Mavr Sports Nutrition Team
September 2, 2026. 12 min read.
Runners have an odd relationship with protein. The lifting world treats it as the whole sport; endurance culture treats it as somebody else’s nutrient and spends its attention on carbohydrate. Both are wrong in useful ways. Carbohydrate is what fuels the run, but protein is what allows you to keep doing runs, and the research on endurance athletes has landed on requirements very close to those of strength athletes.
That leaves the practical question: is a tub of powder a genuinely useful piece of equipment, or an expensive way to drink something you could have eaten? The honest answer is that it depends entirely on where your current protein is, and specifically on when in the day it arrives.
The ACSM/Academy of Nutrition and Dietetics position stand and the International Society of Sports Nutrition converge on the same range: 1.4 to 2.0 g of protein per kilogram of body weight per day for athletes, with the top of that range appropriate during heavy training, injury, or an energy deficit. The general-population RDA of 0.8 g per kg is a floor for avoiding deficiency, not a target for someone running 50 km a week.
| Body weight | Daily protein (1.4 g/kg) | Daily protein (1.8 g/kg) | Per feeding (4 meals) |
|---|---|---|---|
| 55 kg / 121 lb | 77 g | 99 g | 20 to 25 g |
| 65 kg / 143 lb | 91 g | 117 g | 23 to 30 g |
| 75 kg / 165 lb | 105 g | 135 g | 26 to 34 g |
| 85 kg / 187 lb | 119 g | 153 g | 30 to 38 g |
Notice the last column, because it is where the real problem lives. Most runners hit a respectable daily total and still fail, because the total arrives in one enormous evening meal. Muscle protein synthesis responds to individual feedings, not to a 24-hour sum. A day of 8 g at breakfast, 15 g at lunch, and 75 g at dinner totals 98 g and stimulates repair roughly once.
The amino acid leucine is the trigger. A feeding needs roughly 2.5 to 3 g of leucine to switch muscle protein synthesis on properly, and how much total protein that takes depends on the source.
Whey isolate or concentrate
Approx. protein for a full response20 to 25 g
NotesHighest leucine density, fastest absorption
Milk, Greek yoghurt, skyr
Approx. protein for a full response25 to 30 g
NotesWhey plus casein, excellent whole-food option
Eggs, chicken, fish, beef
Approx. protein for a full response25 to 30 g
NotesComplete and well tolerated, slower to prepare
Soy protein
Approx. protein for a full response25 to 30 g
NotesThe strongest single plant source
Pea and rice blend
Approx. protein for a full response30 to 40 g
NotesComplementary amino acid profiles; blend beats either alone
Pea protein alone
Approx. protein for a full response35 to 40 g
NotesLower methionine, so a blend is preferable
| Source | Approx. protein for a full response | Notes |
|---|---|---|
| Whey isolate or concentrate | 20 to 25 g | Highest leucine density, fastest absorption |
| Milk, Greek yoghurt, skyr | 25 to 30 g | Whey plus casein, excellent whole-food option |
| Eggs, chicken, fish, beef | 25 to 30 g | Complete and well tolerated, slower to prepare |
| Soy protein | 25 to 30 g | The strongest single plant source |
| Pea and rice blend | 30 to 40 g | Complementary amino acid profiles; blend beats either alone |
| Pea protein alone | 35 to 40 g | Lower methionine, so a blend is preferable |
This is the entire technical case for protein powder, and it is a modest one: 25 g of protein is trivially easy to drink and moderately annoying to eat at 6:40 a.m. before a commute. If your breakfast is toast and coffee, a shake fixes a real gap. If your breakfast is already three eggs, it fixes nothing.
Whey isolate
Digestion speedFast, peaks in about an hour
Best usedStraight after a hard session
Watch out forCosts more than concentrate for a marginal benefit
Whey concentrate
Digestion speedFast
Best usedEveryday use, best value
Watch out forContains lactose; a problem for some guts
Casein
Digestion speedSlow, releases over hours
Best usedBefore bed, especially after evening training
Watch out forThick texture; unpleasant in water for some
Pea and rice blend
Digestion speedModerate
Best usedDairy-free everyday use
Watch out forNeeds a slightly larger scoop for the same effect
Soy isolate
Digestion speedModerate
Best usedDairy-free, single-source option
Watch out forStrong flavour in unflavoured versions
Collagen
Digestion speedFast
Best usedTendon and connective-tissue support only
Watch out forNot a complete protein; must not count as your protein source
| Type | Digestion speed | Best used | Watch out for |
|---|---|---|---|
| Whey isolate | Fast, peaks in about an hour | Straight after a hard session | Costs more than concentrate for a marginal benefit |
| Whey concentrate | Fast | Everyday use, best value | Contains lactose; a problem for some guts |
| Casein | Slow, releases over hours | Before bed, especially after evening training | Thick texture; unpleasant in water for some |
| Pea and rice blend | Moderate | Dairy-free everyday use | Needs a slightly larger scoop for the same effect |
| Soy isolate | Moderate | Dairy-free, single-source option | Strong flavour in unflavoured versions |
| Collagen | Fast | Tendon and connective-tissue support only | Not a complete protein; must not count as your protein source |
Collagen deserves a specific warning because it is heavily marketed to runners. It is low in leucine and lacks tryptophan, so it does not support muscle repair the way whey or a plant blend does. There is genuinely interesting evidence for gelatin or collagen with vitamin C taken about an hour before loading for tendon and ligament health, but that is an additional supplement, not a substitute for protein.
