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Undereating may be contributing to your injuries

As an athlete, you want to maintain a low body fat percentage in order to perform well.  There is nothing wrong with this.  It is 100% normal and it just makes sense.  The less fat you have on you, the less weight you have to move through space.  This translates to faster times for most athletes, especially endurance athletes.

A common issue I find with athletes is that in order to maintain their body composition where they want it, they end up significantly undereating.  It is not uncommon for me to find these athletes in a 1000+ calorie deficit from what their body requires.

The body can survive and function for a period of time with a significant deficit, but it cannot thrive.  When a caloric deficit is that significant, your body conserves as much energy as possible.  You may not realize it, but don’t move around as much when you are a significant deficit.  Along with that, you likely don’t have as much energy, strength, or power when training or competing.

But even more important, severe undereating puts you at a greater risk for injury.  When you don’t consume what your body needs to survive and function, it will pull what it needs from wherever it can.  This means it pulls it from your own body.

As you continue in a significant caloric deficit, your body begins to pull energy from itself.  Over time, your own tissues begin to break down.  This can result in a number of injuries.


Tendon breakdown can occur from many reasons; undereating is one of them.  Due to the tension on the tendons during activity, which is good for them in a general sense, if they can’t rebuild due to inadequate nutrition, they can begin to get excessively stressed.

As this continues over time, inflammation occurs.  As the inflammation continues, the tendon begins to breakdown.  Long term consequences can be tendon tears.

Muscle Strains and Tears

Every time you train, you create damage to the muscle in a form of small tears.  The natural repair process the body goes through following this is how we gain strength and muscle size.  It is normal process.

To repair this natural damage, our bodies require adequate caloric intake and adequate protein and amino acid intake.  If you are not consuming enough, your body will not be able to repair the muscle as well, if at all.  Eventually, these small tears can result in muscle strains and possible muscle tears.

Stress Fractures

Stress fractures are common in athletes, especially runners.  The repetitive pounding puts increased stress on the bones.  The question, though, is why do some people get them and other people don’t?  One reason is undereating.  The body will pull nutrients and energy from wherever it can in order to survive when it is significantly underfed.  This results in pulling nutrients from the bones, which weakens the bones.  Over time, the bones develop stress fractures.

Looking back, I can say this is likely why I experienced stress fractures in high school and college.


If you experience frequent injuries that you can’t explain, looking at your food intake may be a good place to start.

Have more questions?  Email me at to get them answered.


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