Most athletes need between 1.4 and 2.0 grams of protein per kilogram of body weight per day. For a 180-pound (82 kg) person, that works out to roughly 115 to 164 grams of protein daily. This range, established by the International Society of Sports Nutrition, covers the needs of most people who exercise regularly, but where you fall within it depends on your sport, your goals, and whether you’re cutting weight.
Endurance vs. Strength Athletes
The 1.4 to 2.0 g/kg range isn’t one-size-fits-all. Endurance athletes, such as runners, cyclists, and swimmers, generally need less protein than strength athletes. Their recommended range sits between 1.0 and 1.6 g/kg per day, with elite endurance athletes who train at high volumes pushing toward the upper end. The primary role of protein for these athletes is repairing muscle damage from prolonged activity and supporting immune function during heavy training blocks.
Strength and power athletes aiming to build muscle need to be at the higher end. Research on weightlifters consistently points to 1.4 to 2.0 g/kg per day as sufficient for maximizing muscle growth, with some reviews suggesting a narrower sweet spot of 1.5 to 2.0 g/kg. Beyond supporting muscle repair, this level of intake helps maintain a positive protein balance, meaning your body is building more muscle protein than it breaks down.
When You Need More Than 2.0 g/kg
Two situations push protein needs above the standard range. The first is dieting. When you’re in a calorie deficit, whether for a weight cut, body recomposition, or making a weight class, your body is more likely to break down muscle for energy. To protect lean mass during energy restriction, recommendations jump to 1.6 to 2.4 g/kg per day. The more aggressive the calorie deficit, the closer you should aim to the top of that range.
The second situation is resistance-trained individuals who are already lean and want to push further. Some evidence suggests that intakes as high as 2.3 to 3.1 g/kg per day can help maximize lean mass retention during aggressive cuts. There’s also preliminary data showing that intakes above 3.0 g/kg may promote fat loss in people who lift regularly, though this is a newer area of study and the practical benefit over simply eating 2.0 g/kg is modest for most people.
How to Spread Protein Across the Day
Total daily protein matters more than obsessing over exact timing, but distribution still plays a role. A good target is roughly 0.25 g/kg of body weight per meal, which translates to about 20 to 40 grams of protein per sitting for most athletes. Spreading intake across meals every three to four hours gives your muscles repeated opportunities to activate the repair and growth process.
Each of those meals should contain enough of the amino acid leucine to trigger muscle protein synthesis. The threshold is roughly 2 to 3 grams of leucine per meal. Most animal-based protein sources hit this naturally in a 25 to 40 gram serving. Plant-based sources can get there too, but you may need slightly larger portions or strategic combinations to reach that leucine level.
There’s also value in eating protein before bed. A serving of 30 to 40 grams of a slow-digesting protein like casein before sleep has been shown to increase overnight muscle protein synthesis and slightly boost metabolic rate.
As for the post-workout “anabolic window,” the urgency has been overstated. A meta-analysis of protein timing studies found that consuming protein within one hour of training did not significantly improve strength or muscle gains compared to eating it a few hours later. The real window appears to be four to six hours around a training session, depending on when your last meal was. If you ate a protein-rich meal two hours before lifting, you don’t need to rush to a protein shake the moment you rack the bar.
Plant-Based Athletes
Athletes eating entirely plant-based diets can meet their protein needs without any clear disadvantage for training adaptations, provided they eat enough total protein. The main consideration is digestibility. Plant proteins contain compounds that slow digestion and reduce the proportion of amino acids that actually reach your bloodstream compared to animal sources. This is a property of the food matrix (fiber, cell walls) rather than the protein itself.
The practical takeaway is that vegan athletes may benefit from aiming toward the higher end of the recommended range to compensate for this reduced absorption. How much higher isn’t precisely established, but the adjustment is modest. Prioritizing higher-quality plant sources like soy, pea protein, and lentils, and combining complementary sources across the day, helps close the gap. Modeling studies on plant-based diets for rugby players found that well-planned meals could deliver about 2.9 grams of leucine per meal across four daily meals, which exceeds the threshold needed to stimulate muscle growth.
Older Athletes Don’t Need a Different Target
Sedentary older adults typically develop “anabolic resistance,” a reduced ability to use dietary protein for muscle building, which contributes to age-related muscle loss. This has led some people to assume that older athletes also need substantially more protein. But master athletes (generally those over 35 to 40 competing in organized sport) appear to be a different story. Research shows they maintain body composition, muscle mass, and aerobic fitness comparable to untrained adults decades younger. Their muscle characteristics and protein metabolism closely resemble those of young athletes, which means the standard 1.4 to 2.0 g/kg recommendation likely applies to them as well.
Safety at Higher Intakes
A persistent concern is that high protein diets damage the kidneys. This idea traces back to early animal studies where kidney damage was observed in rats that had already had one kidney removed. In healthy athletes with normal kidney function, the evidence tells a different story. A one-year crossover study in resistance-trained men consuming 2.5 to 3.3 g/kg per day found no harmful effects on blood lipids, liver function, or kidney function. Shorter studies at intakes above 3.0 g/kg per day have reached the same conclusion.
For healthy athletes without pre-existing kidney conditions, protein intakes of 1.4 to 2.0 g/kg per day are well-established as safe, and even substantially higher intakes have not shown harm in the available research. The standard recommendation of 0.8 g/kg per day (the RDA) is designed for sedentary individuals and is insufficient for anyone training seriously.