Summary by Utah Sports and Wellness

Link to Original Article:

  • Cell Metabolism
  • Volume 33 – May 2021
  • Department of Clinical Sciences at Karolinska Institute
  • Increased exercise amount over time


Exercise training positively affects metabolic health through increased glucose regulation:

  • Mitochondria are the primary source of cellular ATP synthesis.
  • The size and function of the mitochondrial pool are vital for metabolic health and muscular function.
  • Mitochondrial capacity is a strong proxy for metabolic function and health.
  • In many pathological states, mitochondria display a reduced ability to respond to nutrient supply.

Acute exercise increases the total Nrf2 protein within minutes:

  • Nfr2 is the master regulator of several hundred genes involved in the antioxidant defense.
  • Exercise training has proven to be a powerful tool to act as a preventative treatment against many metabolic disorders by stimulating glucose uptake.
  • Extreme amounts of exercise have been associated with negative effects on cardiac health.
  • In competitive sports, it is established exercise improves performance, whereas too much training leads to staleness and reduced performance.
  • There is a bell-shaped relationship between exercise training load and mitochondrial function.

These authors also note:

  • After the recovery phase, when training load is drastically reduced, performance peaks.
  • Mitochondrial function is an important determinant of insulin sensitivity.
  • Mitochondrial impairment is associated with impaired glucose tolerance.
  • Also assessed were the continuous blood glucose profiles in world-class endurance athletes. They had impaired glucose control compared with a matched control group.