD (5ms window, r=0.360-0.426). Absolute peak force values correlated very strongly with absolute values for the competition performance (r=0.830-0.838). Force at 100ms, 150ms, 200ms and 250ms also correlated strongly with competition results (r=0.643-0.647, r=0.605-0.636, r=0.714-0.732, r=0.801-0.804). Similar findings were noted for allometrically scaled values. Conclusion. Measures of average IRFD probably represent a more relevant variable to dynamic performance than does Peak IRFD (5ms). Maximum isometric strength also is likely to have a strong role in weightlifting performance.

The effects of supplementation of the leucine metabolite β-hydroxy-β- methylbutyrate (HMB) were examined in a resistance training study. Thirty- nine men and 36 women between the ages of 20-40 y were randomized to either a placebo (P) supplemented or HMB supplemented (3.0 g HMB/d) group in two gender cohorts. All subjects trained three times per week for 4 wk. In the HMB group, plasma creatine phosphokinase levels tended to be suppressed compared to the placebo group following the 4 wk of resistance training (HMB:174.4 ± 26.8 to 173.5 ± 17.0 U/L; P:155.0 ± 20.8 to 195.2 ± 23.5 U/L). There were no significant differences in strength gains based on prior training status or gender with HMB supplementation. The HMB group had a greater increase in upper body strength than the placebo group (HMB:7.5 ± 0.6 kg; P:5.2 ± 0.6 kg; P = 0.008). The HMB groups increased fat-free weight by 1.4 ± 0.2 kg and decreased percent fat by 1.1% ± 0.2% while the placebo groups increased fat-free weight by 0.9 ± 0.2 kg and decreased percent fat by 0.5% ± 0.2% (fat-free weight P = 0.08, percent fat P = 0.08, HMB compared to placebo). In summary, this is the first short-term study to investigate the roles of gender and training status on the effects of HMB supplementation on strength and body composition. This study showed, regardless of gender or training status, HMB may increase upper body strength and minimize muscle damage when combined with an exercise program.

Aim. The purpose of this study was to evaluate the relationship between weightlifting performance (snatch, clean and jerk, and total) and variables obtained from the isometric mid-thigh pull (IMTP). Methods. Twelve weightlifters, ranging from novice to advanced, performed the IMTP 10 days after a competition. Correlations were used to evaluate relationships between variables of the IMTP and absolute and scaled competition results. Results. Unsealed competition results correlated strongly with IRFD (0-200ms: r=0.567-0.645, 0-250ms: r=0.722-0.781) while results correlated weakly with Peak IRFD (5ms window, r=0.360-0.426). Absolute peak force values correlated very strongly with absolute values for the competition performance (r=0.830-0.838). Force at 100ms, 150ms, 200ms and 250ms also correlated strongly with competition results (r=0.643-0.647, r=0.605-0.636, r=0.714-0.732, r=0.801-0.804). Similar findings were noted for allometrically scaled values. Conclusion. Measures of average IRFD probably represent a more relevant variable to dynamic performance than does Peak IRFD (5ms). Maximum isometric strength also is likely to have a strong role in weightlifting performance.

Suchomel, TJ, Wright, GA, Kernozek, TW, and Kline, DE. Kinetic comparison of the power development between power clean variations. J Strength Cond Res 28(2): 350- 360, 2014-The purpose of this study was to compare the power production of the hang clean (HC), jump shrug (JS), and high pull (HP) when performed at different relative loads. Seventeen men with previous HC training experience, performed 3 repetitions each of the HC, JS, and HP at relative loads of 30, 45, 65, and 80% of their 1 repetition maximum (1RM) HC on a force platform over 3 different testing sessions. Peak power output (PPO), peak force (PF), and peak velocity (PV) of the lifter plus bar system during each repetition were compared. The JS produced a greater PPO, PF, and PV than both the HC (p > 0.001) and HP (p > 0.001). The HP also produced a greater PPO (p > 0.01) and PV (p > 0.001) than the HC. Peak power output, PF, and PV occurred at 45, 65, and 30% 1RM, respectively. Peak power output at 45% 1RM was greater than PPO at 65% (p = 0.043) and 80% 1RM (p = 0.004). Peak force at 30% was less than PF at 45% (p = 0.006), 65% (p > 0.001), and 80% 1RM (p = 0.003). Peak velocity at 30 and 45% was greater than PV at 65% (p > 0.001) and 80% 1RM (p > 0.001). Peak velocity at 65% 1RM was also greater than PV at 80% 1RM (p > 0.001). When designing resistance training programs, practitioners should consider implementing the JS and HP. To optimize PPO, loads of approximately 30 and 45% 1RM HC are recommended for the JS and HP, respectively.

The current manuscript is a translation of the Position statement on youth resistance training: the 2014 International Consensus. The original manuscript was adapted from the oficial position statement of the UK Strength and Conditioning Association on youth resistance training. It was subsequently reviewed and endorsed by leading professional organisations within the fields of sports medicine, exercise science and paediatrics. The authorship team for this article was selected from the fields of paediatric exercise science, paediatric medicine, physical education, strength and conditioning and sports medicine.

