6 signs dietitians can use to tell if their athletes are poorly fueled

March 25, 2019 Catherine Conelly

A major part of a dietitian’s job and a trainer’s job is to help athletes get in touch with their bodies. It’s not about eating according to the latest fad diet or cutting dairy because one magazine headline says so.

Nutrition isn’t that cookie cutter. Every athlete has different dietary needs depending on their body and their performance goals.

Changes to their training plans and lifestyle habits combined with a lack of understanding of their bodies can further complicate an athlete’s nutrition plan. “The simplest way to define poor fueling is not matching intake with demands,” explains Bob Calvin, director of performance nutrition at EXOS. That includes not only the demands of sport but also of life.

When you’re creating an athlete’s meal plan, make sure to account for the demands of their whole day — not just their training. “It’s all cumulative,” says Calvin. Knowing that their nutritional needs may change as their activity levels change, there are a handful of signs that can clue you in when it’s time to rebalance their diet.

1. Poor mood or mood swings

Athletes typically have zest to train and play. If that’s lacking, it’s a powerful sign that the athlete is poorly fueled, says Calvin. You might also see this manifest as a lack of focus. The Journal of Nutrition, Health, and Aging found that female athletes who weren’t getting enough vitamin B1 were more likely to have mood swings, and male athletes lacking vitamin B1 became more irritable. A lack of vitamin B6 was also associated with poor mood, while proper levels can combat irritability, physical weakness, and low energy.

Teaching athletes to evaluate their bodies every morning can help them recognize low fueling signs like poor recovery time or lack of sleep.

The simplest way to define poor fueling is not matching intake with demands.

If athletes are having difficulty completing their usual number of reps, they may not be getting enough carbohydrates.

2. Inability to complete tasks

If an athlete isn’t able to complete tasks they usually can or they’re struggling to complete their usual reps and sets, these are also signs they’re lacking proper nutrition. “In a lot of segments of society, we tend to shy away from carbohydrates. But if someone is chronically fatigued and doesn’t have energy to last through a session, they may not be eating enough carbohydrates,” says Calvin.

He explains that it could also be a quality issue over a quantity issue. Eating enough food won’t make up for a lack of healthy nutrients, and an athlete who isn’t able to sustain their usual endurance may need to focus more on food quality than quantity.

3. Cognition is lacking

When an athlete doesn’t feel like their head is in the game, nutrition could be the culprit. “Athletes need to fuel their brains to optimize reaction time and make crucial game time decisions,” explains EXOS performance dietitian Denise Alvey. “Just like any other organ in the body, the brain needs to be fueled with quality nutrients to function at its best.”

In fact, the same research published in the Journal of Nutrition, Health, and Aging found that after six days of a vitamin B1 deficiency, young men had lower intelligence. However, symptoms went away once the vitamin was back in their system. If athletes can’t make critical decisions on the field or during practice, re-evaluate their diet.

And don’t forget about hydration. The British Journal of Nutrition found that even mild dehydration affected cognitive performance in male athletes, specifically their vigilance and reaction time. While female athletes didn’t experience the same decrease in cognitive performance during exercise, they did have more issues with post-exercise concentration due to mild dehydration.

4. Poor recovery time

More than two to three days of soreness usually means the body isn’t getting what it needs to properly recover from training. If athletes don’t bounce back as quickly as they’re used to and report being sore for longer, take a hard look at what and when they’re eating.

“Think of the athlete’s body as their house,” Calvin says. “We all have different size homes. One thing we do have in common, despite our size, is we’re always striving to remodel. When we place a stimulus on ourselves, we have to rebuild, refuel, and rehydrate. An 8,000-square-foot mansion needs more materials to rebuild than an 800-square-foot house.”

If athletes can’t make critical decisions on the field or during practice, re-evaluate their diet.

Even mild dehydration can slow reaction time and reduce cognitive performance during and after exercise.

5. Lack of sleep or poor sleep quality

If athletes don’t get the nutrients they need to train and recover, their sleep could suffer. On the flip side, several studies have shown that sleep deprivation can also throw hunger hormones out of whack. It’s a vicious cycle.

Encourage your athletes to evaluate their body every morning. “We’ll routinely ask our athletes to start the day with a self-evaluation,” says Calvin. This could mean they evaluate how well-rested (or not) they feel over breakfast or as they’re getting ready. A simple practice like this can help them stay in touch with their bodies and become more aware when something may be off.

Low levels of vitamin B1 could lead to irritability and low cognition. Foods like beef can restore B1 levels.

6. Losing weight

If an athlete is losing weight and that’s not the goal, it’s another indicator they could be poorly fueled. Think back to what Calvin said about not shunning carbs. This is one scenario where your athlete may need to pack more carbs into their nutrition plan.

However, as you focus on the macronutrients (carbs, proteins, and fats), don’t ignore micronutrients. “They’re not always the sexy nutrients, but we need them to perform at a high level,” says Calvin. To avoid a deficit, make sure athletes are also getting enough nutrients like magnesium, calcium, potassium, and iron. “They help our bodies take those big macronutrients and use them. They’re kind of like the support staff. They may not be on the field on Sunday, but they play an important role,” explains Calvin.

Finally, as a general rule, focus on two words: consistency and balance. If the athlete lacks balance or isn’t consistently fueling for their goals throughout their day, they’re more likely to end up with a fueling problem. In turn, this can decrease performance, and that’s when mistakes happens. That’s why Alvey warns that being poorly fueled can also open the door for injury. Evaluating these factors can not only help you prevent underfueling in your clients but also get them back on track when there’s a problem.

About the Author

Catherine Conelly

Catherine Conelly is a California-based health, fitness, and lifestyle writer.

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