Interval training in men at risk for insulin resistance

Area of Science:

• Exercise Physiology
• Metabolic Health
• Cardiovascular Fitness

Background:

• Insulin resistance is a growing concern, particularly in men.
• Exercise training is a cornerstone for managing metabolic health.
• Comparing different exercise modalities is crucial for optimizing interventions.

Purpose of the Study:

• To compare the effects of steady-state aerobic training (AER) versus interval training (INT) on insulin resistance and related metabolic markers.
• To assess secondary outcomes including cardiorespiratory fitness (VO2max), anthropometry, and metabolic syndrome severity.
• To investigate differential responses based on baseline insulin resistance levels.

Main Methods:

• A 3-month eucaloric training intervention comparing AER and INT in men at risk for insulin resistance.
• Primary outcome measures included oral glucose tolerance testing (OGTT) and HOMA-IR at 24 and 72 hours post-exercise.
• Secondary measures included VO2max, body mass, body fat percentage, and metabolic syndrome z-score (zMS).

Main Results:

• Both AER and INT significantly improved 24-hour OGTT. INT also significantly improved HOMA-IR at 24 and 72 hours, while AER did not.
• VO2max improved similarly in both groups. INT led to significant reductions in body mass and body fat percentage, unlike AER.
• While both training types improved zMS overall, stratified analysis showed INT improved HOMA-IR in both low and high baseline groups, whereas AER only improved it in the high HOMA-IR group.

Conclusions:

• Eucaloric AER and INT demonstrate comparable effects on fasting glucose, OGTT, and VO2max.
• INT may offer superior benefits for improving insulin resistance (HOMA-IR) and reducing metabolic syndrome severity compared to AER.
• Exercise prescription should consider individual metabolic profiles for optimal outcomes.