PROTEIN FOR ATHLETES OVER 50: THE COMPLETE GUIDE

Protein for athletes over 50 is one of the best-studied questions in sports nutrition, and the research is clear on one point: older muscle responds less to the same amount of protein than younger muscle does. How much that should change what you eat is where the studies start to disagree. This guide sets out what they measured, at the strength they actually have, next to how I cook for training in my own kitchen.

Where I'm coming from: I'm a Marine veteran and an endurance athlete with more than 300 races behind me, and I wrote The High Protein Cookbook for Athletes Over 50. I'm not a dietitian or a physician. What follows is what the published studies and guidelines say, and what the cookbook does. When a number is a guideline, a study finding or a choice from my own kitchen, I'll say which.

Why Protein Works Differently After 50

Researchers call it anabolic resistance: older muscle builds less new protein from the same meal.

• The dose it takes. In a pooled analysis of tracer studies in healthy men, Moore and colleagues (2015) found muscle protein synthesis leveled off at about 0.40 g of protein per kg of body weight in a meal for men around 71, compared with 0.24 g/kg for men around 22. By body weight the difference was borderline (p = 0.055); by lean mass it was clear.
• The size of the gap. Wall and colleagues (2015) pooled data from older and younger men and found that after eating protein, muscle protein synthesis was 16% lower in the older men, while resting rates did not differ.
• After lifting. In 37 men averaging 71, Yang and colleagues (2012) found that after a resistance exercise session, 40 g of whey raised muscle protein synthesis more than 20 g did. The authors contrast this with young adults, whose response levels off around 20 g.

These are short laboratory studies, almost entirely in healthy men, measuring muscle protein synthesis over hours, not muscle gained over months. They explain why the guidelines for older adults are higher than the standard adult figure. They don't tell anyone exactly how much to eat.

How Much Protein a Day: What the Guidelines Say

• PROT-AGE Study Group (2013), people over 65: an average daily intake "at least in the range of 1.0 to 1.2 g" per kg of body weight, and at least 1.2 g/kg for those who are exercising and otherwise active. It makes an exception for people with severe kidney disease who are not on dialysis.
• ESPEN (2014), healthy older people: at least 1.0 to 1.2 g per kg a day, along with daily resistance and aerobic exercise.
• International Society of Sports Nutrition (2017), exercising adults of any age: 1.4 to 2.0 g per kg a day "is sufficient for most exercising individuals," with 20 to 40 g per serving depending on age.

There is no separate guideline for masters athletes. A 2025 scoping review (Franzke) found masters athletes in the studies ate 1.0 to 1.9 g/kg a day and concluded that recommendations for them "are non-existent or speculative." To see what each guideline works out to for your weight, use the free Protein Calculator for Adults Over 50.

Protein With Strength Training: What the Trials Found

This is where the meta-analyses disagree, and the disagreement is worth seeing.

• Morton and colleagues (2018): 49 randomized trials, 1,863 adults of all ages. Adding protein to resistance training increased one-rep-max strength by 2.49 kg and fat-free mass by 0.30 kg on average. The benefit for fat-free mass got smaller with age, and protein beyond about 1.6 g/kg a day added no further gain.
• Liao and colleagues (2017): 17 randomized trials, average age 73. Protein plus training improved lean mass and leg strength more than training alone (standardized mean differences 0.58 and 0.69).
• Finger and colleagues (2015): 9 randomized trials, 462 adults aged 61 to 79. Protein increased fat-free mass slightly but had no significant effect on muscle mass or strength. The authors rated the study quality low.
• Nunes and colleagues (2022): 74 randomized trials. With resistance training, more protein produced a modest lean-mass gain, and in adults 65 and older that gain was significant at intakes of 1.2 to 1.59 g/kg a day.

Taken together, extra protein alongside lifting was associated with a little more lean mass, the effect on strength was inconsistent, and age tended to shrink the benefit. The training did most of the work. These were mostly untrained or recreationally active adults; I could not find a protein trial in trained masters athletes. For the training side, see Strength Training After 50.

Spreading Protein Across the Day

The idea that you should split protein evenly across meals is popular, and the evidence for it is weaker than its popularity.

• In a small 8-week randomized trial in 14 older adults (Kim 2018), an even split versus a dinner-heavy split made no difference to lean mass, strength or muscle protein synthesis.
• In the Quebec NuAge study of older adults aged 67 to 84 (Farsijani 2016 and 2017), a more even split went with more lean mass and higher strength scores at each point, but not with slower loss of muscle or strength over two to three years. Those are associations, not proof.

More in Protein Distribution After 50.

Timing and Protein Before Bed

A 2013 meta-analysis of timing studies (Schoenfeld) found that once total protein intake was accounted for, eating protein close to training had no clear effect on strength or muscle size. Total daily intake was the strongest predictor. The abstract doesn't report participants' ages, so it isn't evidence specific to older adults.

Before sleep, a randomized trial in 48 men averaging 72 (Kouw 2017) found that 40 g of casein raised overnight muscle protein synthesis compared with a placebo, while 20 g did not. That's an overnight laboratory measure, not muscle gained over months. More in Pre-Sleep Protein After 50.

Plant or Animal Protein?

• In 9 studies comparing soy with animal protein during resistance training (Messina 2018), gains in strength and lean mass did not differ.
• In 16 randomized trials (Lim 2021), plant and animal protein produced similar absolute lean mass and strength, and adults under 50 gained more lean mass with animal protein.
• In a 2025 meta-analysis (Reid-McCann), plant protein was associated with slightly less muscle mass overall, but in adults 60 and older there was no significant difference. Soy matched milk protein; other plant proteins did worse.

Short laboratory studies favor whey: in 48 men averaging 74 (Pennings 2011), 20 g of whey raised muscle protein synthesis more than casein did, in step with how fast it raised blood leucine. The longer training trials above didn't show that edge turning into more muscle.

Is High Protein Safe for Your Kidneys?

In a 2018 meta-analysis of 28 randomized trials in 1,358 adults without kidney disease (Devries), higher-protein diets did not change kidney function over the trials' length compared with lower-protein diets. That finding is for people with healthy kidneys. PROT-AGE makes an exception for people with severe chronic kidney disease who are not on dialysis, who may need to limit protein. If you have kidney disease, diabetes or another medical condition, your physician or a registered dietitian should set your target.

Putting It on the Plate

The High Protein Cookbook for Athletes Over 50 is built around a simple standard: with the ingredients as written, every main meal has at least 30 grams of protein per serving and every breakfast or light meal at least 25, estimated from USDA data. That's the book's choice, not a research threshold. Here's one hard-training day from its pages:

• Breakfast: Overnight Oats with Greek Yogurt, Chia and Pumpkin Seeds, 28 g of protein.
• Lunch: Chicken, Rice and Pinto Bean Bowl, 50 g.
• Dinner: Shrimp and Peppers over Quinoa, 41 g.

That's 119 g from three meals, per the book's per-serving estimates. The free Protein After 50 Cheat Sheet below lists the protein in 29 everyday foods from the USDA database, with this sample day. If calories matter more to you than protein, Quick Easy Healthy Meals is a 14-day plan of 20-minute recipes at about 2,000 calories a day.