Combined training prescriptions for improving cardiorespiratory fitness, physical fitness, body composition, and cardiometabolic risk factors in older adults: Systematic review and meta-analysis of controlled trials

BACKGROUND: Improved physical fitness is important for preventing COVID-19-related mortality. So, combined training can effectively increase peak oxygen consumption, physical fitness, body composition, blood pressure, and the healthrelated characteristics of adults; however, its impact in the elderly remains unclear. METHODS: This systematic review and meta-analysis aimed to evaluate the effects of combined training on older adults. Four electronic databases (PubMed, Scopus, Medline, and Web of Science) were searched (until April 2021) for randomized trials comparing the effect of combined training on cardiorespiratory fitness, physical fitness, body composition, blood pressure, and cardiometabolic risk factors in older adults. RESULTS: Combined training significantly improved peak oxygen consumption compared to no exercise (WMD = 3.10, 95% CI: 2.83 to 3.37). Combined resistance and aerobic training induced favorable changes in physical fitness (timed up-and-go = −1.06, 30-s chair stand = 3.85, sit and reach = 4.43, 6-minute walking test = 39.22, arm curl = 4.60, grip strength = 3.65, 10-m walk = −0.47, maximum walking speed = 0.15, one-leg balance = 2.71), body composition (fat mass = −2.91, body fat% = −2.31, body mass index = −0.87, waist circumference = −2.91), blood pressure (systolic blood pressure = −8.11, diastolic blood pressure = −4.55), and cardiometabolic risk factors (glucose = −0.53, HOMA-IR = −0.14, high-density lipoprotein = 2.32, total cholesterol = −5.32) in older individuals. Finally, the optimal exercise prescription was ≥ 30 min/session × 50–80% VO2peak, ≥ 3 times/week for ≥ 12 weeks and resistance intensity 70–75% one-repetition maximum, 8–12 repetitions × 3 sets. CONCLUSIONS: Combined training improved VO2peak and some cardiometabolic risk factors in older populations. The dose–effect relationship varied between different parameters. Exercise prescriptions must be formulated considering individual needs during exercise.