Endurance athletes need protein for repair: but the worst thing after a hard long run is a thick, milky shake sloshing around your stomach. The picks below favour fast-absorbing whey isolate and the new generation of clear whey (juice-like texture, perfect for hot-weather recovery), plus plant blends for athletes who prefer dairy-free. All clean, all easy on the gut, all ranked by value across 12 US retailers.
Endurance athletes don't need lifter-level protein: but they need more than the sedentary RDA. The IOC and ACSM converge on 1.4 to 1.8 grams per kg of bodyweight per day for runners, with the upper end during heavy training blocks, ultra prep, or while in a calorie deficit.
Aim for ~20–25g of protein within 30–60 minutes of a hard or long session: paired with carbs at a 1:3–4 ratio for optimal glycogen replenishment. Clear whey shines here: it pours like a sports drink, sits well in a hot stomach, and delivers 20g of fast-absorbing whey hydrolysate in 250ml of water.
Not "need": but most runners under-eat protein, especially during heavy weeks. A 20–25g whey isolate or clear whey shake immediately after a long run accelerates muscle repair, blunts soreness, and is far easier to digest than a chicken breast at the mile-20 finish line.
Clear whey wins for hot-weather and post-long-run recovery: it's whey hydrolysate that pours like a sports drink in water, with no milky heaviness. Regular whey blends and isolates win for value-per-gram and protein density when you're at home, not gasping for cold liquid.
After. Pre-run protein can sit heavy in the gut, especially before tempo or race efforts. The exception is a small (10g) shake 60+ minutes before an easy run if you trained fasted that morning. Post-run, aim for protein + carbs within an hour for the cleanest recovery curve.
Whey concentrate can: it has ~4g of lactose per scoop and a heavier texture. Whey isolate (under 1g lactose) and clear whey (zero lactose) almost never cause GI issues. Plant-based pea+rice blends are also gentle and a great call for runners with any dairy sensitivity.