Continuous and interval are the two types of aerobic exercise training commonly used for health promotion. We sought to determine which aerobic exercise training program results in larger health improvements in metabolic syndrome (MetS) individuals.
One hundred twenty-one MetS patients (age, 57 ± 8 yr; weight, 92 ± 15 kg; and MetS factors, 3.8 ± 0.8 components) with low initial cardiorespiratory fitness (CRF) (V˙O2peak, 24.0 ± 5.5 mL·kg−1·min−1) were randomized to undergo one of the following 16-wk exercise program: (a) 4 × 4-min high-intensity interval training at 90% of HRMAX (4HIIT group; n = 32), (b) 50-min moderate-intensity continuous training at 70% of HRMAX (MICT group; n = 35), (c) 10 × 1-min HIIT at 100% of HRMAX (1HIIT group; n = 32), or (d) no exercise control group (CONT; n = 22). We measured the evolution of all five MetS components (i.e., MetS Z Score) and CRF (assessed by V˙O2peak) before and after intervention.
MetS Z score decreased 41% after 4HIIT (95% confidence interval [CI], 0.25–0.06; P < 0.01) and 52% in MICT (95% CI, 0.24–0.06; P < 0.01), whereas it did not change in 1HIIT (decreased 24%; 95% CI, −0.16 to 0.03; P = 0.21) and CONT (increased 20%; 95% CI, −0.19 to 0.04; P = 0.22). However, the three exercise groups improved similarly their V˙O2peak (4HIIT, 11%; 95% CI, 0.14–0.33; MICT, 12%; 95% CI, 0.18–0.36; and 1HIIT, 14%; 95% CI, 0.21–0.40 L·min−1; all P < 0.001).
Our findings suggest that in sedentary individuals with MetS and low initial CRF level any aerobic training program of 16 wk with a frequency of three times per week is sufficient stimulus to raise CRF. However, the more intense but shorter 1HIIT training program is not effective on improving MetS Z score, and thus we caution its recommendation for health promotion purposes in this population.
Exercise Physiology Laboratory at Toledo, University of Castilla-La Mancha, Toledo, SPAIN
Address for correspondence: Ricardo Mora-Rodriguez, Ph.D., Exercise Physiology Laboratory at Toledo, University of Castilla-La Mancha, 45071 Toledo, Spain; E-mail: email@example.com.
Submitted for publication October 2018.
Accepted for publication March 2019.
Online date: March 19, 2019