Short-term Detraining Effects On Cardiorespiratory Fitness And Body Composition In Trained Older Adults: 3570 Board #258 June 1 9:30 AM - 11:00 AM

An interruption in the training routine may have deleterious effects on cardiorespiratory fitness (CRF) and body composition. Particularly the decline that can occur in the phase-angle (PhA), derived from the tangent value of the ratio of reactance versus electric resistance from bio-impedance analysis (BIA), may be of concern, as it is a predictive marker for cellular integrity, sarcopenia, muscular function, and frailty in older adults. PURPOSE: To determine the effects of 2-week detraining period on CRF and body composition (including PhA) in older trained adults. METHODS: A total of 11 older adults (4 females) aged ≥ 65 years were assessed at baseline and follow-up for CRF and body composition in the early morning in fasting condition. Fat-free mass (%FFM), fat mass (%FM), android fat mass (%AFM), and gynoide fat mass (%GFM) were estimated with dual-energy X-ray absorptiometry (DXA) and PhA was assessed with BIA. CRF was evaluated with a breath-by-breath gas analyser system (Quark RMR, Cosmed) with a modified Bruce protocol. During the 15-day detraining period, participants were instructed to refrain from structured and supervised exercise sessions. One - way repeated measures ANOVA were performed and all analyses were adjusted for sex. RESULTS: The interruption of structured and supervised exercise sessions for 15-days resulted in declines in PhA (5.5%; p-value=0.037). No differences were found for weight (p=0.662), body mass index (p=0.631), %FM (p=0.953), %FFM (p=0.455), %AFM (p=0.138), %GFM (p=0.300), and CRF (p=0.618). CONCLUSIONS: A short-term detraining period of 2-weeks resulted in detrimental changes in PhA, suggesting a decline in the integrity of body cells, but no changes in the remaining body composition outcomes or CRF. These results highlight the importance of maintaining structured exercise sessions in older adults in order to preserve body cell integrity.