Most people benefit from 20 to 40 grams of protein after a workout, with the ideal amount depending on your body size. A more precise target is 0.4 to 0.5 grams per kilogram of your body weight. For a 170-pound (77 kg) person, that works out to roughly 31 to 39 grams.
The Per-Meal Target by Body Weight
Flat recommendations like “eat 30 grams of protein” are a decent starting point, but your body size matters. Current research points to 0.4 g/kg per meal as a solid baseline and 0.55 g/kg per meal as a practical upper limit when you’re spreading protein across at least four meals a day. Here’s what that looks like at different body weights:
- 130 lbs (59 kg): 24–32 g per meal
- 155 lbs (70 kg): 28–39 g per meal
- 180 lbs (82 kg): 33–45 g per meal
- 210 lbs (95 kg): 38–52 g per meal
These numbers apply to every protein-rich meal, not just the post-workout one. Your post-workout serving doesn’t need to be dramatically larger than any other meal. What matters most is that you’re hitting these targets consistently throughout the day.
Why Leucine Matters More Than Total Grams
Protein triggers muscle repair, but a specific amino acid called leucine acts as the “on switch” for that process. You need roughly 2 to 3 grams of leucine in a meal to fully activate muscle protein synthesis. Most high-quality protein sources hit that threshold naturally at the 20 to 40 gram range. A chicken breast, a scoop of whey protein, or a cup of Greek yogurt with some eggs will get you there without much thought.
This leucine threshold is the reason protein quality matters, not just quantity. Whey protein is naturally rich in leucine, which is why it’s long been the go-to post-workout option. Plant-based proteins tend to contain less leucine per gram, which means they stimulate less muscle building at the same dose. However, recent research found that when a plant-based protein blend was supplemented with extra leucine to match the leucine content of whey, it stimulated muscle building at a comparable rate in young men and women. If you eat plant-based, choosing blends with added leucine or simply eating a slightly larger serving can close the gap.
Can Your Body Use More Than 30 Grams at Once?
You’ve probably heard that your body can only “use” 20 to 30 grams of protein per meal and the rest goes to waste. That’s an oversimplification. It’s true that muscle protein synthesis appears to max out around 20 to 25 grams of high-quality protein in younger adults. But the amino acids above that threshold aren’t simply discarded. Some are oxidized for energy, yes, but others are still used for tissue-building purposes throughout the body.
So eating 50 grams of protein in one sitting isn’t wasted. You’ll still digest and absorb all of it. The muscle-building signal just doesn’t scale linearly beyond that 20 to 40 gram sweet spot. For practical purposes, you’ll get more total muscle-building benefit from four 35-gram servings spread across the day than from two 70-gram servings.
The “Anabolic Window” Is Wider Than You Think
The old advice to chug a protein shake within 30 minutes of your last set has been significantly challenged. The urgency of post-workout protein depends almost entirely on when you last ate before training.
If you had a solid meal one to two hours before your workout, that food is still being digested and supplying amino acids to your muscles during and after training. In that scenario, rushing to get protein in immediately after isn’t necessary. Your next regular meal, whether it’s right away or an hour or two later, is enough to support recovery and growth.
The timing becomes more important if you trained in a fasted state or if your last meal was more than three to four hours before your workout. In that case, eating at least 25 grams of protein relatively soon after training helps reverse muscle breakdown and kickstart repair. A practical rule: your pre-workout and post-workout meals should fall within roughly three to four hours of each other, assuming a typical 45 to 90 minute training session. If your pre-workout meal was at noon and you finish training at 1:15, eating by 3:30 or 4:00 is fine.
Total Daily Protein Outweighs Timing
This is the single most important takeaway. Research comparing groups that consumed protein at different times relative to their workouts has found no significant differences in muscle mass or strength gains, as long as total daily protein intake was the same. Both groups improved equally. Any effect of post-workout timing, if it exists, appears to be minor compared to simply getting enough protein across the entire day.
For people who strength train, that daily target is roughly 1.6 to 2.2 grams per kilogram of body weight. A 170-pound person should aim for about 123 to 170 grams of protein per day, spread across at least four meals. Getting that total right is the foundation. Post-workout timing is a secondary optimization that can play a useful role in recovery, especially for endurance exercise and high-volume resistance training, but only after the daily total is accounted for.
Adjustments for Older Adults
As you age, your muscles become less responsive to protein, a phenomenon researchers call anabolic resistance. This means older adults generally need more protein per serving to get the same muscle-building response that younger people get from a smaller dose. While a 25-year-old might max out muscle protein synthesis at 20 grams, someone over 60 often needs 35 to 40 grams per meal to achieve a comparable effect.
Daily totals matter here too. Research on older adults doing strength training has shown benefits at intakes up to 1.6 g/kg of body weight per day, with no adverse effects over periods longer than four months. If you’re over 60 and strength training, prioritizing a higher protein intake at each meal, including the one after your workout, becomes especially worthwhile.
Practical Post-Workout Meals
You don’t need a supplement to hit these targets. A scoop of whey protein delivers about 25 grams and is convenient, but whole foods work just as well. Four ounces of chicken breast gives you roughly 35 grams. Two large eggs plus a cup of Greek yogurt gets you to about 30 grams. A can of tuna provides around 30 grams. For plant-based options, a tofu scramble with a side of lentils or a protein shake made from a pea-rice blend with added leucine can reach the same range.
Pairing protein with carbohydrates after a workout helps replenish glycogen stores, which matters if you train frequently or do endurance work. But for the specific goal of muscle building, the protein itself is the key variable. Hit 0.4 to 0.5 g/kg in your post-workout meal, keep your total daily intake at 1.6 g/kg or above, and don’t stress about the stopwatch.