A single exercise session increases insulin sensitivity in normal weight and overweight/obese adolescents

Area of Science:

• Exercise Physiology
• Metabolic Health
• Adolescent Health

Background:

• Overweight/obesity is associated with impaired glucose control and insulin sensitivity in adolescents.
• The impact of acute aerobic exercise on metabolic responses in overweight/obese adolescents is not well understood.

Purpose of the Study:

• To investigate the effect of a single aerobic exercise session on postprandial glucose control in adolescents.
• To determine if overweight/obesity alters the acute or residual effects of exercise on metabolic health.

Main Methods:

• A randomized controlled trial comparing three conditions: no exercise, exercise 40 minutes before a meal, and exercise 17 hours before a meal.
• Participants included normal weight (NW) and overweight/obese (OW/Ob) adolescents with habitually low physical activity.
• Measurements included glucose, insulin, insulin sensitivity, plasma fatty acids, and carbohydrate oxidation after a test meal.

Main Results:

• OW/Ob adolescents exhibited higher fasting glucose and insulin, and lower insulin sensitivity compared to NW adolescents.
• Both same-day and prior-day exercise significantly reduced glucose and insulin response to a meal and increased insulin sensitivity.
• The magnitude of exercise-induced metabolic improvements did not differ between NW and OW/Ob groups.

Conclusions:

• Moderate-intensity aerobic exercise enhances insulin sensitivity in both normal weight and overweight/obese adolescents.
• The beneficial metabolic effects of exercise can last for at least 17 hours.
• Overweight/obesity does not impair the acute positive impact of exercise on adolescent metabolic health.