Nutrition · Moderate evidence

Carbohydrates and Workout Performance

Carbohydrates sustain long, high-volume sessions; for short resistance training sessions, intake from the previous day is usually sufficient, and daily totals should match the training load.

Systematic review and joint society position stand · 2 sources · 2 min

What the studies show

  • For resistance training sessions lasting up to about one hour, extra carbohydrates did not consistently improve performance.
  • Long, high-volume sessions benefit from higher carbohydrate intake before and during training.
  • The joint position stand recommends adjusting carbohydrates to the training load, ranging from 3 to 10 g/kg/day depending on volume.

How Letz applies it

Carbohydrates serve as the adjustment macronutrient: they increase on training days and decrease on rest days while maintaining the weekly average.

Numbers derived from this rule

ParameterRangeWeightRule
Dietary fat20–35 % of calories50%Fat between 20 and 35% of calories; below 20% impairs hormones and adherence.Calorie surplus for muscle gain · Carbohydrates and Workout Performance

Who it applies to

Active adults and athletes.

Limits

Requirements vary widely based on volume, duration, and goals; very-low-carbohydrate diets impair long sessions.

Sources

More in Nutrition

  • Protein and Training AdaptationSufficient protein can support gains in lean mass and strength alongside training; the response varies and does not increase indefinitely with higher intakes.
  • Higher Protein Intake During a Calorie DeficitIn a deficit, higher protein protects lean mass and can even allow muscle gain alongside intense training; the effective range rises to approximately 1.6 to 2.4 g/kg.
  • Rate of weight lossLosing weight slowly, at around 0.5 to 1% of body weight per week, better preserves lean mass, strength, and metabolic rate compared to rapid weight loss.
  • Distribute protein throughout the dayDividing protein into servings of around 0.4 g/kg across four or more meals stimulates protein synthesis more than concentrating everything into one or two.