Water-based exercises in postmenopausal women: Vertical ground reaction force and oxygen uptake responses

Abstract

The purpose of the present study was to analyse vertical ground reaction force (Fz) and oxygen uptake (VO₂) responses in six different water-based exercises performed at different cadences by postmenopausal women. Twelve postmenopausal women (57.3 ± 2.6 years, 158.1 ± 6.9 cm, 69.1 ± 10.9 kg) voluntarily took part in the study. Participants completed six sessions corresponding to maximal tests for each water-based exercise. Then, two sessions were performed for the experimental protocols, which comprised the performance of three exercises at three cadences (80, 100 and 120 b min⁻¹), with Fz and VO₂ measurements. Peak (Fz_peak) and impulse of Fz were determined. In addition, VO₂ percentages relative to maximal VO₂ (VO_2max) values obtained in each maximal test were expressed as %VO_2max. Data were analysed using two-way ANOVA with repeated measures (α = 0.05). As results, significant differences were found in Fz_peak and impulse between the water-based exercises, with similar VO₂ and %VO_2max values between them for each cadence. In addition, with the increasing cadence, Fz_peak (0.20–0.80 BW), VO₂ (5.3–9.4 ml kg⁻¹ min⁻¹) and %VO_2max (32.1–57.6%) values increased, while impulse (0.20–0.07 N.s/BW) values were reduced. Therefore, for a same physiological intensity, postmenopausal women experience different Fz loads during different water-based exercises.

Keywords:

• Kinetics
• cardiorespiratory
• aquatic exercises

Acknowledgments

The authors are grateful to all the individuals who participated in this research and made this project possible.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work was supported by the Conselho Nacional de Desenvolvimento Científico e Tecnológico, Brazil. [Grant number 481778/2011-0].