Fasted workouts, or exercising on an empty stomach, have gained popularity for their potential fat-burning benefits. I’ve noticed a number of fitness enthusiasts promoting such workouts because they believe it’ll help maximise fat loss by forcing the body to tap into stored fat for energy. While this might work for men and younger women, it’s not always beneficial—particularly for women over 40.

Over 40 your hormonal changes, metabolism shifts, and nutritional needs make fasted workouts a less sensible choice. Here’s a few reasons why:

1. Hormonal Imbalances Worsen with Fasted Workouts

As we age our bodies undergo significant hormonal changes, particularly around perimenopause and menopause. This includes fluctuations in oestrogen, progesterone, and testosterone levels. Oestrogen plays a key role in fat metabolism, and when its levels decline, the body becomes more resistant to fat loss, particularly around the abdomen.

Fasting before a workout can further stress the body’s hormonal system, especially cortisol, the stress hormone. Cortisol naturally spikes in the morning to help wake us up, but exercising on an empty stomach can amplify cortisol production. High cortisol levels have been linked to increased belly fat, making fasted workouts counterproductive for fat loss. Additionally, chronically elevated cortisol can disrupt sleep, mood, and metabolism, further compounding the issues caused by menopause.

2. Decreased Energy and Performance

As we age, muscle mass naturally declines—a process known as sarcopenia. Maintaining and building muscle mass becomes a priority, not just for aesthetics but for overall health and metabolic function. Exercising in a fasted state often leads to decreased energy levels, which can result in reduced workout intensity and performance.

For women over 40, strength training and high-intensity interval training (HIIT) are vital for preserving muscle mass and keeping metabolism high as well as bone health. Without sufficient fuel, however, these types of workouts can feel more challenging, leading to poorer results. Inadequate nutrition before a workout might also increase the risk of injury, as muscles need glycogen to function well.

3. Negative Impact on Metabolism

Metabolism slows down as we age, and maintaining a healthy metabolic rate becomes more challenging. Fasted workouts can create a caloric deficit, which might seem appealing for weight loss, but can backfire in women over 40. When the body is deprived of fuel, it may go into “conservation mode” and slow down its metabolic processes to preserve energy, making it harder to burn fat over time.

Additionally, if we don’t eat enough to replenish our energy stores post-workout, we might inadvertently lose muscle mass, which further slows metabolism. This creates a vicious cycle where it becomes more difficult to lose weight or maintain a healthy body composition.

4. Increased Risk of Nutrient Deficiencies

As we age, our nutrient absorption decreases, and we need more of certain vitamins and minerals, such as calcium, vitamin D3, magnesium, and B vitamins. Fasted workouts can increase the risk of nutrient deficiencies if they lead to inadequate post-workout nutrition.

Muscle recovery, bone health, and energy production are all impacted by what we eat, particularly after exercise. If we skip a pre-workout meal and don’t adequately refuel after exercising, we won’t get the nutrients we need to rebuild muscle and maintain bone density. Over time, this can lead to a higher risk of osteoporosis, muscle wasting, and chronic fatigue.

5. Blood Sugar Instability

Maintaining stable blood sugar levels is crucial, particularly as insulin sensitivity tends to decrease with age. Fasted workouts can cause a drop in blood sugar, leading to symptoms like dizziness, weakness, and fatigue. For women over 40, this can be especially problematic, as fluctuations in blood sugar levels can contribute to weight gain, energy crashes, and cravings for unhealthy foods post-workout.

A balanced meal or snack before exercise helps maintain stable blood sugar levels, allowing for a more effective workout without the risk of energy slumps or overeating afterwards.

6. Higher Risk of Overtraining and Burnout

Women over 40 are more susceptible to overtraining and burnout, especially when we combine fasted workouts with other life stresses like work, family, and hormonal changes. Exercise is a form of stress on the body, and while moderate stress can be beneficial, adding the extra strain of fasting can tip the balance towards chronic stress.

Over time, this can lead to fatigue, burnout, and even adrenal fatigue, where the body struggles to produce enough cortisol, leaving us feeling tired, sluggish, and less motivated to exercise.

Better Alternatives to Fasted Workouts

Instead of fasting before workouts, we can benefit from consuming a small, nutrient-dense meal or snack rich in protein, healthy fats, and complex carbohydrates. This will provide the body with the fuel it needs to perform well, build muscle, and burn fat efficiently. Some great pre-workout options include:

• A smoothie with protein powder, almond butter, and berries
• A small bowl of oatmeal with chia seeds and a boiled egg
• Greek yogurt with a handful of nuts and sliced banana

These options help maintain blood sugar levels, optimize energy, and enhance performance during workouts.

The hormonal, metabolic, and nutritional needs of us women over the age of 40 are unique and require a more balanced approach to exercise and nutrition. Instead of training on an empty stomach, fuelling your body before a workout can lead to better performance, improved fat loss, and overall better health.

I always say it but you really do need to listen to your body. Prioritise balanced meals and find an exercise routine that supports your changing needs as you age. You’ll be surprised what a difference you can make when you start working with your body rather than fighting it.