Recovering After a Half Marathon
Racing a half marathon is hard on the body. Harder than you might expect.
After the race, your immune system is stressed, inflammation is elevated, stress hormones are high, and there are signs of muscle breakdown. Your kidneys are under stress too. All of this is normal but it takes time to resolve. Here's what the research tells us about how to handle the recovery after a half marathon:
First 3 Hours
Your body is in its peak stress state at this point. Markers of inflammation, immune activation, muscle breakdown, and stress hormones are all at their highest point.
What to do about it:
Hydrate immediately. Your kidneys are working to clear muscle breakdown products. Drink fluids as soon as you can. ¹
Eat within 30–60 minutes. You need carbohydrates and protein to refuel to start with muscle recovery. Even if you're not hungry, eat something. ¹
Hours 3–48
In the first 48 hours, general inflammatory markers are still elevated, and markers of muscle damage and cardiac stress remain high.
This is also when tendons are most actively repairing. Tendon collagen synthesis peaks around 24 hours after exercise and stays elevated for about 3 days. ² Your tendons are recovering during this period.
Sleep is important. This is when tissue repair happens. ¹ Try to prioritize it just like you did before the race.
Move, but don't start training yet. Easy walking, light stretching, and low-intensity yoga are all examples of active recovery activities that can be done safely during this period. Structured running is not recommended yet. Your body needs a rest day, as cardiac and kidney stress markers are still elevated. ¹
Hold off on cold therapy for now. Inflammation is still present and actively driving repair during this window. Cold therapy can interfere with that process. Save it for days 2–7. ¹
Days 2–7
Most runners start feeling better during this window, but that doesn't mean everything is back to normal yet. Muscle damage markers are still elevated at 48 hours, even when soreness fades. Cardiac stress markers are normalizing but not fully resolved.
Tendons lag even further behind. Research shows that tendon collagen remodeling continues for days after a significant loading event. ² If you push too hard too soon, you could be hurting your future training block more than you're helping it.
How you feel is not always a reliable guide. Muscle and tendon recovery happen behind the scenes even if you are starting to feel better. ¹ ²
Cold therapy is fine here. The inflammatory peak has passed, so ice baths or cold showers won't interfere with repair signaling at this point. They'll also help with the muscle soreness that almost every runner experiences after a race. ¹
Hold off on hard training until at least day 5–7. This is supported by both the cardiac and tendon recovery data. ¹ ²
If this race was an exceptionally difficult one, add a few extra easy days. Less-trained runners often have more pronounced and prolonged stress responses across these markers of physiologic stress. ¹
If you have a tendon issue, be especially conservative. Racing loads tendons far beyond what normal training does. Too-fast return to speed work or high mileage is one of the most common triggers for tendon flare-ups after a race. ²
After 7 Days
This is when we start building again.
We ease back in with shorter, easier runs and add volume and intensity gradually. A simple approach is the Reverse Taper — run the same workouts as your race week, but in reverse order.
If you have a tendon issue, check in before ramping back up. The tendon may still be remodeling even after you feel fully recovered.
Brief Summary:
The half marathon results in muscle, tendon, cardiac, and kidney stress. This lasts for 3–7 days depending on the runner.
Eat and hydrate right after your race
Engage in gentle/easy movement the first few days after the race
Even when you start feeling good, these markers of physiologic stress are still present for up to 5–7 days
Ease into light training after 5–7 days, with harder efforts beyond day 7
References
¹ Niemelä M, Kangastupa P, Niemelä O, Bloigu R, Juvonen T. Acute Changes in Inflammatory Biomarker Levels in Recreational Runners Participating in a Marathon or Half-Marathon. Sports Medicine – Open. 2016;2:21. doi:10.1186/s40798-016-0045-0
² Magnusson SP, Langberg H, Kjaer M. The pathogenesis of tendinopathy: balancing the response to loading. Nature Reviews Rheumatology. 2010;6(5):262–268. doi:10.1038/nrrheum.2010.43
