April 30, 2026

How Your Body Recovers After a Marathon – And What I Learned Along the Way

By Niamh Bunyan, Senior Physiotherapist & London Marathon Finisher

This year’s London Marathon didn’t go to plan and it ended up teaching me more about recovery than any “perfect” training block ever could.

Training was far from ideal. Life got in the way, and a few weeks before race day I was dealing with being ill. So the goal shifted – no PB, just getting to the start line and through it. 

That said, I didn’t take that decision lightly. 

Wearing my Garmin allowed me to track how I was recovering – making sure my heart rate had returned to normal and my sleep was back on track. I also sought professional advice to confirm I was fit to run. There’s a difference between pushing yourself and putting your health at risk. 

What made the biggest difference? Accountability. 

I had weekly check-ins with colleagues, alongside a RunFit assessment pre-race, plus dry needling and sports massage to stay on top of a few niggles (physio’s need accountability too!). 

It meant I showed up on race day pain-free, and honestly, it stood to me after. I felt surprisingly good… almost like I hadn’t run a marathon. 

Not going to lie though, that post-run pint in the pub might have been the real recovery.

What’s actually happening in your body post-marathon? 

Running 26.2 miles places a huge amount of stress on your body – not just muscles, but energy systems, joints, and even your nervous system. 

Here’s what to be aware of (and what actually helps):

1) Your muscles need time to repair

A marathon causes small amounts of muscle damage, which is why soreness typically peaks 24–72 hours later. 

Interestingly, mine was minimal this time, likely down to going in well-managed rather than perfectly trained. 

What helps: 

• Gentle movement (walking over complete rest)  
• Light mobility work  
• Avoid aggressive stretching too early  
• Get checked if pain feels sharp or extreme

2) Your energy stores are depleted

Your glycogen stores take a big hit, which is why post-marathon fatigue and hunger can feel intense. 

What helped me: 

• A very enthusiastic breakfast buffet the next day  
• Medal Monday in London (protein shakes, cookies, pizza – all covered)  
• Then focusing on balanced meals, hydration, and prioritising sleep  
• I also kept things simple with supplements I regularly use  (creatine, vitamin C, Vitamin D, magnesium, Omega-3, and electrolytes) mainly to support hydration, recovery, and overall immune function after being run down pre-race.

3) Joints and tendons need longer to recover

Even when muscle soreness settles, tendons and joints are still adapting after thousands of strides. 

This is where people often come unstuck – returning to training too quickly. 

What I did: 

• Day 2: 20 mins easy cycling & refuelling 
• Day 3: another short cycle & Pilates 

Low-impact movement helps without overloading recovery.

4) Keep things moving (but don’t rush it) 

Complete rest isn’t always the answer – controlled movement supports circulation and recovery. 

The day after the marathon, I took the day off work, and was on and off a Lime bike running a few errands (surprisingly effective), and also used sauna and cold plunge to help relax and reset. 

The key is keeping it low intensity and consistent. 

5) Fatigue isn’t just physical 

There’s often a mental dip after a big race, regardless of how it went. 

For me, this year was more about resilience than performance. Adjusting expectations and still finishing made it feel even more meaningful. 

When should you run again? 

For most runners: 

• Week 1: Rest, walking, mobility  
• Week 2: Easy running if you feel ready  
• Week 3+: Gradual return to training  

If you’re unsure, getting a physio involved early can help guide that return and pick up on anything that might turn into an injury. 

Final thought 

This marathon wasn’t about a PB. It was about adapting, listening to my body, and having the right support around me. 

Recovery isn’t about doing everything perfectly. It’s about doing the right things consistently.