If you work out regularly, you need roughly twice the protein of someone who doesn’t. The general recommendation for active people is 1.2 to 2.0 grams of protein per kilogram of body weight per day, which works out to about 0.5 to 0.9 grams per pound. Where you land in that range depends on the type of training you do, whether you’re trying to lose fat, and your age.
The standard dietary recommendation for all adults is 0.8 grams per kilogram per day, but that number is set to prevent deficiency, not to support muscle repair or growth. If you’re putting stress on your muscles through any kind of structured exercise, that baseline isn’t enough.
Protein Needs by Training Type
Your protein target shifts depending on how you train. Strength training causes more direct muscle damage than cardio, so it demands more raw material for repair and growth. Endurance exercise like running or cycling still increases protein needs, just for different reasons: prolonged activity burns through amino acids for fuel, and your body needs extra protein to maintain and build the cellular machinery that improves aerobic performance.
For strength and resistance training, the range that best supports muscle growth is 1.6 to 2.2 grams per kilogram per day. A simpler rule of thumb: aim for about 0.7 grams per pound of body weight. So a 180-pound person lifting weights would target roughly 126 grams of protein daily. For endurance athletes (runners, cyclists, swimmers doing sustained training), 1.4 to 1.8 grams per kilogram is the typical range. If you do a mix of both, landing somewhere around 1.6 grams per kilogram covers most bases.
Why Losing Fat Changes the Math
When you’re eating fewer calories than you burn, your protein needs go up, not down. In a calorie deficit, your body is more likely to break down muscle tissue for energy unless you give it enough protein to protect that lean mass. This is one of the most common mistakes people make when trying to lose weight while working out.
During a cut, bumping protein intake to 0.8 to 1.0 grams per pound of body weight helps preserve muscle. Research on athletes in weight-class sports and physique competitors found that intakes of 2.3 to 3.1 grams per kilogram of fat-free mass best preserved lean tissue under calorie restriction. You don’t need to calculate your fat-free mass precisely. The practical takeaway is that if you’re dieting and training, err toward the higher end of any protein recommendation you follow.
How to Spread Protein Across the Day
Total daily protein matters most, but how you distribute it across meals makes a real difference. Your muscles can only ramp up their repair and growth processes so much in response to a single dose of protein. Research consistently shows that meals containing 30 to 45 grams of protein produce the strongest muscle-building response, and eating at that level two or three times a day outperforms the common habit of skimping at breakfast and lunch and loading up at dinner.
One study compared people who ate about 30 grams of protein at each of three meals against people who ate the same total amount but skewed heavily toward dinner (10 grams at breakfast, 15 at lunch, 65 at dinner). The evenly distributed group built more muscle protein over 24 hours. This doesn’t mean eating more than 45 grams in a sitting is wasted, but the first 30 grams or so is where the biggest benefit comes from. If you’re eating 150 grams a day, splitting it roughly into four meals of 35 to 40 grams is more effective than two big meals and two tiny ones.
Post-Workout Timing Is More Flexible Than You Think
The idea that you need to chug a protein shake within 30 minutes of your last set has been overstated. The so-called anabolic window, the period when your muscles are primed to absorb and use protein, likely extends to 5 or 6 hours around your workout, not just the 30 to 60 minutes that gym culture has popularized.
The real variable is whether you ate before training. If you worked out fasted (first thing in the morning with no food), getting protein soon after matters more because your body has been without amino acids for hours. If you had a meal containing protein within a couple hours before your session, there’s no urgency to eat again immediately. A study tracking people who took protein either before or after their workouts for 10 weeks found no meaningful difference in muscle or strength gains between the two groups.
A reasonable target for protein around your training session (before, after, or split between both) is 20 to 40 grams.
Not All Protein Sources Are Equal
Protein quality matters because different foods contain different proportions of the essential amino acids your muscles need. Animal-based proteins like dairy, eggs, meat, and fish score highest for quality because they contain all essential amino acids in high concentrations and are easy for your body to digest. Milk protein, for instance, scores well above the threshold for “high quality” by international standards. Wheat protein scores quite low on its own, and pea protein falls in the middle.
One amino acid in particular, leucine, acts as a trigger that tells your muscles to start building new protein. You need roughly 2 to 3 grams of leucine per meal to fully activate that signal. About 25 to 30 grams of a high-quality animal protein delivers this amount naturally. Plant proteins tend to contain less leucine per gram, which is one reason vegetarian and vegan athletes often benefit from higher total protein intake, around 2.0 grams per kilogram per day, or from combining multiple plant sources to cover any gaps in amino acid profiles.
How Protein Needs Change With Age
As you get older, your muscles become less responsive to the protein you eat. This phenomenon, sometimes called anabolic resistance, means the same meal that efficiently stimulates muscle repair in a 25-year-old produces a weaker response in a 55-year-old. Nearly half of all the protein in your body is found in muscle, and muscle mass naturally declines with age, making adequate protein intake even more important for older adults who exercise.
Older adults who are active generally need at least 1.2 grams per kilogram daily, and those doing serious resistance or endurance training should aim for 1.6 grams per kilogram or more to achieve adaptations comparable to younger athletes. Some researchers recommend that older adults who are also trying to build strength consume up to 1.6 grams per kilogram, which for a 180-pound person comes out to roughly 130 grams per day.
Is There a Safety Ceiling?
For healthy people, high-protein diets are not known to cause kidney damage or other medical problems. That concern comes from studies on people who already have kidney disease, where the kidneys struggle to clear the waste products from protein metabolism. If your kidneys are healthy, intakes in the 1.6 to 2.2 grams per kilogram range are well within the range that athletes have used safely for decades.
That said, consistently going above 2.0 grams per kilogram of total body weight without a specific reason (like an aggressive fat-loss phase) may not add much benefit and could displace other important nutrients from your diet. For most people who work out, staying in the 1.4 to 2.0 grams per kilogram range covers the vast majority of needs. The exceptions, where going higher makes sense, are serious calorie deficits, high-volume resistance training programs, and plant-based diets where protein quality requires compensation through higher quantity.