While the optimal frequency of HIIT remains unresolved in both young and ageing cohorts, there are currently no data available regarding recovery rates from HIIT in older participants. PURPOSE: To compare recovery time, from a single HIIT session, in older and younger men. METHODS: Following approval from the Institutional Ethics Committee at the University of the West of Scotland, 10 older (age=63±3.4yrs; height=1.74±0.04m mass=79.58±9.2kg) and 10 younger (21±2yrs; height 1.77±0.05; mass=81.0±10.7kg) apparently healthy males provided written informed consent to participate in the study. The study employed a parallel crossover RCT design. All participants were initially evaluated for PPO (Baseline) and performed a single HIIT session on the same day and were randomly assigned to either 3 days (3DR) or 5 days (5DR) of recovery before PPO reassessment. Seven days following the PPO reassessment, participants undertook a second, identical HIIT session, and crossed over to the opposing arm of the trial. PPO was assessed on a Wattbike Pro (Wattbike Ltd Nottingham, UK) cycle ergometer using a test that has been validated against PPO achieved during a standard Wingate test and described previously. HIIT sessions consisted of 6 x 30 s sprints at 50% of PPO determined at Baseline. Each 30 s effort was interspersed with 3 mins of active recovery against a low (0-50W) resistance and at a self-selected cadence. RESULTS: There was a significant effect of recovery time (P<0.01) and of age group (P<0.01) and a significant interaction between the two (P<0.01). Between groups, the younger group generated greater PPO at all-time points compared with the older cohort (Baseline= 852±102 versus 1171±247W, 3DR= 814±88 versus 1181±256W and 5DR= 861±104 versus 1182±259W for old versus young respectively; all P<0.01). Compared with baseline, the older group experienced a significant reduction in PPO at 3DR (P<0.01), which was not evident at 5DR (P>0.05), whereas PPO remained unchanged in the young group between baseline and 3DR and 5DR (P>0.05 for all comparisons). CONCLUSION: Older men require longer than 3 days to recover from a single bout of HIIT and the present study promotes the exercising of caution when prescribing standard HIIT regimens (3.session.week-1) to older persons.
|Journal||Medicine & Science in Sports & Exercise|
|Publication status||Published - May 2015|