Low-carbohydrate and ketogenic diets maintain peak power during one-time maximal efforts but reduce the ability to perform multiple high-intensity bursts in succession, meaning the effectiveness of...
Mechanism
Synthesis from 1 study
Low-carb diets deplete muscle sugar, which hurts repeated sprints because the muscle can't make energy fast enough and can't contract as strongly. But for one quick burst, the muscle uses a different energy system that doesn't need sugar, so power stays high. Faster recovery between efforts helps...
Most probable mechanism
When carbs are low, muscles run out of sugar needed for quick energy bursts during repeated sprints, so they can't produce power fast enough for multiple efforts. But for one quick jump or sprint, the muscle uses a different energy system that doesn't need sugar, so power stays strong. The lack of sugar also messes with how muscles contract by reducing calcium release, making repeated efforts even harder.
Dietary carbohydrate restriction reduces plasma glucose and insulin, suppressing glycogen synthesis and promoting glycogen breakdown until intramuscular stores are depleted.
Depleted glycogen limits substrate availability for glycolytic enzymes, reducing glycolytic flux and ATP production during high-intensity efforts.
During single, short-duration maximal efforts (<10 seconds), ATP is supplied primarily by phosphocreatine breakdown, which does not require glycogen or glycolysis.
Glycogen depletion in inter- and intra-myofibrillar compartments of fast-twitch muscle fibers reduces calcium release from the sarcoplasmic reticulum during excitation-contraction coupling.
Reduced calcium availability decreases cross-bridge cycling rate and force generation in fast-twitch fibers during repeated contractions.
Diminished glycolytic ATP and impaired calcium handling together reduce mean power output and sprint speed during repeated high-intensity efforts.
Enhanced fat oxidation increases oxidative ATP production during recovery, supporting phosphocreatine resynthesis and maintaining peak power across repeated bouts.
Evidence from Studies
Supporting (1)
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Effects of Low-Carbohydrate and Ketogenic Diets on Anaerobic Performance in Competitive Athletes: A Systematic Review and Meta-Analysis
Contradicting (0)
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