Purpose: To examine the effects of a 6-month whole-body vibration (WBV) training on lower-body strength (LBS), lower-body power (LBP), and swimming performance in adolescent trained swimmers. Methods: Thirty-seven swimmers (23 males and 14 females; 14.8 [1.3] y) were randomly assigned to the WBV (n = 20) or the control group (n = 17). Isometric LBS (knee extension and half squat) and LBP (vertical and horizontal jumps and 30-m sprint) tests were performed before and after the intervention period. Swimming performance times in 100 m were collected from official competitions. As time × sex interaction was not found for any variable (P > .05), males and females were analyzed as a whole. Results: Within-group analyses showed a most likely beneficial moderate effect of WBV on isometric knee extension (effect size [ES] = 0.63), 30-m sprint test (ES = 0.62), and 100-m performance (ES = 0.25), although these were corresponded with comparable small to moderate effects in the control group (ES = 0.73, 0.71, and 0.20, respectively). The control group obtained a small possibly beneficial effect of swimming-only training on vertical jump performance, whereas no effect was observed in the WBV group. Unclear effects were observed for the rest of the variables assessed. Between-group analyses revealed unclear effects of WBV training when compared with the control condition in all studied variables. Conclusions: There is no current evidence to support the use of WBV training, and therefore, coaches and sports specialists should select other methods of training when the aim is to increase LBS, LBP, or swimming performance.
Borja Muniz-Pardos, Alejandro Gómez-Bruton, Ángel Matute-Llorente, Alex González-Agüero, Alba Gómez-Cabello, José A. Casajús, and Germán Vicente-Rodríguez
Alba Gómez-Cabello, Germán Vicente-Rodríguez, Isabel Navarro-Vera, Diana Martinez-Redondo, Carmen Díez-Sánchez, and José Antonio Casajús
The aim of this study was to provide information about the relationship of bone mineral content (BMC) and density (BMD) with some physical-fitness-related variables in a sample of women with fibromyalgia (FM) and age-matched women without FM. Twenty-eight women clinically diagnosed with FM (age 51.1 ± 8.4 yr, M ± SD) and 22 age-matched controls participated in the study. Whole-body BMC and BMD, lean mass, handgrip strength, quadriceps strength, and cardiovascular fitness were measured in all participants. The association between physical-fitness variables and bone-related variables was tested by linear regression controlling for body weight as a possible confounder. There were no differences in BMC or BMD between groups. Women with FM had lower values of handgrip strength, quadriceps strength, and VO2peak than the control group. Handgrip strength and aerobic capacity were associated with BMC and BMD and quadriceps strength was associated with BMD in women with FM; however, only VO2peak was associated with BMC in the group of women without FM. Bone mass of women with FM may be more susceptible to changes in physical fitness than that of the women without fibromyalgia.