The purpose of this investigation was to examine the relationships between measures ofmaximal isometric force (peak force [PF]), rate of force development (RFD), vertical jump performance (VJ) and 1-repetition maximum (1RM) strength in recreationally trained men. The subjects in this study were 26 men ([mean ± SD]: age 22± 1 years; height 175 ± 7 cm; mass 90 ± 10 kg). They were tested for PF using the isometric midthigh pull exercise. The 1RM for the squat and bench press exercise were determined as a measure of dynamic strength. Explosive strength was measured as RFD from the isometric force-time curve. Correlations between the variables were calculated using Pearson product moment correlation coefficient. There was a nearly perfect correlation between measures of PF and 1RM squat (r = 0.97, p < 0.05) and 1RM bench press (r = 0.99, p < 0.05). The correlations were very strong between VJ and PF (r = 0.72, p < 0.05) and 1RM bench press (r = 0.70, p < 0.05). There were also strong correlations between VJ and 1RM squat (r = 0.69, p < 0.05). There were no significant correlations with RFD. The results showed that isometric maximum strength determined during the isometric midthigh pull test correlated well with 1RM and VJ testing. However, RFD measured during the same test did not appear to correlate as well with other measures. The isometric midthigh pull provides an efficient method for assessing strength in recreationally trained individuals. Practioners wishing to obtain performance data related to maximum strength may wish to consider isometric testing as a less time intensive method of testing.

The purpose of this research note was to examine whether relationships existed between anthropometrics (body mass, body fat percentage [BF%], and femur length) and descriptive characteristics (age and sex) with repetitions performed to failure at 70% of 1 repetition maximum (1RM) in the back squat. Fifty-eight subjects (males = 43, females = 15; age: 23 ± 3 years, training age: 5.5 ± 2.5 years, body mass: 80.65 ± 16.34 kg, BF%: 10.98 ± 3.53%, and femur length: 47.1 ± 2.6 cm) completed a 1RM squat followed by one set to failure at 70% of 1RM. Total repetitions performed at 70% of 1RM were 14 ± 4 (range: 6–26). Bivariate correlations showed significant inverse relationships between body mass (r = -0.352, p = 0.003), BF% (r = -0.278, p = 0.014), and femur length (r = -0.265, p = 0.019), with repetitions performed. No significant relationships existed between age and sex (p > 0.05), with repetitions performed. All these variables entered into a standard multivariate regression. The model R2 was 0.200, and body mass had the largest influence (p = 0.057) because relative importance analysis demonstrated body mass to contribute to 43.87% of the variance (of the R2) in repetitions performed. No other variable was significant or approached significance (p > 0.05). Our results reveal that body mass, BF%, and femur length all are inversely related to repetitions performed at 70% of 1RM in the back squat.

No description available.

One of the age-related changes associated with normal aging is the inability to maintain normal blood pressure homeostasis, a common clinical condition known as orthostatic intolerance. There are little data on the effects of strength training in healthy adults and orthostatic intolerance, and only one study on strength training and elderly adults diagnosed with orthostatic intolerance. Therefore, the purpose of the present study was to evaluate the effects of resistance training on the cardiovascular respones of elderly individuals during an orthostatic challenge. Thirteen subjects were assigned to either a resistance (RES; n=7; 66±5 yrs.) or a control (CON; n=6; 71±6 yrs.) group. During the 12-week treatment period, the RES trained 2x/wk, while the CON was asked not to change their normal lifestyles. The resistance training consisted of 3 sets of 8-12 repetitions using 12 machines at approximately 22% to 57% of 1RM. Before and after the training and control period, subjects were tested using a 70 degree head-up tilt. Tilt consisted of 30 minutes of supine rest while heart rate(HR) was recorded every minute and blood pressure (BP) was taken every 5 minutes. After the rest period, subjects were tilted to 70 degrees for 30 minutes unless subjects experienced presyncopal symptoms. During the tilt period, HR and BP were recorded every minute. After the tilt, subjects were placed in a supine position for 15 minutes of recovery, HR was taken every minute, and BP was taken every 5 minutes. A 2X2X8(test X group X time) Repeated Measures Analysis of Variance was used to analyze data. Significance was accepted at p ≤ 0.05. After the 12 weeks of training, the RES significantly increased upper (46±24 to 55±29kg) and lower (62±20 to 80±31kg) body strength while the CON showed no changes. Body composition measurements by DEXA showed lean mass to increase significantly (50.5±12.9 to 52.7±13.1kg) for the RES group, while the CON showed no changes. Of the 13 subjects only 9 subjects completed the pre and post tilt tests. Of the 9 completing both tilt periods, there were no significant differences between groups for any of the dependent measures of HR, systolic blood pressure, diastolic blood pressure and mean arterial pressure. In conclusion, this study demonstrated that a resistance training program was well tolerated and improved strength and lean mass in the RES. However, training did not help these individuals improve cardiovascular responses to an orthostatic challenge.

Recent evidence suggests that declining bone mineral density (BMD) in males is related to declining circulating estrogens. The majority of endogenous plasma estrogens in males result from peripheral aromatization of plasma androgens. Thus, it was hypothesized that dietary supplementation with an aromatizable androgen (androstenedione) may stimulate increases in BMD. BMD (measured by dual energy x-ray absorptiometry) and biochemical markers of bone turnover (1, 25 OH2 Vitamin D, calcitonin, deoxypyrodinoline, and parathyroid hormone) were assessed before and after 12 weeks of dietary androstenedione supplementation (200 mg/d). Twenty-four volunteers were randomized into either an androstenedione supplementation or placebo groups. Study volunteers also performed high intensity resistance training (RT) during the treatment period. Androstenedione supplementation significantly increased plasma estradiol-17β levels by 82%. However, the increase in estradiol-17β did not impact bone turnover. The RT regimen did stimulate significant, local increases in BMD. Spine BMD was significantly increased by 6% for both treatment groups.