Consecutive days of exercise decrease insulin response more than a single exercise session in healthy, inactive men.

Area of Science:

• Exercise Physiology
• Metabolic Health
• Endocrinology

Background:

• A single exercise bout can reduce insulin response 12-24 hours post-exercise.
• The impact of varied exercise patterns on insulin sensitivity remains unclear.

Purpose of the Study:

• To investigate the effect of different exercise patterns on post-exercise insulin and glucose metabolism.
• To compare insulin and glucose responses following consecutive, alternate, and single exercise bouts.

Main Methods:

• Ten healthy males completed three exercise trials (3 consecutive days, 3 alternate days, 1 single bout) and a control.
• Exercise involved 60 minutes of walking at ~70% VO2max.
• An oral glucose tolerance test (OGTT) was administered 12-14 hours post-exercise, with blood sampling for glucose, insulin, and C-peptide.

Main Results:

• No significant differences in glucose or C-peptide incremental area under the curve (iAUC) were observed across trials.
• Insulin iAUC was significantly reduced by 34.9% in the 3 consecutive days trial compared to the control (p < 0.01).

Conclusions:

• Three consecutive days of moderate-intensity exercise improve insulin response to an OGTT in healthy males.
• Single or alternate day exercise bouts may not provide a sufficient stimulus to lower insulin response.
• Exercise frequency is a critical factor in modulating insulin sensitivity.