Gender differences in anaerobic power of the arms and legs--a scaling issue.

PURPOSE: Physiological variables must be scaled for body size differences to permit meaningful comparisons between groups. Using allometric scaling, this study compared the anaerobic performance, using both arms and legs, of men and women. Ten active male and 10 active female subjects performed the leg cycling and arm cranking in a 30-s all-out Wingate test (WAnT). Regional measurements of the legs, gluteal area, arms, and torso taken using dual-energy x-ray absorptiometry (DXA) served as indicators of lower body active musculature (LBAMM) and upper body (UBAMM) active musculature. RESULTS: Body mass (BM) was the best predictor (i.e., r = 0.93-0.96) for peak power (PP) and mean power (MP) generated from sprint cycling and arm cranking. Sex differences for leg and arm power (i.e., PP and MP) were identified in absolute terms and then expressed in ratio to BM(1.0). When the same data were allometrically scaled to BM and expressed as power function ratios (Power;BM(b)), the sex differences in PP and MP for sprint cycling were nullified (female:male ratio x 100: 100-103%), but remained for arm cranking (female:male power ratio x 100: 69-84%). CONCLUSIONS: These results confirmed that anaerobic power of the upper body and lower body were best normalized to BM and, when statistically appropriate methods were used to take into account differences in BM, PP, and MP generated from sprint cycling were similar for both men and women. In contrast, after allometric scaling for BM, men remained more powerful than women for the supramaximal arm cranking task. Qualitative differences in the upper body musculature between men and women are speculated to account for the more powerful performance of men, but confirmatory evidence using noninvasive techniques is warranted.

Maximal leg-strength training improves cycling economy in previously untrained men.

PURPOSE: This study examined cycling economy before and after 8 wk of maximal leg-strength training. METHODS: Seven previously untrained males (25 +/- 2 yr) performed leg-strength training 3 d.wk(-1) for 8 wk using four sets of five repetitions at 85% of one repetition maximum (1RM). Body mass, lean-leg muscle mass (LLM), percentage of body fat, and leg strength (1RM) were measured at 0, 4, and 8 wk of training. Cycling economy was calculated as the deltaVO2/deltaWR (change in the O2 cost of exercise divided by the change in the power between two different power outputs). RESULTS: There were significant increases in LLM and 1RM from 0 to 4 wk of training (LLM: 25.8 +/- 0.7 to 27.2 +/- 0.8 kg; 1RM: 138 +/- 9 to 215 +/- 9 kg). From 4 to 8 wk of training, 1RM continued to increase significantly (215 +/- 9 to 266 +/- 8 kg) with no further change observed in LLM. Peak power during incremental cycling increased significantly (305 +/- 14 to 315 +/- 16 W), whereas the power output achieved at the gas-exchange threshold (GET) remained unchanged. Peak O2 uptake and the O2 uptake achieved at the GET also remained unchanged following training. Cycling economy improved significantly when the power output was increased from below the GET to above the GET but not for power outputs below the GET. CONCLUSION: Maximal leg-strength training improves cycling economy in previously untrained subjects. Increases in leg strength during the final 4 wk of training with unchanged LLM suggest that neural adaptations were present.

Evaluation of anthropometric, physiological, and skill-related tests for talent identification in female field hockey.

The purpose of the present study was to develop an effective testing battery for female field hockey by using anthropometric, physiological, and skill-related tests to distinguish between regional representative (Rep, n = 35) and local club level (Club, n = 39) female field hockey players. Rep players were significantly leaner and recorded faster times for the 10-m and 40-m sprints as well as the Illinois Agility Run (with and without dribbling a hockey ball). Rep players also had greater aerobic and lower body muscular power and were more accurate in the shooting accuracy test, p < 0.05. No significant differences between groups were evident for height, body mass, speed decrement in 6 x 40-m repeated sprints, handgrip strength, or pushing speed. These results indicate that %BF, sprinting speed, agility, dribbling control, aerobic and muscular power, and shooting accuracy can distinguish between female field hockey players of varying standards. Therefore talent identification programs for female field hockey should include assessments of these physical parameters.

Increases in maximal accumulated oxygen deficit after high-intensity interval training are not gender dependent.

Gender differences in maximal accumulated oxygen deficit (MAOD) were examined before and after 4 and 8 wk of high-intensity interval training. Untrained men (n = 7) and women (n = 7) cycled at 120% of pretraining peak oxygen uptake (VO2 peak) to exhaustion (MAOD test) pre-, mid-, and posttraining. A posttraining timed test was also completed at the MAOD test power output, but this test was stopped at the time to exhaustion achieved during the pretraining MAOD test. The 14.3 +/- 5.2% increase in MAOD observed in men after 4 wk of training was not different from the 14.0 +/- 3.0% increase seen in women (P > 0.05). MAOD increased by a further 6.6 +/- 1.9% in men, and this change was not different from the additional 5.1 +/- 2.3% increase observed in women after the final 4 wk of training. VO2 peak measured during incremental cycling increased significantly (P < 0.01) in male but not in female subjects after 8 wk of training. Moreover, the accumulated oxygen (AO2) uptake was higher in men during the posttraining timed test compared with the pretraining MAOD test (P < 0.01). In contrast, the AO2 uptake was unchanged from pre- to posttraining in female subjects. The increase in MAOD with training was not different between men and women, suggesting an enhanced ability to produce ATP anaerobically in both groups. However, the increase in VO2 peak and AO2 uptake obtained in male subjects after training indicates improved oxidative metabolism in men but not in women. We conclude that there are basic gender differences that may predispose men and women to specific metabolic adaptations after a period of intense interval training.