Dr. Stacy Sims answers your questions about all things nutrition.

Dr. Stacy Sims gives her advice on the best recovery foods for after an Ironman, explores some myths about electrolytes, and gives insights into periods and performance. 

When it comes to sports nutrition, you’ll be hard pushed to find an expert with as much academic and in-the-field experience as Dr. Stacy Sims. A leading nutritionist and exercise physiologist who has worked with hundreds of professional athletes and age-groupers, Sims is a go-to resource on hydration, nutrition, and sex differences. In 2017, she was named as one of the top four people changing the landscape in triathlon nutrition—and today we have her fourth column here at Triathlete.com. Each month Dr. Sims will be answering readers’ questions, which you can submit to us at Triathlete.com/askstacy. In this installment, Sims gives her advice on the best foods to eat to recover from an Ironman, she explodes some myths about electrolytes, and gives insights into periods and performance.

1. What are the best recovery foods for post-Ironman?

Recovery from an Ironman event is a multi-faceted task. The race distance itself induces muscle damage and systemic inflammation, and the low-grade inflammation can persist for at least five days post-race. Aside from the muscle damage, there are also fluid and metabolic shifts, gut microbiome disruption, as well as micro- and macro-nutrient depletion. When you first cross the finish line, the goal will be focused on fluid replenishment and to start the reparation process by consuming easy to digest protein, carbohydrates, and a small amount of fat. If you are nauseous and/or have GI distress, try drinking your calories (a small cold, smoothie can go a long way here!). You should aim to have a real meal as soon as possible after the race to start replenishing sodium, potassium, fluids, and supplying additional protein for muscle repair.

In the days following your race, it is not about “all you can eat,” but about supplying nutrient-dense foods to support the rebuilding and reparation process. Reach for fruit, veggies, fermented foods (to help your gut bacteria), and lean sources of protein. For pain and inflammation, try using some natural sources like ginger and turmeric. A study published in the Journal of Pain showed that half a teaspoon of raw ginger root or ground herb lessened next-day muscle soreness by 23 to 25 percent. It’s all due to the pain-relieving chemicals gingerol, shogaol, and zinzerone, which studies suggest might be more effective than popping ibuprofen. And let’s also talk about turmeric: There’s a lot of buzz about this in the world of athletic performance. It might turn everything yellow, but turmeric has also traditionally been used as a powerful anti-inflammatory spice in Chinese and Indian medicine. It’s the curcumin (the yellow and orange components in turmeric) that does the trick, neutralizing free radicals to help decrease painful joint inflammation.

One critical thing to point out about the best recovery foods, however, is that using supplements instead of a diversified and well-balanced diet can do more harm than good. Your cells have undergone serious oxidative damage, but too high concentrations of antioxidants have been shown to interrupt the protective role of the acute, natural, antioxidant responses in DNA stability and repair.

2. Is it true that you can have too many electrolytes? It seems I can never get it right!

During exercise, we hear so much about “needing electrolytes” and “electrolyte replacement,” but it is highly unlikely that the disturbance of electrolyte balance associated with exercise results in a life-threatening issue in otherwise healthy individuals, if electrolytes are replenished readily in foods consumed on a daily basis.

I can hear the cries already: “What about sodium?!” Yes, sodium is the only notable exception, primarily due to the role sodium has in acute fluid balance. Hyponatremia has received quite a bit of press in recent history, but in the largest sample of endurance athletes (2,135 race finishers) tested after a race, only six percent of race finishers were hyponatremic, whereas 13 percent of finishers were hypernatremic (elevated blood sodium levels) and the rest had normal blood sodium levels.

Exercise-associated electrolyte disorders are uncommon and generally result from improper hydration advice (sodium imbalance), improper training advice (potassium imbalance), profuse gastrointestinal losses (chloride imbalance), malnutrition, or supplement abuse (magnesium, calcium, and phosphorus imbalance). The best adage to take is to leave the electrolyte tablets on the shelf, and remember to salt your watery fruit and veggies, especially during your taper week.

3. Does your period change your performance?

Let’s start by saying that having your period is an ergogenic aid, that is, it helps enhance performance. Yes, you read that right! What I mean by this is if you understand your cycle, you can maximize training sessions by working with your physiology. During a woman’s menstrual cycle, her hormones fluctuate from low to high, which is termed follicular (low) and luteal (high) hormone phases.

The variation of baseline hormone concentrations can affect a woman’s physical and psychological performance, although it varies from person to person. The follicular phase is marked by the first day of bleeding through ovulation; it’s the time when a woman’s levels of estrogen and progesterone are at their lowest. To put it simply, this is when a woman is “most like a guy” in terms of what is known in sport physiology and nutrition research: Pain tolerance is increased, time to fatigue is increased, intensity and workloads are primed for PRs, and from a metabolic state, a woman’s body can tap into more carbohydrate stores and recover faster (as compared to the high hormone phase).

It is during this low hormone phase that women should aim to hit high-intensity training sessions hard, aim for PRs in power and speed activities, and optimize recovery through nutrition. The luteal phase (approximately the two weeks preceding the start of a woman’s period) is known as the high hormone phase. During this phase, a woman’s physiology is markedly different from a man’s. Progesterone increases her body temperature, increases sodium excretion, increases muscle tissue breakdown, and the combination of elevated estrogen and progesterone decreases the amount of water in the blood, increases the body’s reliance on fat for fuel (but also stimulates fat storage), and increases central nervous system fatigue (she loses her mojo!). One of the best ways to determine how the phases might affect performance is to track your cycle versus your mood and training over the course of three cycles (note: the average woman’s cycle is nearer 32 to 35 days, not the textbook 28!); giving you more objective data to dial in your training and nutrition.

For more information, check out my TED talk here.

Submit your questions for Dr. Stacy Sims at Triathlete.com/askstacy.