Relative Energy Deficiency in Sport (and Fitness)
It may seem like common sense that athletes demand a high level of energy and nutrients to support their training. Still, it’s often that recreationally active adults assume a healthy and fit lifestyle means a hyper-focus on eating “healthy”. This means different things to different people. When comparing to social-media’s idea of healthy, this may actually be an eating pattern rich in protein and vegetables but low in carbs and calories. It may also mean a diet filled with ultra-processed high protein products without many whole foods. As sports dietitians, we have experience with athletes at every level, from pro to those training at high end fitness clubs. We can tell you without a research study (even though they’re important and we’ll cite them!) that it’s not only athletes that under-fuel their activity. It’s very often everyday exercisers, just like you. That’s why we’re diving into Relative Energy Deficiency in Sport and Fitness. Whether intentional or inadvertent, read on to see how under eating may be impacting your health and performance.
Am I eating enough to fuel my workouts?
In our experiences, we see a lot of inadvertent under-fueling in active gym goers and those who race recreationally. Inadvertent under-fueling may look more like chronic dieting or what other gym goers and influencers consider a “healthy lifestyle”. Unfortunately, most of the accurate messaging around health in the media speaks to those who live mostly sedentary lifestyles. Messaging can be confusing and those who exercise often – along with busy, active lifestyles outside of the gym – wind up eating too little to support what their body and brain need to accomplish.
When you’re in too much of a calorie deficit, your body enters “Low Energy Availability” or LEA. This is when you aren’t eating enough to support both your training and daily activity on top of your basic body functions. Think of all your central nervous system is controlling each day to keep you alive. It doesn’t sound like much, but maintaining your body temperature, supporting normal tissue turnover, breathing, healthy cardiovascular function, hormone production – it all takes a lot of energy. So, if you’re under eating long term, your body may in turn slow down physiological functions. This can lead to well documented potential health consequences of LEA:
Symptoms of under eating for fitness:
- Reduced immune function and getting sick often
- Loss of menstrual function in females, or low androgen hormone levels in males
- Loss of bone mass, increasing risk of fracture
- Impaired heart health and metabolic function
- Poor blood glucose and lipid levels
- Poor mental health and/or cognitive declines
- May look like anxiety, difficulty concentrating, depression
- Slowed energy metabolism and poor tissue turnover
- Can present as hair thinning and loss, brittle nails, skin issues
- GI discomfort: bloating, gas, constipation
Poor fitness progress with low calorie intake:
- Poor responses to and progress with training
- Slowed recovery and/or decreased muscle strength
- Decreased power and/or endurance
- Decreased motivation and enjoyment with exercise
- Poor cognitive performance
- Increased risk of injury
Causes of relative energy deficiency in sport and fitness
Rapid weight loss and low energy availability
There is nothing abnormal about the desire to lose weight. What is abnormal is how quickly people expect to lose weight, how people with a “normal” BMI and metabolically healthy body composition want to get as lean as possible, and the drastic measures people will go to in order to lose weight. Not to mention that what is “drastic” seems to be reasonable based on not only what is seen on social media and the media, but also at times what doctors recommend in their 10 minutes with patients in a typical PCP office.
Even for those who support more “rapid” intentional weight loss, 2 lbs per week is considered the highest healthy loss per week that may be associated with “successful” weight loss. Successful means keeping the weight off for at least one year after reaching a goal weight. For people who are out there looking to “lose the last 5 lbs”, first ask yourself why and at what cost? Does losing 5 more pounds get you to a college weight that no longer fits your stage of life? Is it a pre-pregnancy or pre-menopausal weight that you’re holding onto in your mind? Is it a weight you maintained when you restricted your diet too much in the past? Does reaching that weight mean sacrificing food enjoyment and a social life?
Performance risks of GLP-1 medications
For many that have yo-yo dieted with weight loss, it’s seems logical to go back to all-or-nothing diet patterns, or ride the binge-restrict cycle again. Now though, your metabolism may be trying to protect you by holding onto weight. Even with a binge once a week, a chronic calorie deficit may ensue causing your body to slow down basic functions to protect you. With how rampant and normalized GLP-1 and other weight loss medications are now, the new seemingly logical option is to take one yourself. While some people certainly benefit, for those with intense training programs, who are training for road races, triathlons, or Hyrox, GLP-1 meds come with many risks, including Relative Energy Deficiency in Sport.
Lack of structure and REDS
When LEA is truly inadvertent, it’s often due to lack of a consistent eating schedule with or without knowledge of what an adequate and nutritious eating pattern should look like. I’m looking at you if you’re a young adult in over-achiever mode with intense workouts on your schedule and a high stress job you’re putting too many hours into that leaves you forgetting to snack or even eat lunch somedays. Or if you’re a busy parent prioritizing fitness, while working and shuttling your kids to every activity, leaving you to just eat a yogurt or a protein bar for lunch. The chronic lack of fueling adds up.
Low energy availability with a new fitness routine
Eat a well-balanced diet with 3 balanced meals a day? Whether you signed up for your first half marathon or you started hitting the gym for an hour 5 times per week, sticking with your old eating pattern may work at first. Over time though, not adding in a snack, more carbs at lunch, or fuel during workouts may catch up to you with the signs and symptoms listed above. Training in a similar way to athletes requires a bit of an athlete mentality, especially when you’re new to this level of training. Or if you forget how long it’s been since your high school or college athlete days – your body will be under extra stress and require more energy to re-adapt. Otherwise, your new goals may instead compromise short and long term health, while adding unnecessary stress.
A performance diet to support fitness goals
Everyone is different not only in how they get to a point of under-fueling, but also in what they need to adjust. Both mental health and lifestyle habit wise, your changes will look different. Here’s what to consider:
- If you’re training like an athlete, consider fueling yourself like one
- Improve your relationship with food and body
- Troubleshoot the root of any GI troubles with a real professional
- hint: our wonderful sports RD Kate is also a GI specialist!
- Listen to your body’s unexpected hunger cues during your busy day
- here’s the hunger guide we use early on with 1-1 clients
- Develop and stick to an eating schedule
- Build balanced meals with an easy, no recipe plan
- Determine if you should eat before your workouts
Special nutrition considerations for your training
High intensity and endurance training require more than your average pilates class.