Water-based continuous and interval training in older women: Cardiorespiratory and neuromuscular outcomes (WATER study)

The purpose of this study was to investigate the effects of two water-based aerobic programs on cardiorespiratory and neuromuscular outcomes in older women. Forty-one women (60 to 75 years old) volunteered to participate in the study. Participants were randomized into a water-based continuous (CTG; n = 21; 63.9 ± 2.5 years) or an interval (ITG; n = 20; 64.8 ± 3.6 years) aerobic training group. Both training programs were performed for 12 weeks (45-min sessions twice a week), with exercise intensity based on rating of perceived exertion (Borg's RPE 6–20 Scale). Pre and post training assessments of cardiorespiratory and neuromuscular outcomes were performed. Data analyses were conducted using Generalized Estimating Equations and Bonferroni post-hoc test (α = 0.05). After the intervention, the CTG and the ITG displayed similar improvements in time to exhaustion (8% vs. 11%), peak oxygen uptake (9% vs. 7%), maximal dynamic knee extension strength (5% vs. 6%), dynamic muscular endurance of knee extensors (10% vs. 11%), maximal vastus lateralis electromyographic signal amplitude (13% vs. 35%), as well as an increase in muscle thickness (5% vs. 6%) and decrease in muscle echo intensity (−2% vs. −3%) of the quadriceps femoris. In conclusion, older women benefited from water-based exercise training prescribed based on participants' RPE, with both the interval and the continuous training programs resulting in similar increases in the cardiorespiratory and neuromuscular parameters.