Casein before bed is the one endurance-specific use case worth knowing. If you train in the evening, eat at 20:00, and sleep at 23:00, you have an eight-hour overnight gap right after the session that damaged the muscle. A slow protein of 30 to 40 g before bed raises overnight synthesis rates. Milk-based Greek yoghurt does the same job with food.
The 30-minute anabolic window turned out to be much wider than the original studies suggested; muscle stays sensitised to protein for many hours after a session. Getting 25 g of protein within a couple of hours of a hard run is entirely sufficient. Sprinting to a shaker before you finish your cool-down is not.
Carbohydrate is the nutrient with the genuinely tight clock. If you train again within about 24 hours, and especially within 8 hours, glycogen replacement in the first few hours matters a great deal. That is why a recovery shake for a runner should almost never be protein alone. A 3:1 or 4:1 carbohydrate-to-protein ratio after a long or hard run is the shape that fits endurance training, and it is one of the most common mistakes to copy the gym’s protein-only habit.
Easy 40 min run before breakfast
What to takeJust eat breakfast
WhyNo special intervention needed
Hard intervals, next meal 3+ hours away
What to take25 g protein plus 60 to 80 g carbohydrate
WhyBridges the gap and restarts glycogen replacement
Long run, racing or training again tomorrow
What to takeCarbohydrate-dominant recovery drink plus 25 g protein
WhyGlycogen is the limiting factor, not protein
Evening session, bed in 2 to 3 hours
What to takeNormal meal, then 30 to 40 g casein or Greek yoghurt
WhyCovers the overnight gap
Low-appetite after a very hard effort
What to takeLiquid calories with protein
WhyDrinking works when eating does not
| Situation | What to take | Why |
|---|---|---|
| Easy 40 min run before breakfast | Just eat breakfast | No special intervention needed |
| Hard intervals, next meal 3+ hours away | 25 g protein plus 60 to 80 g carbohydrate | Bridges the gap and restarts glycogen replacement |
| Long run, racing or training again tomorrow | Carbohydrate-dominant recovery drink plus 25 g protein | Glycogen is the limiting factor, not protein |
| Evening session, bed in 2 to 3 hours | Normal meal, then 30 to 40 g casein or Greek yoghurt | Covers the overnight gap |
| Low-appetite after a very hard effort | Liquid calories with protein | Drinking works when eating does not |
Powder is a convenience, and convenience is worth paying for only when it removes a real obstacle. Skip it if your day already contains three feedings of 25 g or more, if you eat dairy and enjoy Greek yoghurt or skyr, if you cook most meals, or if you are eating at a normal energy level and recovering fine. Buy it if breakfast is chronically protein-free, if you finish sessions far from food, if you are vegan and struggling to reach 1.6 g per kg, or if your appetite disappears after long runs.
And a caution worth stating plainly: adding protein does not fix under-fuelling. Runners who feel flat, sleep badly, get repeatedly ill, and stop improving are usually short on total energy and carbohydrate, not on protein. Protein powder is a very poor treatment for that problem and a very effective way to feel like you have done something about it.
No runner needs it, but many benefit from it. The requirement is 1.4 to 2.0 g per kg of body weight per day spread over three to five feedings. If you already reach that from food, powder adds nothing. If your breakfast contains almost no protein, a shake is the simplest fix available.
For most runners, a plain whey concentrate with roughly 75 to 80 g protein per 100 g and third-party batch testing. If you avoid dairy, a pea and rice blend at a slightly larger dose does the same job. Beyond that, price and flavour matter more than brand.
About 0.3 to 0.4 g per kg of body weight, which is 20 to 30 g for most runners. After a long or hard run, pair it with two to four times as much carbohydrate, because glycogen replacement is the time-sensitive part.
Whey is more leucine-dense, so it triggers the same response at a smaller dose. A pea and rice blend at 30 to 40 g closes the gap. Neither has a meaningful advantage for endurance performance once the dose is matched.
Usually not. Before a run you want carbohydrate and a mostly empty stomach. Protein is slower to digest and offers no fuel benefit for the session ahead. Save it for after, or for a meal several hours before.
Not as your protein source. Collagen is an incomplete protein, low in leucine and missing tryptophan, so it does not support muscle repair. It may help tendons and ligaments when taken with vitamin C around an hour before loading, but treat it as a separate supplement.
General guidance for healthy adults, not medical advice. Talk to a doctor or registered dietitian if you have a health condition, take medicines or have special dietary needs.
Mavr tracks protein per meal rather than per day, so you can see the breakfast gap that a shake is actually meant to fix.
Ask Kai, the coach in the app