Important parameters of intermittent fasting on athletic performance include weight loss, maintenance of muscle mass, and post exercise metabolism due to decreases in glycogen stores, low levels of insulin, increase in hormones responsible for lipolysis (fat breakdown), and an increase in free fatty acids (Paoli 2019, Gieske 2018).
While intermittent fasting and time restricted eating have gained popularity, it is important for athletes to appreciate how implementing this change in eating impacts metabolic adaptations, body composition, physical performance and overall endurance, and recovery.
Additionally, based on the findings one can conclude that while there isn’t a conclusive difference in overall performance in the fasting versus fed state, the fasting state stimulated a higher level of fat oxidation that occurred for 30 minutes post exercise (Rocha da Silva 2018).
This is a positive finding, in that we know there isn’t a negative effect as long as exercise performance was maintained at
All in all, intermittent fasting in athletes demonstrates a beneficial impact on metabolic parameters and an increase in lipid oxidation, however, does not demonstrate an improvement in athletic performance and recovery.