Exercise beneficial in metabolic syndrome only when weight loss targets are met

Exercise interventions improve cardiometabolic health in people with metabolic syndrome (MetS), but achieving these benefits may depend on weight loss, as shown in a study.

A total of 228 adults (mean age 55.3 years, 42.1 percent female, mean BMI 32.5 kg/m²) with MetS and less than 120 min/wk of moderate-intensity physical activity participated in the study. 

The participants were randomly allocated to either the standard-care, nonexercise group (control group, n=58) or the standard-care plus physical activity group (exercise group, n=170). Those in the exercise group underwent a 16-week supervised high-intensity interval training programme, with three 43-min sessions performed each week.

Outcomes included MetS (MetS z-score), insulin resistance (HOMA-IR), cardiorespiratory fitness (VO_2PEAK), maximal cycling power (W_PEAK), and body weight/composition. These parameters were assessed at baseline and after the intervention.

In the exercise group, 78 participants achieved the weight loss predicted from estimated exercise energy expenditure (−3.3 kg), 38 did not meet the expected weight loss (−0.7 kg), and 54 gained weight (1.1 kg) after 16 weeks.

Compared with the control group, the exercise group showed significant improvement in cardiorespiratory fitness regardless of body weight loss response (p<0.001 for all).

However, only participants who achieved the expected weight loss in the exercise group had significant improvements in MetS z-score (−0.31) and HOMA-IR (−0.7) compared with the control group (p<0.001 for both).