Cyclical Ketogenic Diet (CKD) — Diets

Periodic ketogenic cycling with scheduled carbohydrate refeeds for athletic performance and metabolic flexibility.

Overview

The Cyclical Ketogenic Diet (CKD) alternates between standard ketogenic periods (5-6 days) and higher carbohydrate refeeds (1-2 days). This approach aims to maintain the metabolic benefits of ketosis while periodically replenishing muscle glycogen for high-intensity exercise performance. The carb-up phase targets 400-600 g of carbohydrates to fully reload glycogen stores. While less studied than SKD, CKD is widely used in bodybuilding and strength sports. Limited evidence suggests it may improve adherence and athletic performance compared to continuous keto while preserving insulin sensitivity benefits.

Indications

  • Athletic performance on ketogenic diets
  • Muscle glycogen repletion for high-intensity training
  • Improved dietary adherence through cycling
  • Metabolic flexibility training

Mechanism of Action

5-6 days of carb restriction maintains ketone-adapted metabolism and fat oxidation

Dosing

CompoundDoseFrequencyNotes
Cyclical Ketogenic DietSKD 5-6 days + carb refeed 1-2 daysWeekly cycleRefeed: 400-600 g carbs, reduced fat; focus on complex carbs

Evidence Grade

GRADE C

Safety & Contraindications

  • Rapid shifts between metabolic states may cause GI discomfort
  • Risk of excessive carb intake during refeeds leading to fat regain
  • Not suitable for epilepsy management where consistent ketosis is required
  • Requires disciplined tracking of macronutrients