Effectiveness Of A 6-month Water-based Exercise In Preventing Physical Activity Decline In Elderly Subjects

ABSTRACT: The development and progression of sarcopenia is a complex and multi-factorial process. A growing body of evidence indicates that physical activity in elderly can slow the loss of skeletal muscle and function. Among exercise modalities, water-based protocols are suggested for subjects in whom a lower joint stress is recommended, however, limited data are available about their actual effects in maintaining muscle mass and physical fitness. PURPOSE: To determine the effect in body composition, strength and flexibility of a physical activity program performed in thermal water respect to a similar land-based protocol. METHODS: 40 subjects (N=20 Male, N=20 Female) were recruited (age = 71.7 yrs, BMI = 26.2 kg/m2), and randomly allocated to two groups: Aquatic Group (AG) and Land Group (LG). During the 6 months, subjects followed a twice-a-week exercise intervention. Exercise intensity was monitored using Borg's Scale and heart rate. Functional evaluation was performed before and after the exercise protocols. Body composition was assessed by bioimpedance analysis, strength by handgrip dynamometry, as well as isotonic knee extension. Physical performance was also assessed using the Senior Fitness Test. Statistical analysis was made using ANOVA for repeated measures. Because of healthy reasons or lack of interest in participation, 6 subjects dropped out from the study (2 in AG vs 4 in LG). RESULTS: AG showed a significant reduction in body weight (69.7±13.3 to 68.8±13.6 kg, p<0.05) and fat mass (21.9±5.8 to 20.9±5.6 kg, p<0.05), while LG did not. AG and LG improved both in 8-foot up & go (5.6±1.2 to 4.9±0.7, p<0.05 and 6.1±2.1 to 5.3±2.1 seconds, p<0.05) and modified sit & reach tests (AG 2.8±6.7 to 12.8±6.7 cm in right leg, p<0.05; AG 3.5±8.0 to 13.33±7 cm left leg, p<0.05; LG 5.0±12.6 to 13.4±11.5 cm in right leg, p<0.05; LG 5.6±12.1 to 13.7±11.7 cm in left leg, p<0.05). Handgrip strength proved a significant increase only in LG (18.7±8.4 to 23.5±9.1 kg, p<0.05). The other tests demonstrated a similar, not significant, positive trend. CONCLUSION: Both land and water-based activities seem beneficial in improving dynamic balance and flexibility. Strength values appear maintained. Further analysis will allow evaluation of muscle mass by peripheral quantitative computed tomography and the comparison with a control group.