Why are physical activity breaks more effective than a single session of isoenergetic exercise in reducing postprandial glucose? A systemic review and meta-analysis

ABSTRACT

Previous studies revealed that interrupting sitting time with short, frequent physical activity (PA) breaks were more effective than a single session of isoenergetic exercise in reducing postprandial glucose. However, in those studies, the expected glucose-lowering effects of single-session exercises were diminished or even eliminated by exercise-induced glucose counterregulation as evidenced by the higher glucose levels during or after exercise compared to uninterrupted sitting. This study was aimed to investigate whether glucose counterregulation is a potential explanation of PA breaks being more effective than a single session of isoenergetic exercise in reducing postprandial glucose. We meta-analysed the standardized mean differences (SMD) of glucose incremental area under the curve (iAUC). PA breaks were more effective than single-session exercise in reducing glucose iAUC (5 studies, SMD = −0.581; 95% confidence interval [CI], −0.777 to −0.385; P < 0.0001) when exercise-induced glucose counterregulation occurred. There was no significant difference in glucose iAUC between PA breaks and single-session exercises (2 studies, SMD = 0.302; 95% CI, −0.107 to 0.711; P = 0.451) when glucose counterregulation did not occur. We concluded that the exercise-induced glucose counterregulation was a potential explanation of PA breaks being more effective than a single session of isoenergetic exercise in reducing postprandial glucose responses. (PROSPERO ID: CRD42020175737).

KEYWORDS:

• Physical activity
• sitting
• health

Authors’ contributions

Conceptualization: [Tongyu Ma]; Methodology: [Tongyu Ma], [Hannah Gouldrup]; Formal analysis and investigation: [Tongyu Ma], [Hannah Gouldrup]; Writing – original draft preparation: [Tongyu Ma], [Hannah Gouldrup]; Writing – review and editing: [Tongyu Ma], [Hannah Gouldrup].

Availability of data and material

The datasets generated during and/or analyzed using the current study are available from the corresponding author on reasonable request.

Disclosure statement

Hannah Gouldrup and Tongyu Ma declare that they have no conflict of interest.

Supplementary material

Supplemental data for this article can be accessed online https://doi.org/10.1080/02640414.2020.1812196.