Hormonal

Acute high-intensity exercise increases circulating irisin levels, and this elevated irisin directly modulates human muscle metabolism by activating AMPK, thereby facilitating glucose and lipid uptake.

To trigger the release of irisin, which helps your muscles process glucose and fats more efficiently, you need to perform high-intensity exercise. Moderate, steady-state exercise may not significantly raise irisin levels. Focus on intensity (like sprint intervals) to get this metabolic benefit, but understand that the hormone spike is temporary and serves as a signal for immediate metabolic adaptation rather than a permanent state change.