If you have ever gone out for a ride on the weekend with your local cycling group, you will know that a pre-, mid-, or post-ride cafe stop is an essential part of the experience.
In the world of cycling, performance enhancement is a constant pursuit, and there are many different techniques or tactics that cyclists employ to improve their performance.
One intriguing method that has recently gained attention – and that my clients as a personal trainer are increasingly approaching me with questions about – is fasted workouts.
Fasted training, or “fasted cardio,” involves engaging in exercise on an empty stomach, usually in the morning, following an overnight fast.
In this in-depth analysis, I’ll explore the essential knowledge you need about fasted workouts for cyclists, delving into the science, pros and cons, and who should consider incorporating this approach into their training regimen.
What Is A Fasted Workout?
Fasted cycling involves riding on an empty stomach, meaning that your training occurs after an extended period without food.
Fasted training in the context of cycling is an approach that revolves around the principles of glycogen depletion.
Glycogen, the primary energy source during high-intensity physical activities like cycling, is stored within the muscles and liver.
In fasted cycling, you train without consuming calories or carbohydrates before your ride, prompting your body to rely on its internal energy reserves to power your cycling session.
When you begin your training ride, your body will initially use glycogen as an energy source as it’s readily available. As glycogen levels deplete, the body shifts toward fat oxidation, where stored fat is broken down to fuel the exercise.
Many cyclists opt for fasted cycling early in the morning, heading out the door and jumping on the bike before having breakfast or without any pre-ride snack.
This practice is convenient because you’ve completed the fast phase as you sleep, meaning you could be cycling anywhere from 7 to 16 hours or more since your last meal or snack without having to go hungry during the day.
Fasted cycling isn’t limited to the morning though; some cyclists who follow intermittent fasting diets may choose to go for a ride later in the day, especially on days with time-restricted eating or during alternate-day fasting diets.
Depending on the size and substantiality of your last meal, leave at least 4-6 hours for your body to experience fasted exercise.
To make the most of fasted cycling, consider your body’s energy requirements, proper pre-ride nutrition planning, and adequate hydration to maintain your performance and endurance on the road.
What Are The Benefits of Fasted Training for Cyclists?
Fasted cycling offers several potential benefits for riders. These advantages include:
#1: Fat Utilization
Fasted cycling has been shown to increase the relative percentage of fat oxidation during your ride.
This means that a higher proportion of the calories burned while cycling comes from stored body fat rather than muscle glycogen.
One of the foremost advantages of fasted workouts is the increased reliance on fat as the primary source of energy.
In cycling, your muscles require energy to power your movements. This energy, called ATP (adenosine tri-phosphate), is produced by burning the fuel stored in your body from the nutrition you’ve consumed through your diet.
When your body stores excess carbohydrates, they are converted into glycogen, which is stored in the skeletal muscles and liver. Dietary fat and surplus sugars, when glycogen stores are full, are stored as triglycerides in adipose tissue (body fat).
When you cycle without eating beforehand, your body seeks to conserve its limited glycogen reserves by increasing fat utilization for energy. Some studies suggest that this may result in burning up to 20% more fat during cycling.
It’s essential to note that fasted cycling doesn’t increase overall calorie burning; instead, it shifts the calorie source toward greater reliance on existing body fat rather than carbohydrates.
#2 Weight Management
Fasted training has been associated with improved body composition, making it a valuable strategy that can promote fat loss and aid in weight maintenance.
While cycling on an empty stomach doesn’t directly increase calorie burn, some studies suggest that individuals who exercise this way tend to consume fewer calories throughout the day.
Fasted cycling may influence appetite by suppressing the hunger hormone ghrelin more effectively than cycling after eating.
While it doesn’t burn more calories, it can accelerate weight loss by reducing overall calorie intake. Weight loss depends on the balance between the calories consumed and expended daily, and if fasted cycling curbs your calorie intake, it may help you shed more weight.
#3: Improved Insulin Sensitivity
Certain studies indicate that fasted training may enhance insulin sensitivity, rendering it an attractive option for individuals with insulin resistance or those seeking to prevent diabetes.
