Does taking breaks from sitting improve glycemic control? Original paper

Excessive sedentary time is associated with obesity, metabolic syndrome, and type 2 diabetes. Can taking more breaks from sitting improve the glycemic control and metabolic profile of sedentary adults with obesity?

In this 4-week randomized controlled trial, 16 people aged 44–53 (BMI: ≥30) wore continuous glucose and activity monitors. After a baseline period (1 week), they were divided into two groups (3 weeks): a Frequent Activity Breaks from Sitting (FABS) group and a nonintervention control group. Every 30 minutes, a smartwatch app told the FABS group to exercise for 3 minutes at low-to-moderate intensity — by walking, stair-climbing, or doing body-weight squats, for instance.

Before and after the trial, five methods were used to assess glycemic control (the primary outcome): continuous glucose monitoring, oral glucose tolerance test (OGTT), homeostatic model of insulin resistance (HOMA-IR), hepatic insulin resistance index (HIRI), and Matsuda index. Two secondary outcomes were also assessed: clinical chemistry (via blood samples) and skeletal muscle lipidome (via vastus lateralis biopsies).

FABS decreased glucose variation and fasting blood glucose levels, with greater daily activity yielding greater benefits. In contrast, glucose tolerance and average 24-hour glucose curves didn’t change.

FABS increased two long-chain triglycerides and nonsignificantly decreased LDL-C. Other blood markers and the skeletal muscle lipidome didn’t change.

All outcomes remained the same in the control group.

The authors assessed only within group changes; they didn’t compare results between groups (the preferred method in randomized controlled trials).

Compared to baseline, the FABS group walked only 744 steps more (10.4 minutes) per day, with no changes in total sitting time or the number of transitions from sitting to standing.