Training for a Fall marathon? You need to read this ASAP.

Whether you’re a rookie runner or a seasoned veteran, most athletes have heard the phrase “don’t try anything new on race day.”

It’s an age-old piece of advice. Some athletes follow it religiously, sticking with their tried-and-true peanut butter toast or granola bar. Other athletes choose to live on the wild side, risking it all for the hotel’s pancakes and sausage (it just smells soo good…). We know that switching up our fueling right before a race isn’t ideal. But what about the week leading up to the big competition? How does race-week nutrition impact performance? 

I’ve worked with SO many athletes who “clean up” their diets right before their race, with the hope of snagging a PR. This pre-race ritual looks different for each person. Some people cut out desserts and alcohol. Others boost their intake of fruits, veggies, and beans. Some embark on quick-fix diets, hoping to shed a few pounds to reach their “race weight” (note: this approach is NOT dietitian-approved). So, let’s chat. Do race-week diet changes guarantee success, or do they cause more harm than good? Keep reading to find out WHEN to change your fueling plan, and what you SHOULD be eating leading up to the big race.

What’s wrong with last-minute nutrition changes?

Let’s talk about nutrition in the context of training. Whether you’re gearing up for a 5K or an ultramarathon, most training plans last weeks or months. Let’s think about the WHY behind our training plans. WHY do runners build their mileage for weeks and months before a big race? WHY do we dedicate our time to long-term training cycles instead of quick-fix plans? 

It’s because we understand that it takes time, patience, and a LOT of miles to get results. There’s no crash-course for fitness. You wouldn’t expect to PR from a week of training; so what’s the disconnect when it comes to last-minute nutrition changes? There’s no shortage of diet plans that promise quick results with minimal effort, but when it comes to race-day benefits, these programs just don’t deliver. 

So the last-minute crash diet isn’t going to make me faster- got it. When should I start to implement nutrition changes?

Just like a training plan, nutrition changes should start weeks or months before you toe the line for an important race. If your nutrition choices don’t align with your goals throughout your entire training cycle, you’re selling yourself short. Putting in the work without a fueling plan means that you’re NOT reaching your full potential during workouts. You’re NOT supporting training adaptations through optimal recovery. And, you might be digging yourself into a long-term calorie deficit, which could come back to bite on race day. 

Alright, I’m convinced...the sooner, the better. But what should these nutrition changes look like? 

Calories: First of all, athletes should ensure that their diets contain enough calories to support training needs. Underfueling during your training cycle is a recipe for disaster. Athletes who struggle to meet calorie needs lack the fuel to recover after each session. Over a few weeks or months, this can dig a deep hole, resulting in fatigue and poor performance. It also increases the risk of injuries, which could prevent you from stepping on the starting line. 

Plates: As the intensity and duration of exercise ramps up, athletes can adjust their plates to match training needs. More mileage means more carbs. During the off-season, athletes can maintain energy balance with a lighter plate focused on protein, fruits, and vegetables, with moderate carbs. When workouts become longer and more challenging, plates should shift to provide additional carbs. This might mean an extra slice of toast at breakfast, or a larger portion of pasta at dinner. Continue to include protein to rebuild and repair, plus fruits and veggies to provide healing antioxidants. Fats are essential throughout the training cycle, since they support nutrient absorption and hormone health. Fats are more calorie-dense than the other macronutrients, so when calorie needs increase, larger portions of fats can help athletes avoid underfueling.

Nutrient Timing: During the off-season, some athletes can get away with sporadic fueling. This might mean skipping breakfast, snacking throughout the afternoon, and devouring the entire kitchen at the end of a long day. There are TONS of reasons to be more consistent with nutrient timing year-round (better mood, improved energy levels, reduced cravings...I could go on). However, frequent fueling is ESPECIALLY important when training load increases. Skipping meals and snacks during your training cycle can be a recipe for poor performance and impaired recovery. Eating before and after exercise ensures that you’ll have the energy to execute workouts, and the nutrients to get stronger from these training sessions. Eating throughout the day keeps the recovery cycle rolling. If you’re STARVING mid-morning or RAVENOUS when 3 PM rolls around, chances are, your nutrient timing isn’t ideal. This could indicate that you’re leaving potential training adaptations on the table. During a hard training cycle, eating a balanced meal or snack every 2-4 hours could make a huge difference. 

Alright, got it. So, is there anything I SHOULD change during race week?

Just like winter miles build the base for a strong Spring marathon, solid fueling habits during the training cycle form the foundation for race week. Race-week nutrition should be similar to your marathon taper. Don’t make drastic changes to your food choices. Whole, nutrient-dense foods are amazing for health and performance, but a last-minute change in the fiber consumption can throw your digestive system for a loop. Instead, start incorporating these foods during your nutrition build-up, to avoid unwanted digestive consequences. During race week, most runners can afford a moderate decrease in fiber intake, in favor of simple carbs. Softer, cooked veggies work better than fibrous salads. Plates should include ½ carbs + ¼ protein + ¼ fruit or vegetable. 

Should runners cut out desserts and alcohol right before the race? The answer is different for each person. On one hand, overconsumption of these foods can lead to inflammation and poor recovery. But if these foods are a major part of a runner’s diet, cutting them out entirely can lead to a calorie deficit. You could replace these items with a calorie-equivalent food, but remember that a sudden change in nutrition is NOT the best choice during race week. I hate to be a broken record, but if this change is TRULY important to you, it’s best to start at the BEGINNING of your training cycle. My advice? Moderate portions of desserts and occasional alcohol consumption can be part of a sustainable, successful training plan. 

Now let’s talk about that last-ditch effort to reach your “race weight”.

I hate to break it to you, but dropping weight during the week leading up to a race is NOT ideal. Losing weight requires a calorie deficit, which means your body is taking in LESS fuel than it needs. Showing up to the starting line after a week of underfueling means you’ll be feeling sluggish and slow. While “cleaning up” your diet during race week might lead to weight loss, it’s most likely water weight from cutting carbs. This means your muscle glycogen stores are depleted, leaving less fuel for race-day performance. If you do have a goal weight (more on that here), aim to reach it through a slow, gradual cut instead of a crash diet. 

So, let’s review.

When it comes to nutrition changes that TRULY improve your chance at a PR, starting sooner is better. Fueling is a tool to get the most out of your training plan, so give yourself AT LEAST a month to adapt. A nutrition plan that supports optimal training adaptations should include enough calories to cover exercise, plus a little extra to rebuild and repair. As training becomes more intense, plates should shift to include more of those fueling carbohydrates. Consistent meals and snacks are CRUCIAL to promote optimal performance and recovery, so build a fueling schedule that won’t leave you feeling hangry and depleted.