The present study examined the effects of a 6-week whole-body vibration training (WBVT) regimen on heart rate variability (HRV) and body composition in obese Hispanic postmenopausal women. Participants were randomly assigned to either WBVT (n = 13) or a nonexercising control group (n = 14). HRV and body composition were measured before and after 6 weeks. There was a significant group by time interaction (P < .05) for heart rate, sympathovagal balance, and body fat percentage (BF%) such that all significantly decreased (P < .05); and R-R intervals significantly increased (P < .05) following WBVT compared to no changes after control. The changes in sympathovagal balance were correlated with changes in BF% (r = .63, P < .05). Our findings indicate that WBVT improves HRV and BF% in obese Hispanic postmenopausal women. The improvement in BF% partially explained the decrease in sympathovagal balance. Since obese and older individuals are at increased risk of developing cardiovascular diseases, they could potentially benefit from WBVT.
Gregory Severino, Marcos Sanchez-Gonzalez, Michelle Walters-Edwards, Michael Nordvall, Oksana Chernykh, Jason Adames and Alexei Wong
Louise C. Mâsse, Janet E. Fulton, Kathleen B. Watson, Susan Tortolero, Harold W. Kohl III, Michael C. Meyers, Steven N. Blair and William W. Wong
The purpose of this study was to compare the validity of 2 physical activity questionnaire formats—one that lists activities (Checklist questionnaire) and one that assesses overall activities (Global questionnaire) by domain.
Two questionnaire formats were validated among 260 African-American and Hispanic women (age 40–70) using 3 validation standards: 1) accelerometers to validate activities of ambulation; 2) diaries to validate physical activity domains (occupation, household, exercise, yard, family, volunteer/church work, and transportation); and 3) doubly-labeled water to validate physical activity energy expenditure (DLW-PAEE).
The proportion of total variance explained by the Checklist questionnaire was 38.4% with diaries, 9.0% with accelerometers, and 6.4% with DLW-PAEE. The Global questionnaire explained 17.6% of the total variance with diaries and about 5% with both accelerometers and with DLW-PAEE. Overall, associations with the 3 validation standards were slightly better with the Checklist questionnaire. However, agreement with DLW-PAEE was poor with both formats and the Checklist format resulted in greater overestimation. Validity results also indicated the Checklist format was better suited to recall household, family, and transportation activities.
Overall, the Checklist format had slightly better measurement properties than the Global format. Both questionnaire formats are better suited to rank individuals.
Adam D. Osmond, Dean J. Directo, Marcus L. Elam, Gabriela Juache, Vince C. Kreipke, Desiree E. Saralegui, Robert Wildman, Michael Wong and Edward Jo
Context: Of the 3 branched-chain amino acids (BCAA), leucine has arguably received the most attribution for the role of BCAA supplementation in alleviating symptoms of exercise-induced muscle damage and facilitation of acute performance recovery. Purpose: To examine whether enrichment of a standard BCAA supplement with additional leucine or a standalone leucine (LEU) supplement differentially affects exercise-induced muscle damage and performance recovery compared with a standard BCAA supplement. Methods: A total of 22 recreationally active male and female subjects were recruited and assigned to consume a BCAA, leucine-enriched BCAA (LBCAA), or LEU supplement for 11 d. On the eighth day, subjects performed eccentric-based resistance exercise (ECRE). Lower-body mean average and peak power, plasma creatine kinase, soreness, and pain threshold were measured before and 24, 48, and 72 h after ECRE. Results: LEU showed decreased mean average power (P = .02) and mean peak power (P = .01) from baseline to 48 h post-ECRE, whereas LBCAA and BCAA only trended toward a reduction at 24 hours post-ECRE. At 48 h post-ECRE, BCAA showed greater recovery of mean peak power than LEU (P = .04). At 24 h post-ECRE, LEU demonstrated a greater increase in plasma creatine kinase from baseline than BCAA (P = .04). Area under the curve for creatine kinase was greater in LEU than BCAA (P = .02), whereas BCAA and LBCAA did not differ. Only LEU demonstrated increased soreness during rest and under muscular tension at 24 and 48 h post-ECRE (P < .05). Conclusions: LBCAA failed to afford any advantages over a standard BCAA supplement for postexercise muscle recovery, whereas a LEU supplement was comparatively ineffective.