Resistance Training And High-intensity Interval Training Improve Cardiometabolic Health In Older Adults: A Meta-analysis

Abstract

PURPOSE: Older adults have an increased risk of developing cardiometabolic disease including cardiovascular disease and type 2 diabetes. Progressive resistance training (PRT) and high-intensity interval training (HIIT) individually improve cardiometabolic health (CMH) in older adults. However, whether a combination of the two prescriptions provides greater benefit is yet to be explored. We conducted a systematic review and meta-analysis of controlled trials investigating the effect of PRT, HIIT and combination PRT+HIIT (COMB) on CMH in older adults with moderate cardiometabolic risk. METHODS: Nine databases were searched from inception until September 2019. We included studies comparing PRT, HIIT or COMB vs usual care that reported ≥2 modifiable CMH risk factors. Standardized mean (SMD) and mean differences (MD) were calculated using a random-effects inverse variance model. Heterogeneity and risk of bias were assessed according to Cochrane guidelines. RESULTS: We analysed 451 participants from ten studies (7 PRT, n=149, 2 HIIT, n=25, 1 COMB, n=60), 40.6% male with a mean age of 67.7±1.8 years. Training ranged from 2-4 times per week for 22±16 weeks. Compared to usual care, exercise significantly improved body mass index (BMI) (MD -0.36 [-0.50,-0.22], p≤0.0001), body fat % (BF%) (SMD -0.60 [-1.13, -0.06], p=0.03), peak aerobic capacity (SMD 0.40 [0.13, 0.68], p=0.004), triglycerides (SMD -0.22 [-0.45, 0.00] p=0.05) and fasting blood glucose (FBG) (SMD -0.30 [-0.54, -0.05], p=0.02). PRT alone significantly improved BMI (MD -0.37 [-0.53, -0.21], p=0.00001), BF% (SMD -0.91 [-1.70, -0.13], p=0.02) and lean body mass (SMD 0.96 [0.05, 1.87], p=0.04). COMB improved triglycerides (SMD -0.44 [-0.79, -0.08], p=0.02) and FBG (SMD -0.41 [-0.76, -0.05], p=0.02). CONCLUSIONS: Exercise improves CMH in older adults, with PRT interventions eliciting significant improvements in body composition. COMB exercise was the only modality to improve triglycerides and blood glucose. Further research is warranted on COMB, HIIT and PRT training, focusing on volume and intensity to investigate differences in effect. More thorough CMH outcome and exercise prescriptive element reporting is warranted in order to identify optimal exercise prescription for improving CMH in older adults.