Which hormone can protect glycogen reserves during exercise by increasing lipid use?

The hormone that effectively protects glycogen reserves during exercise while simultaneously increasing lipid utilization is growth hormone. Growth hormone stimulates lipolysis, which is the breakdown of fat stores into free fatty acids that can be used for energy. During prolonged physical activity, this process helps to conserve glycogen by shifting the body’s energy expenditure from glucose (derived from glycogen) to fatty acids, thereby extending endurance and performance.

In addition to fat metabolism, growth hormone also plays a role in promoting muscle growth and recovery, which can indirectly conserve glycogen by improving overall energy efficiency during exercise. This dual action of enhancing lipid oxidation while sparing glycogen makes growth hormone a significant factor in energy metabolism during physical activity.

Other hormones like cortisol may have a role in energy metabolism as well but are more associated with stress response and can actually lead to increased protein breakdown and, under prolonged stress, might not be beneficial for glycogen conservation. Testosterone primarily focuses on muscle mass and strength but does not play a central role in promoting lipid use during exercise to protect glycogen. Lastly, insulin is more involved in the uptake of glucose and storage of glycogen rather than increasing lipid utilization during exercise.