Why You Can’t Out-train an Under-fueling Problem
Training hard is great, but training smart (AKA fueling properly) is even better. Give your body the support it deserves, and you’ll feel the difference in your energy, strength, and recovery.
Many athletes believe they can push harder to compensate for a lack of proper fueling. But here’s the kicker: most people don’t know that under-fueling is their problem.
Sometimes it can feel like, “I’m not doing as well as I think I should. I should probably try harder.” This is creating more problems because the root cause is not that they aren’t well-trained—it’s that they are under-fueled.
If you’ve ever felt this way, I don’t think you’re at fault. There is so much information out there about training, while the nutrition topic is largely ignored unless it’s about dieting or excluding foods. But here’s what I want you to know: Under-fueling is probably why your training and performance suffer. A training program that is not paired with solid nutrition means your adaptations to your training will suffer, your risk of injury is greater, and you may feel like your efforts are in vain.
You wouldn’t expect a car to run without gas, so why expect your body to?
What Happens When You Under-Fuel?
Under-fueling manifests in strange and unusual ways, with both short and long-term effects on the body. For example, you might feel the occasional 3pm energy slump, but this can also occur from inadequate fueling, too. Over time, chronic energy deficiency can leave you feeling zapped with the inability to fully show up in your daily life and training sessions. Additionally, you won’t recover from your hard training sessions, which prevents you from building muscle and strength but also increases the likelihood you’ll lose muscle mass. This could also increase your risk of injury down the road.
It's hard to see and feel the effects over the short-term (i.e., 1-2 weeks), but prolonged under-fueling can contribute to Relative Energy Deficiency in Sport (REDs). REDs is a syndrome that many athletes experience. It occurs when energy consumption doesn’t support energy expenditure. What this means is that when you don’t supply your body with enough energy from food, but are actively training, you risk negative long-term health and performance outcomes.
But many people hear “under-eating” and automatically assume there’s a connection to an eating disorder. While it’s true that these conditions can co-occur, they are not the same. If an individual assumes they don’t have REDs because they don’t have an eating disorder, they are at risk of experiencing similar debilitating effects on performance and, over time, their health. In either circumstance, a medical diagnosis is required.
Training Hard vs. Training Smart
You might be thinking, “Am I under-fueling and over-training?”
There’s a difference between pushing through fatigue and training effectively. If you consistently feel like it’s an effort to train, you don’t listen to your body when it needs rest, and you feel like you have frequent sessions that leave you feeling overly sore, you might be overdoing it.
Training effectively means listening to your body, especially if it needs more rest. My friend and climbing coach, Lauren Abernathy, often reframes the pressure to show up to training as more of an average over time. So, instead of showing up to the gym Monday, Wednesday, and Friday to do specific workouts, she suggests establishing different data-driven training sessions. For example, she once gave me a leg workout and suggested I get it done 4 times that month. This took the pressure off me having to show up every week while adjusting my expectations that success is earned with consistency over time—not force.
In addition to adjusting expectations, it’s important to adjust your nutrition to your training. Fueling well allows for adaptations, strength gains, and endurance. Without adequate nutrition that supports your training goals, you’re calling in debts you can’t afford. Unfortunately, those debts will eventually come due in the form of more fatigue, injuries, and burnout.
Signs You’re Not Eating Enough for Your Training
Under-fueling doesn’t just affect your training. It affects your entire body. However, there are a few indicators that can help clarify if under-fueling is your problem.
Signs You’re Not Eating Enough for Your Training:
Low energy during workouts
Increased cravings, especially for sugar
Trouble sleeping
Decreased performance or strength plateaus
Mood swings and irritability
How to Fuel Smarter (Not Just Train Harder)
Chances are, you probably already know how to train hard. But do you know how to match your fueling to your training needs?
Here are some practical fueling strategies to help support your energy needs and your training goals:
Eat enough: Eating enough protein is indeed important to help build muscle, but don’t forget about your total calories for the day. This includes adequate consumption of carbohydrates and fats, too.
Fuel strategically: Eating carbohydrates before, during, and after training is a classic recommendation in sports nutrition. That’s because carbohydrates are your body’s preferred fuel source, especially during high-intensity or strength-based workouts. You can support your energy levels by eating carbs 30-60 minutes before training, again during sessions longer than 60 minutes, and within 2 hours after your training session concludes to support recovery. As a bonus, add some protein afterward to support muscle growth!
Hydrate: Stay hydrated so your cells can stay healthy and your body can deliver important nutrients (e.g., oxygen) to working muscles! Aim for about half your body weight (in lbs.) in ounces of water per day to maintain hydration. For hot and sweaty training sessions, aim to consume 7-10 oz of fluids every 20 minutes. Consider adding electrolytes to support electrolyte loss in sweat.
Use your intuition: Listening to your hunger cues isn’t always easy when you don’t have an appetite. This is normal for athletes. So, part of building intuition is adjusting your intake based on training load.
Bottom Line: Give Your Body the Support It Deserves
Fueling properly is a non-negotiable for athletes. You need adequate energy intake to support your overall health and training progress. Without this important step, you aren’t setting yourself up for success. There’s no amount of extra training you can do to make up for poor fueling.
