Hourly 4-minute walking breaks from sitting following aerobic exercise reduce postprandial non-HDL cholesterol in healthy young adults: A randomized crossover trial

BACKGROUND: It is unclear how activity breaks from prolonged sitting after aerobic exercise affects postprandial glucose, triglycerides, and cholesterol. OBJECTIVE: To investigate the acute effects of volume- and intensity-matched activity breaks after aerobic exercise on postprandial glucose, triglyceride, and cholesterol in healthy young adults. METHODS: Randomized, single-blind, 4-period crossover trial conducted among 12 sedentary, healthy young adults (age 22 ± 3 years). They took part in 4 conditions of 7 hours each in random order with a washout period of at least 4 days: (1) uninterrupted sitting for 6.5 hours after aerobic exercise (Ex-Sit); (2) 2-minute walking breaks from sitting every 30 minutes after aerobic exercise (Ex-Break2); (3) 4-minute walking breaks from sitting every 60 minutes after aerobic exercise (Ex-Break4); (4) 8-minute walking breaks from sitting every 120 minutes after aerobic exercise (Ex-Break8). Aerobic exercise consisted of 30 minutes of moderate-intensity walking on a treadmill. The total amount of light-intensity walking breaks was 24 minutes. Postprandial serum triglycerides, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol (HDL-C), total cholesterol, and capillary glucose were measured over 7 hours. Linear mixed models were used to explore between-condition differences. RESULTS: Non-HDL-C incremental area under the curve was significantly reduced by 36.07 (95% CI: −69.76, −2.39) mg/dL.7 hours (P = .030) and 33.02 (95% CI: −65.42, −0.61) mg/dL.7 hours (P = .044) in Ex-Break4 compared to Ex-Sit and Ex-Break8, respectively. No significant differences were observed for the remaining variables. CONCLUSION: Taking hourly 4-minute walking breaks from sitting after aerobic exercise can reduce postprandial non-HDL-C levels in sedentary, healthy young adults. Clinical trial registration: The study was registered with ClinicalTrials.gov with the ID number NCT06106464.