- Aug 14, 2018
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Protein gets the headlines, but carbohydrates are the fuel question that quietly decides how a hard session feels. Muscle glycogen — the stored form of carbohydrate in muscle — is the main energy source for high-intensity lifting, and the research on how much it matters is more nuanced than either the high-carb or low-carb camps usually admit.
A single hard resistance session doesn't empty the tank the way a marathon does. Studies measuring glycogen after typical bodybuilding-style workouts generally find depletion in the range of 25–40% in the muscles trained, and normal mixed eating restores it within about 24 hours. That's why the endurance world's aggressive carbohydrate targets don't transfer directly to the weight room. Sports-nutrition position stands aimed at lifters generally land around 3–7 g/kg of body weight per day depending on training load — far above a ketogenic intake, far below what a distance athlete eats.
Where the evidence does show an effect is at the extremes. Trials that put lifters on very low-carbohydrate diets sometimes find small reductions in high-volume performance — total reps across many sets — especially in the first weeks before adaptation, while maximal strength on low-rep work tends to hold up better. Henselmans and colleagues' work on glycogen and performance made the useful point that glycogen depletion has to be quite substantial before it meaningfully blunts a single session's output; you're more likely to notice it across a week of high-volume training on a deficit than in one workout after a light-carb day.
The cutting context is where carbs earn their keep for most people here: on reduced calories, keeping carbohydrate around training and keeping total intake steadier tends to protect training quality, and training quality is what protects muscle. The popular "train low" idea — deliberately doing some sessions with low glycogen to drive endurance adaptations — comes from endurance research and has weak support as a hypertrophy strategy; most lifters are better served fuelled.
Practical read: you don't need endurance-athlete carb loading to lift well, but chronically very low carbohydrate plus high training volume is a combination the research doesn't flatter. Match intake to the work, bias it toward the training window if your day is uneven, and judge by performance in the log book rather than ideology.
Where do you land — do you track carbs at all, or just protein and total calories? Has anyone here tested genuinely low-carb training for a full block, and what did your top sets do?
A single hard resistance session doesn't empty the tank the way a marathon does. Studies measuring glycogen after typical bodybuilding-style workouts generally find depletion in the range of 25–40% in the muscles trained, and normal mixed eating restores it within about 24 hours. That's why the endurance world's aggressive carbohydrate targets don't transfer directly to the weight room. Sports-nutrition position stands aimed at lifters generally land around 3–7 g/kg of body weight per day depending on training load — far above a ketogenic intake, far below what a distance athlete eats.
Where the evidence does show an effect is at the extremes. Trials that put lifters on very low-carbohydrate diets sometimes find small reductions in high-volume performance — total reps across many sets — especially in the first weeks before adaptation, while maximal strength on low-rep work tends to hold up better. Henselmans and colleagues' work on glycogen and performance made the useful point that glycogen depletion has to be quite substantial before it meaningfully blunts a single session's output; you're more likely to notice it across a week of high-volume training on a deficit than in one workout after a light-carb day.
The cutting context is where carbs earn their keep for most people here: on reduced calories, keeping carbohydrate around training and keeping total intake steadier tends to protect training quality, and training quality is what protects muscle. The popular "train low" idea — deliberately doing some sessions with low glycogen to drive endurance adaptations — comes from endurance research and has weak support as a hypertrophy strategy; most lifters are better served fuelled.
Practical read: you don't need endurance-athlete carb loading to lift well, but chronically very low carbohydrate plus high training volume is a combination the research doesn't flatter. Match intake to the work, bias it toward the training window if your day is uneven, and judge by performance in the log book rather than ideology.
Where do you land — do you track carbs at all, or just protein and total calories? Has anyone here tested genuinely low-carb training for a full block, and what did your top sets do?