Athletes are constantly surrounded by numbers. Goal weights, race weights, body fat percentages, BMI ranges, weigh-ins, and more. But what if there isn’t one perfect number an athlete’s body is supposed to maintain? Set point weight theory offers a very different way of thinking about body weight, one that considers how the body biologically regulates weight and why fighting against that physiology can come at a cost to health and performance.
Rather than focusing on one rigid “goal weight,” I prefer to think about an athlete’s natural weight range, AKA, the range where their body demonstrates that it has enough energy available to support hormonal function, recovery, bone health, training adaptations, psychological well-being, and performance.
Because ultimately, the goal shouldn’t be getting an athlete’s body to conform to a number. The goal should be finding the range where their body can actually thrive.
What Is Set Point Weight Theory?
Set point weight theory proposes that each person has a genetically influenced weight range where the body is biologically comfortable and physiological systems can function optimally.
The key word here being RANGE… not one exact number.
The body uses a complex combination of hormonal regulators, metabolic processes, and behavioral mechanisms to help regulate weight within this range.
That means body weight isn’t simply the result of: Calories in – calories out = body weight
The human body is way more sophisticated than that.
When energy availability changes, the body can adapt by altering metabolism, hormones, appetite, and energy expenditure.
This becomes particularly important when we’re talking about athletes experiencing chronic low energy availability or REDs.
An athlete may be actively fighting against their biology in an attempt to maintain a weight that their body cannot physiologically support, and eventually, the body starts pushing back.
Why I Prefer the Term “Natural Weight Range”
Even the term “set point” can create a problem.
It sounds like we’re looking for another exact number.
“My set point is 145 pounds.”
But that’s not how I want athletes or providers to think about this. In my clinical practice, I use the term natural weight range instead.
A natural weight range recognizes that body weight is dynamic.
Weight can appropriately fluctuate in response to:
- Training load
- Life stage
- Hormonal transitions
- Recovery needs
- Changes in energy demands
Rather than forcing the body toward a predetermined number, we’re looking for the range where that individual’s physiology functions optimally.
That’s an important distinction.
A natural weight range isn’t determined by what an athlete looks like, what another athlete weighs, or what a BMI chart says they “should” weigh.
It’s determined by how their body functions.
The Problem With “Goal Weight”
Sport loves goal weights.
A runner may believe they’ll perform better at their “race weight.”
A coach may recommend losing a certain number of pounds before the season.
An athlete may have a body weight from years ago that they’ve decided is their “ideal.”
The problem is that these numbers are often based on:
- Aesthetics
- Sport culture
- Comparison to teammates or competitors
- Body composition expectations
- Previous performance
- BMI
- An athlete’s lowest historical weight
Very rarely do we stop and ask, was the athlete actually healthy at that weight?
That’s a critical question.
An athlete may say:
“But I ran my fastest times when I weighed X.”
That doesn’t necessarily mean X was their healthiest or most sustainable weight.
Peak performance and peak health don’t always occur at the same time.
In fact, athletes may temporarily perform well while physiologically and psychologically depleted.
That short-term performance improvement can reinforce restrictive behaviors, even while the athlete’s health is beginning to deteriorate.
Your Lowest Weight Is Not Necessarily Your Best Weight
This is where weight history can become misleading.
Athletes often anchor themselves to a previous weight because they associate it with a particular season, race, performance, or version of their body.
But context matters.
What was happening physiologically at that weight?
Was the athlete:
- Menstruating regularly or maintaining healthy reproductive function?
- Sleeping well?
- Recovering from training?
- Maintaining bone health?
- Training consistently?
- Emotionally stable?
- Eating flexibly?
- Free from recurrent injury?
If not, that historical weight isn’t necessarily evidence of where the body “should” be.
It may actually be evidence that the athlete was functioning below their natural weight range.
What Happens When an Athlete Falls Below Their Natural Weight Range?
The body is extremely adaptive.
When energy availability becomes inadequate, it doesn’t simply stop functioning. It starts conserving.
Metabolic rate can decrease. Hormonal systems can be downregulated. Recovery can suffer. Bone health can become compromised.
This is one of the reasons body weight alone is such a poor indicator of whether an athlete is adequately fueled.
An athlete can maintain a relatively stable weight while experiencing significant physiological dysfunction.
That’s why identifying a natural weight range requires us to look beyond the scale.
Signs an Athlete May Be Below Their Healthy Range
There isn’t one symptom or one weight that tells us an athlete has fallen below the range their body can support.
Instead, we look at the bigger physiological picture.
