Muscle Damage and Inflammation After Running a Marathon

Running a marathon can be a very stressful physical task. Unlike other sports like cycling or swimming, the impact on the body can be much more severe. In cycling, the bike is the physical contact with the ground and almost all the effort is concentric. And in swimming all the muscular actions are concentric, except for the turns.

So it should be clear that running in particular, and marathons specifically, is more taxing on the body.

But how hard is a marathon? And how stressed is the body after running 26.2 miles?

A recent study looked to see the impact of intense physical exercise, i.e. running a marathon, on certain biomarkers and the time for these markers to return to normal.

Four biomarkers were analyzed before, at the end, and 24, 48, 96 and 144 hours after the race. The biomarkers they looked at were:

* lactate dehydrogenase - an indicator of tissue damage

* creatine kinase - an indicator of muscle damage

* high-sensitivity troponin - an indicator of myocardial damage

* C-reactive protein - an indicator of inflammation

86 runners participated in the study, including men and women. Ages ranged from 30-44 years, with BMIs between 15 and 26 and could complete a marathon between 3 and 4 hours.

What they found is that:

* levels of biomarkers decreased with longer race times i.e. running faster is more stressful and therefore we see higher levels of damage and inflammation with faster times

* greater energy expenditure is associated with higher levels of these biomarkers

As for how long it took to took to return to pre-marathon, i.e. normalized, levels ranged from 96 hours (hs-troponin), to 144 hours (creatine kinase), and 192 hours for lactate dehydrogenase and C-reactive protein. 

In other words, markers of heart damage returned to normal first whereas tissue damage and inflammation took the longest to come back down to normal.

It would be interesting to see the experiment repeated but to investigate the differences in creatine kinase between those who included resistance training in their preparation for the marathon, and those that didn't.

As well, for those planning to run a marathon, have a recovery plan in place. For example, knowing the inflammation will peak 24 hours post marathon, and stay elevated for 9 days after the race, we should have a plan to address this. This would include non-impacting light activity, hydration and an increased consumption of fruits and vegetables.

Lastly, if your goal is to compete, and not just complete, a marathon, understand this is more stressful on the body. Don't assume that running a 2:30 marathon requires the same attention to recovery as a 3:30 marathon.  

Bernat-Adell, María D.¹; Collado-Boira, Eladio J.¹; Moles-Julio, Pilar¹; Panizo-González, Nayara²; Martínez-Navarro, Ignacio³; Hernando-Fuster, Bárbara⁴; Hernando-Domingo, Carlos⁵ Recovery of Inflammation, Cardiac, and Muscle Damage Biomarkers After Running a Marathon, Journal of Strength and Conditioning Research: March 2021 - Volume 35 - Issue 3 - p 626-632 doi: 10.1519/JSC.0000000000003167