Weight Loss and Performance Are Not the Same Goal
Trail Notes | Fuelling & Female Physiology
Weight Loss & Performance
are not the same goal.
It is easy to blur two goals into one: get lighter and get faster.
But weight loss and performance are not the same objective, and treating them as one can quietly hold you back.
Why they pull apart
If you are asking your body to run long, lift heavy, adapt, recover and build resilience, it needs energy. Aggressively chasing weight loss at the same time sends the opposite signal.
Under-fuelling may reduce weight in the short term, but it can also compromise recovery, hormones, bone health, mood, sleep and immune function.
It can compromise the very performance you are training for.
This does not mean an athlete can never pursue a change in body composition. It means that trying to maximise weight loss while also expecting peak training, recovery and race performance creates competing demands. Timing matters. If body-composition change is appropriate, it is better approached gradually, away from the most demanding training and racing periods, and with support from a qualified sports dietitian.
Strong goals need strong support
Sometimes body composition shifts as a by-product of consistent training and better health foundations. That is different from forcing a deficit while loading up your training. One supports adaptation. The other competes with it.
This matters even more through perimenopause and menopause, when protecting muscle and bone becomes increasingly important. Strength training, adequate protein and enough overall energy provide the foundation. Aggressive restriction can work against it.
When the pursuit starts costing you
Under-fuelling does not always look dramatic. It can build quietly while you continue completing the program. You may still be training, but not recovering or adapting as well as you should.
Signs worth paying attention to include:
- Training that feels harder than it should
- Persistent fatigue or heavy legs
- Poor sleep or waking hungry
- Feeling cold frequently
- Irritability, low mood or difficulty concentrating
- Repeated illness, niggles or injuries
- Slower recovery or declining performance
- Changes to your menstrual cycle
None of these signs proves that you are under-fuelling, and each can have other causes. But a pattern is worth taking seriously. Low energy availability can affect health, training response and performance, even when weight loss was not intentional.
Pick the goal, then fuel it
If your season is about a race, increasing distance or getting stronger, let that be the primary goal and fuel the work required to reach it.
That means eating before demanding sessions, practising fuelling during long runs and recovering with carbohydrate, protein and enough overall energy. It also means avoiding the temptation to earn food through training or compensate for what you have eaten by adding more exercise.
If changing your body composition remains important to you, seek qualified support and choose a period when training demand is lower. You do not need to pursue every goal at the same time.
Her Trails coaching cue
Choose the primary goal for this season.
Decide what you are asking your body to do, then give it the support required to do it well.
stronger, not smaller
Written by the Her Trails coaching team
Trail Notes are evidence-informed coaching journals written for women who train, race and run on trails.
Go deeper inside Her Trails
See Know Your Macros: Fuel and Recover and our session with Dr Kirstey Holland in Base Camp. Our programs are built to help you become stronger, more capable and better supported.
Evidence informing this Trail Note
International Olympic Committee consensus statement on Relative Energy Deficiency in Sport, 2023. International Society of Sports Nutrition position stand on the nutritional concerns of the female athlete, 2023. Mathisen et al., best-practice recommendations for body-composition considerations in sport, 2023.
General education only, not medical or individual nutrition advice.
If you are experiencing signs of RED-S, disordered eating or ongoing changes to your health or menstrual cycle, please seek support from a qualified health professional or sports dietitian.