Some signs that deserve attention include:
- Menstrual irregularities or other reproductive hormone changes
- Low libido
- Recurrent injuries
- Bone stress injuries
- Poor recovery
- Persistent fatigue
- Declining training quality
- Difficulty completing workouts
- Sleep disruption
- Mood changes or increased anxiety
- GI symptoms
- Feeling cold frequently
- Rigid eating behaviors
- Social withdrawal around food
- Declining or inconsistent performance
The presence of these symptoms doesn’t tell us exactly what an athlete should weigh.
But they can tell us something important… their current state may not be supporting optimal physiological function.
Recovery Markers Matter More Than Aesthetics
This is where I believe we need to completely reframe the conversation around athlete weight.
Instead of asking:
“Does this athlete look healthy?” or “Has the athlete reached their goal weight?”
We need to ask:
“How is this athlete functioning?”
When determining whether an athlete is approaching their natural weight range, some of the markers I care about most include:
Hormonal Function
Are menstrual cycles regular? What about reproductive hormones? Are they functioning appropriately? Are other endocrine markers beginning to normalize?
Bone Health and Injury Resistance
Is the athlete experiencing recurrent injuries or bone stress injuries? Are they able to tolerate training without constantly breaking down?
Recovery
How long does it take them to recover after training? Are they experiencing prolonged soreness? Can they handle their prescribed training load?
Mood and Psychological Well-Being
Are moods more stable? Is anxiety improving? Is there less rigidity around food and exercise?
Training Quality and Consistency
Can the athlete consistently complete workouts and adapt to training rather than simply survive them?
These markers tell us much more about whether an athlete is adequately supported than appearance ever will.
Your Natural Weight Range May Change
Another reason I prefer the term natural weight range is that bodies aren’t static.
The weight at which an athlete thrives at 20 may not be the same weight at which they thrive at 35 or 45.
Training changes.
Hormones change.
Life changes.
Energy demands change.
Recovery needs change.
Trying to maintain a body weight from an earlier stage of life despite these physiological changes can create an ongoing battle between the athlete and their biology.
A natural weight range allows room for the body to adapt.
That doesn’t mean health is determined by weight.
It means we stop treating weight as though it should remain frozen while everything else about the athlete changes.
Set Point Weight Theory Changes the Goal
One of the most useful things about set point weight theory is that it shifts the question.
Instead of asking:
“What should this athlete weigh?”
We can ask:
“At what range does this athlete demonstrate the physiological, psychological, and performance markers of adequate energy availability?”
That’s a very different conversation. It moves us away from aesthetics and arbitrary numbers and toward individualized function.
Sometimes, that means accepting that an athlete’s healthiest and highest-performing body may be different from the body they (or their sport) thought they were supposed to have.
Stop Chasing a Goal Weight. Start Looking for Physiological Safety.
Athletes come in all shapes and sizes.
We say that frequently in sport, yet athletes continue to receive implicit and explicit messages about what their bodies are supposed to look like.
Set point weight theory gives us an opportunity to challenge that thinking.
An athlete’s healthiest weight shouldn’t be determined by an external ideal, normative range, or the number associated with their fastest race.
Instead, we need to look at the athlete’s unique physiology and ask:
- Are their hormones functioning?
- Are they recovering?
- Are their bones healthy?
- Is their mood stable?
- Can they train consistently?
- Are they adequately fueled?
- Can they participate in their sport without their body continually showing signs of physiological strain?
That’s the information that helps us understand whether an athlete is thriving.
The goal isn’t to force the body toward an arbitrary number.
It’s to support the athlete in finding the natural range where their body has enough energy to maintain health, adapt to training, recover, and perform.
Because health and performance improve when athletes learn to work with their biology rather than constantly fighting against it.
Learn to Assess Weight Through a REDs-Informed Lens
If you’re ready to move beyond arbitrary goal weights and learn how to assess athletes based on physiological function, I invite you to join the REDs Informed Provider Certification Program®.
Inside the program, you’ll learn how to:
- Assess athletes beyond weight and BMI
- Recognize physiological signs of low energy availability
- Evaluate hormonal, metabolic, recovery, and performance markers
- Navigate weight conversations without reinforcing harmful sport ideals
- Identify non-stereotypical presentations of REDs
- Implement evidence-based REDs care in real-world practice
This research-based program is designed to give providers the clinical reasoning and practical tools to assess the whole athlete, not simply determine whether they fall within a predetermined weight range.
Join the REDs Informed Provider Certification Program® and learn how to help athletes work with their physiology, not against it.