Build a Base for Your Nutrition

Ultimately, the researchers found that preseason energy deficient runners exhibited poorer performance during a collegiate competitive season compared to preseason energy robust runners, suggesting that poor energy status may negate training adaptations and result in minimal performance improvements at the end of the season. They also found VO2 max was lower in the energy deficient female athletes.

In a news release on the study, researchers noted that chronic energy deficiency often happens when an athlete’s energy expenditure exceeds their energy intake in the form of calories. For women, especially, this type of underfueling can not only lead to the poorer performance metrics, but also lead to menstrual irregularities and impaired bone health.

It’s another indication that lighter and leaner doesn’t equal better running performance.

“If you’re not fueling properly, it should show up in your performance,” says Nancy Williams, ScD, FACSM, FNAK, codirector of the Women’s Health and Exercise Laboratory at Penn State, and coauthor of the study.

During the pre- and post-season 5K time trial, there was a two-minute separation between the runners who were metabolically suppressed and the runners who were energy full—a significant difference in time, especially for the distance. The researchers also found that pre-season RMR ratio and a thyroid hormone blood test—an indicator of whole body metabolism—were identified as relevant markers of performance.

What This Means for Regular Runners

While female collegiate distance runners are at a high risk for chronic energy deficiency, Williams said she can see how preseason energy deficiency can also predict poorer performance for everyday runners.

From their findings, Williams hopes coaches and runners become interested in assessing whether athletes are energy deficient and take the necessary steps to address it head on. While acknowledging it’s difficult for athletes and coaches to measure energy status by metabolic compensation without laboratory resources, Williams said she and her team are currently working on a survey aimed to help athletes address whether they are energy deficient.

In the meantime, Williams recommends runners take an intentional approach to their fueling strategy as they prepare for a training build. In other words, just like you build a base for your mileage before a marathon training block, you might want to consider what your regular fuel intake looks like before taking on more mileage and exercise.

Williams suggests working within general sports nutrition guidelines, which offer insight on timing of nutrient intake, the spread of macronutrients, and muscle recovery, among other key elements of fueling.

“What we’re saying is not counter to following good sports nutrition guidelines. We are generally worried about total caloric intake, and there are guidelines for that as well,” Williams told Runner’s World, while explaining that athletes can look at different factors, like their physical activity level, and multiply that by an estimate of metabolic rate to come up with a recommended calorie intake, while also being mindful of the signs for energy deficiency as their training progresses.

Set Yourself Up for Success Throughout the Training Cycle

In terms of planning out your nutrition, start by approaching preseason as the time to set a nutritional foundation for the demands of training, says Namrita Brooke, Ph.D., R.D.N, endurance coach, and sports nutritionist.

Most training plans follow the principles of overload and progression, meaning you’re stressing the body a little bit more each week while allowing time to recover and adapt to the training load and come back stronger for the next phase. “In order to facilitate that adaptation part, your body has to have the energy to actually do that,” Brooke said, while explaining that your body spends extra energy in training and requires even more energy to recover and rebuild. And nutrition is a key part of the adaptation process.

“If we have enough energy, we can rebound from that [training] stress, absorb it, and come back stronger,” she says.

In contrast, underfueling is a stress on the body that can have negative long-term effects on performance and overall health. “Even in your preseason build, if you’re chronically under-fueling over a prolonged period of time, even if you can do the training, you’re still going to have a higher chance of impaired performance later,” Brooke says. “It’s not just about what you’re taking in during your run, it’s your whole diet and the increased calorie needs.”

To ensure you have enough energy to sustain you throughout a training cycle, embrace the mindset of fueling for future performance. Based on the standard diet of three meals a day and a snack or two, Brooke recommends adding more complex carbohydrates, protein, and nutrient-dense foods, like fruits and vegetables, to help the body rebuild from training.

You can do this by slightly increasing the portions of carbohydrates and protein in your meals. For example, if you normally eat yogurt with granola for breakfast, consider adding a banana or a side of toast to the meal. For dinner, if you normally eat chicken with vegetables, add rice or pasta. Other great options for complex carbohydrates include whole grains, vegetables, oats, potatoes, and quinoa.

Once training begins and volume ramps up, Brooke recommends increasing your carbohydrate intake for more energy before, during, and after runs. “As intensity increases, you’re going to be more dependent on carbs,” she said.

Start your day with a prerun carbohydrate-rich meal and snack. You can eat the meal two hours prior and the snack (something small and easy on the stomach, like an energy gel, gummies, or a slice of toast) right before the run. For sessions that are 90 minutes or longer, you’ll want to aim for 60 grams of carbs an hour. For lower intensity or shorter runs, aim for 30 grams of carbs an hour during exercise (if you need it). For these on-the-move sessions, Brooke recommends sport-specific foods that are formulated for digestion during exercise. Within 30 to 60 minutes after the run, take in some recovery nutrition with a meal of carbohydrates and protein while drinking plenty of fluids.

As you progress through the preseason and into the training build, listen to your body’s cues to determine if you’re fueling the right way. Is training going well? Do you feel like you’re recovering? Or are you losing weight, constantly feeling sore, waking up at night hungry, or irritable throughout the day?

“Those are subjective and objective measures that you might not be eating enough calories, in which case I would start with increasing portion sizes,” Brooke said. “Sometimes, people don’t realize that they need to be eating more than they are.”

Taylor Dutch is a writer and editor living in Austin, Texas, and a former NCAA track athlete who specializes in fitness, wellness, and endurance sports coverage. Her work has appeared in Runner’s World, SELF, Bicycling, Outside, and Podium Runner.