Updated 05/20/24 9:56 PM

Health and Performance:
Marathon Recovery Nutrition

Running a marathon places high demands on three systems to supply energy for muscle contraction.

In the first 30 seconds, the phosphagenic system uses creatine phosphate. For the next 3 minutes, the anaerobic system uses glycogen without oxygen. And after 3 minutes of running, the aerobic system dominates using fat, glycogen, and protein for energy.

After a marathon, your body is not ready to process nutrients and replenish depleted energy stores until multiple functions are restored and repair begins. Blood markers for heart, liver, kidney and muscle damage may be elevated for a week.

For 36 hours after a marathon, Excess Post Exercise 02 Consumption (EPOC) consumes energy to normalize body temperature, hormone levels, electrolytes (calcium/sodium/potassium in heart/muscle/nerve cells), plus 40 metabolites and begin tissue repair.

Catabolic hormones adrenaline, cortisol, cytokines, thyroid hormone, glucagon and others are elevated post marathon and continue to break down glycogen, fat and protein to fuel restoration, Cortisol, norepinephrine and glucagon lower insulin levels impairing glucose and fat entry into cells for storage. Cortisol may take a week or more to normalize (2004 Athens Marathon study).

So what should you consume after crossing the marathon finish? Nothing but fluids.

Immediately post run is not an ideal time to stimulate digestion and divert blood flow to the intestines and away from recovery. Although the body uses fat and glucose at the marathon start, fat use increases during the run. High levels of fatty acids at the finish block glycogen synthesis. Muscle building testosterone may be low for a week post marathon and allow amino acids to be used for energy instead of protein synthesis and repair.

Despite what companies selling recovery products claim, consuming calories immediately post-run is not necessary and may be counterproductive. We train athletes to drink and savor their finish. Lying on the grass looking at the sky with legs elevated while icing is ideal. Even those runners who fasted before the marathon to facilitate more fat use as fuel (Dr Jeff article 2), don’t feel like eating till dinner.

First bite - what to eat?

Since altered blood flow and stress during a marathon may damage intestines and microbiome, eating fiber-rich foods will help with repair. Gut microbes metabolize fiber to short chain fatty acids which regulate multiple systems. Fruit and vegetables are a good choice, however, they are not the most fiber-rich foods due to their high water content (up to 99%). Beans, lentils, chickpeas, peas, peanuts and other legumes have twice the fiber of fruit and vegetables. Enjoying lentil soup, a bean burrito or salad with beans and nuts while cherishing your achievement – priceless.

We're excited to re-introduce Dr. Jeff Shapiro to our SFM community. If you're looking to improve your health and performance, you know an overwhelming amount of information and opinion is conflicting, counterproductive or harmful.

We're giving Dr. Jeff a platform to address this.

In his articles, Dr. Jeff will discuss exercise and nutrition physiology (how the body works) allowing you to ignore chatter and reject myths. For example, should you carbohydrate load and/or eat during running? Are pills on SFM weekend harmful? After graduating from Stanford and Yale, Dr. Jeff served as medical director of the San Francisco Marathon for a decade, completed and lectured at 50 marathons and trained athletes to achieve peak organ function for 30 years.

Dr. Jeff appeared on ABC News' 20/20 "Super Humans," consulted for CBS News' 60 Minutes "The Toughest Race" and co-produced “Ultra Running” for The Late Show. At the 2023 San Francisco Marathon, Dr. Jeff received a standing ovation for his presentation on exercise/nutrition physiology and adverse effects of pills.

Since he teaches physiology, Dr Jeff’s presentations will read like science instead of a blog. Train Well with Dr Jeff starting in May 2024.