Efficacy of High-Intensity Resistance and Sprint Interval Training in Older Adults

Abstract

High-intensity interval training has been shown to improve health/fitness factors in adults. Evidence is limited in older adults with chronic disease and increased risk for exercise-related complications and for resistance training modes. PURPOSE: Assess the efficacy (aerobic and functional fitness) and safety of high-intensity resistance and sprint-cycle interval training in at-risk older adults. METHODS: Forty-eight participants (30 women; 69±6 years; 28.0±5.5 kg/m2; 60% with ≥2 chronic diseases) trained 3 days/week for 6 weeks. Participants were randomized to conditions: 1) high-intensity sprint interval cycle training (SIT; N=17); 2) high-intensity resistance training (HIRT; N=20); or 3) moderate-intensity continuous aerobic exercise (MICE; active control; N=11). Baseline and post-training measures included: maximal aerobic capacity (VO2max), body composition, functional movement screen (FMS), floor-transfer-time (FTT), timed-up-and-go (TUG), balance, and flexibility. Subjective measures were: satisfaction with physical function, mobility, and physical activity enjoyment (PACES). Data analysis: repeated measure ANOVA and paired-t tests (P<0.05). RESULTS: VO2max improved similarly in all groups (SIT 2.2±0.3; HIRT=3.5±0.7. MICE 2.1±0.5 ml/kg/min, P<0.01 for all). Both high-intensity groups improved in FTT (HIRT=17%, P=<0.01; SIT =12%, P<0.05) and FMS (HIRT=17%, SIT =10%, P<0.01). Only HIRT improved in TUG (10.6%) and balance (9%). Perceived satisfaction with physical function improved in all groups (HIRT=389%; SIT=266%; MICE = 167%; all P<0.01) with similarly high overall enjoyment (5.8-6.3 out of 7; P<0.05). No injuries or adverse events occurred with training. CONCLUSION: HIRT and SIT required less time (~28 minutes) than MICE guidelines, elicited equivalent gains in aerobic fitness, and appear to be safe for older adults with chronic disease. Additional functional fitness benefits (mobility and FMS) accompanied high-intensity training (SIT/HIRT). HIRT elicited improvements in mobility, balance, and 4 of 7 FMS measures compared to SIT (2 of 7 FMS measures). These HIRT specific gains are associated with enhanced independence and ability to perform activities of daily living. Future studies should confirm these findings and assess longer training durations.