I tweeted something recently that I received a crazy amount of positive feedback on.
“Low body fat doesn’t mean better athletic performance.”
I don’t know what made me the saddest, the fact that I had to say it, or that several athletes messaged me saying that they needed to hear it.
Some sports and events such as marathons, cycling, dance, gymnastics, rowing or wrestling require a certain aesthetic or a certain weight class to get a leaner body. In the case of running, you can move a lighter body with much more ease. With rowing, erg scores are determined by a power-to-weight ratio, so weight is a heavy concern with crew athletes.
Sadly, when they feel the need to lose weight, most athletes don’t know any other action to take, but to just...eat less.
Or even worse not at all. As in skipping meals.
It’s a dangerously slippery slope that can turn into malnutrition or even disordered eating very quickly and without notice. Usually, this is because daily eyes are on the scale, just waiting for the number to decrease.
The trickier thing still is that, when athletes start slashing calories and experience fast weight loss, they often also get a juicy little boost in athletic performance which sends the message that they are doing the right thing.
I can’t tell you how untrue this is. Here’s why:
1.) Muscle Loss
Putting your body in a calorie deficit via your diet is how weight loss happens. That’s a gimme. However, as an athlete or athletic individual, if you get to this deficit by just randomly slashing calories and skipping while taking no care to how you re-distribute your macros or still get all of your essential nutrients in…
That’s an issue.
Fact of the matter is, when you don’t fuel your body sufficiently, your body will start to break down your muscle for fuel. It’s a survival mechanism.
Muscle breakdown is not only just as unhealthy as it sounds, but obviously, it can hinder performance. Especially when you’re not eating enough to build it back up to where it needs to be.
2.) Faster Fatigue
It goes without saying, food is fuel. What happens when there’s not enough fuel in your car?
It either goes slower or you're pushing that puppy...with much more effort.
Although most people who engage in things like intermittent fasting (myself included on occasion) swear by its ability to give you more energy, for athletes or anyone who works out for longer than an hour, these effects aren’t guaranteed.
There’s also some evidence that not eating enough can disrupt your sleep, causing your body to try to “make up for it” in the waking hours, thus putting you in sort of a waking sleep state that can make physical activity much more difficult.
When you reducing the amount of food you’re giving your body, you also reduce the number of vitamins and minerals you’re giving your body. This puts you at risk for health issues due to nutrient deficiency. Also, there are some nutrients that athletes need more of than others in order to perform optimally. So, if your body is missing these, you’ll be performing far from your peak.
4.) Risk of Bone Fractures
I see this most commonly in female athletes, but it is also entirely possible in male athletes that either have developed disordered eating or have developed a calcium deficiency from lack of food. Studies show that inadequate nutrition can lead to dysfunctions with your hormones, most notably high cortisol and low estrogen.
Why do these shifts matter?
What most people are unaware of is irregularities in hormones, especially estrogen, can have detrimental effects on bone health. Whenever we see an athlete with a hairline fracture (typically in the foot, or elsewhere in the lower body) it’s pretty much a guarantee that they aren’t eating enough.
All of that physical activity, especially for those who play contact sports, also increases the risk the bone breaks.
5.) Reduced Ability to Recover
As I teach in my course The Athlete’s Method, you could argue that recovery is more important than the training itself. That’s because, in order to get bigger, stronger and faster, you have to adapt to that training. This adaptation to improve happens when you fuel your body with enough calories, carbs and protein to replace the energy you lost and supply your body with the amino acids it needs to build more muscle. If you are undereating, you’re likely not getting nearly enough of these nutrients to optimize your recovery.
Overtraining is a well-known term amongst weight lifters.
Oh, have you never heard of it? You got some reading to do, kid. This is important stuff.
Overtraining is typically characterized as the unpleasant and unhealthy things that happen to your body when you work out too often and for too long. However, what they don’t tell you is that this effect happens faster and it more devastating when you aren’t eating enough.
In fact, if you are cutting enough calories, you can experience the effects of overtraining even on your normal training schedule. So, that’s something to look out for.
7.) Increased Risk of Illness
Once when I was 15, I became deathly ill with what I thought was the flu. And I was super confused because it was the middle of the summer and I nearly never get sick.
The first question my aunt asked me was “have you been eating?”
It didn’t take long for me to realize I had been unintentionally eating only about one meal per day, if that, leading up to the days of my illness.
Some studies show that endurance athletes such as runners and cyclers, in particular, are at an increased risk for upper respiratory infections and therefore may need more nutrients like vitamin C and vitamin A than other athletes. As mentioned, if you aren’t eating enough, you likely aren’t getting all of the nutrients you need to support a healthy immune system.
Don’t be 15 year old me, pls. I was obsessed with Lost and, therefore, not a good role model.
8.) Reduction in Speed and Power
If you compete in any events that require powerlifting or explosive movements such as sprinting, hitting or jumping...you’re going to want to eat enough.
Seriously, I’m not spending a ton of time on this one.
As mentioned, undereating results in muscle breakdown, and this study even mentions that when athletes don’t eat enough (especially enough carbs), it can cause a loss of type II muscle fibers. These are the fibers responsible for generating the explosiveness and speed that most sports require.
So you might wanna hang onto those.
The bottom line? Trust me, I personally know how tempting it is to panic and start skipping meals here and there to prevent weight gain you notice or to even lose a few pounds quickly. Every once in a while couldn’t hurt, right? The problem is that this practice can quickly become a regular habit and, over time, it can have detrimental effects on your body, health and athletic performance.
If you’re an athlete who really wants to lose fat responsibly in a way that won’t compromise these things, you should speak to a sports dietitian for guidance.
If you’re a recreational athlete or weightlifter, check out my program.