Fasted workouts have become a popular fitness strategy. The idea sounds simple: if you train without eating first, your body has to rely more on its fat stores for energy.
And during the workout, that can indeed mean that a greater proportion of the energy you use comes from fat.
But that doesn’t automatically mean you’ll lose more body fat over the following weeks.
For women in particular, there’s another part of the story that deserves attention: having enough energy available for your body to train, recover and function well.
Both men and women need enough energy to perform and recover.
But a lot of sports research has historically been conducted on men, while the resulting recommendations have often been applied to everyone.
Women also have another factor to consider. The brain monitors whether enough energy is available to support reproductive function. Repeatedly under-fuelling can disrupt the hormonal signals involved in ovulation and oestrogen.
Over time, consistently having too little energy available can affect things such as:
That’s why something that sounds simple, like just train before breakfast, deserves a little more context.
There’s an important distinction between burning fat during a workout and losing body fat over time. Training fasted can increase the proportion of fat your body uses as fuel during that particular session.
But that doesn’t automatically translate into greater fat loss in the weeks that follow. So if fat loss is your goal, training on an empty stomach isn’t automatically the shortcut it’s sometimes made out to be.
Exercise itself is a stressor – a useful one, when your body has what it needs to recover and adapt. Problems can arise when hard training is repeatedly combined with:
Too little food + hard training + high life stress
If too little energy remains after exercise to support the body’s normal functions, this is known as low energy availability. Over time, this can affect recovery, bone health, menstrual function and performance.
An occasional fasted workout is therefore very different from chronically under-fuelling your training. The bigger picture matters.
Your muscles need energy to contract, perform and adapt to training. Carbohydrates are an important source of fuel for moderate-to-high intensity exercise. Protein provides the amino acids your body needs for muscle repair and protein synthesis.
Those things matter for men too. For women, menstrual and reproductive health add another reason to pay attention to consistently eating enough.
Eating before training doesn’t mean sitting down for a full breakfast at 6 AM.
If you train early and don’t feel like eating much, start small.
For example:
Combining some carbohydrates and protein gives you fuel for your workout as well as building blocks for recovery. You can then have your normal breakfast after training and continue with regular, balanced meals throughout the day.
Adequate fuelling continues to matter as women get older. During perimenopause and menopause, hormonal changes can affect sleep and recovery, while declining oestrogen accelerates bone loss.
That makes supporting your body through training, nutrition and recovery particularly important during this transition.
This isn’t about saying you can never train fasted. An occasional session without eating first isn’t the same thing as chronically giving your body too little energy.
The goal is much simpler: make sure your nutrition supports what you’re asking your body to do. Whether you’re training for performance, muscle, health or fat loss, give your body enough energy to train, recover and function well.
We’re training for strength, health and longevity. Let’s eat to support all three.