Concerns about becoming hypoglycemic often deter cyclists from trying fasted cycling, fearing low blood sugar levels, which can lead to fatigue, dizziness, headaches, irritability, nausea, and reduced performance.
Surprisingly, most studies indicate that fasted cycling doesn’t significantly decrease blood sugar levels, even in athletes with diabetes.
Some research suggests that you may notice an improvement in insulin sensitivity and blood sugar control.
If you have diabetes, consult your healthcare provider before attempting fasted cycling.
#4: Reduced Digestive stress
Cyclists with sensitive stomachs often find that cycling on an empty stomach minimizes issues such as cramping, and bloating.
Studies have shown that nausea is more likely during intense workouts when cycling or exercising with a full stomach.
During exercise, blood is redirected from the digestive tract to meet the increased oxygen demands of working muscles. This effectively halts digestion, causing any contents in your stomach or intestines to sit idle.
This can irritate your gut, leading to nausea, bloating, and gas, potentially causing colonic contractions and the sudden urge to defecate mid-ride.
For those with sensitive stomachs, even small snacks can lead to trouble. In these cases, fasted cycling may offer a better solution.
That said, exercising on an empty stomach can also induce gastrointestinal discomfort, such as acid reflux, nausea, or cramping in some individuals, posing an additional challenge.
#5: Mental Fortitude/Race-Specific Training
Engaging in fasted workouts can cultivate mental fortitude.
The discipline required to persevere through a training session without prior nourishment can fortify a cyclist’s mental resilience.
It can also help imitate a race day scenario or help you prepare for ultra-distance events where your body will likely be depleted.
#6: Convenience
Fasted training offers the convenience of eliminating the need for pre-workout meal planning and preparation.
From a practical standpoint, fasted cycling is often the most convenient or even the only option for early-morning riders who need to get their full workout in quickly.
Instead of waking up earlier to eat and wait for digestion, many cyclists prefer fasted cycling.
What Are The Disadvantages of Fasted Workouts for Cyclists?
Although there are some clear benefits, is it necessary to train fasted? What are the downsides?
Let’s delve into these considerations:
#1: Reduced Performance
For most cyclists, a key concern with fasted cycling is the potential impact on performance.
Research consistently shows that athletic performance tends to suffer when you exercise without consuming adequate fuel beforehand.
The limitation of glycogen stores can make it more challenging to sustain high-intensity efforts.
This affects various aspects, such as strength, speed, and exercise intensity. Performance levels tend to be notably better when you cycle in a fed state, particularly when sufficient carbohydrates are available.
Fasted cycling may also impair your ability to sustain longer rides and increase your perceived exertion, making your bike rides feel more challenging than they actually are.
#2: fat Loss
Many cyclists may be tempted by the idea that fasted cycling leads to greater fat loss and improved body composition.
Although we spoke about it earlier as a positive aspect, research suggests that the outcomes with regards to fat loss are quite similar whether you cycle in a fed or fasted state.
Studies indicate that fat loss and body composition changes do not significantly differ between these two approaches. Thus, it’s essential to manage expectations and understand that the notion of fasted cycling as a superior fat-loss strategy isn’t entirely clear-cut.
#3: Muscle Catabolism
Fasted training may not only promote fat breakdown but also lead to the breakdown of protein (muscle) for energy.
Engaging in fasted cycling can put your body in a state of glycogen depletion, limiting glycogen availability.
While your muscles can adapt to using fats and proteins as alternative energy sources, fasted cycling may lead to a higher contribution of muscle protein for energy.
There’s evidence to suggest that fasted cardio exercise may lead to increased protein utilization as fuel. This, in turn, can compromise gains in muscle strength and size, or even result in muscle loss.
#4: Hormonal Imbalances
Cycling on an empty stomach may lead to elevated cortisol levels, one of the primary stress hormones in the body.
Chronic elevation of cortisol has been associated with increased fat storage, particularly around the abdominal area. Exercise itself is a stressor, and combined with hunger or prolonged fasting, it can significantly elevate cortisol levels.
In addition to the cortisol factor, there’s evidence suggesting that exercising in a fasted state may cause additional hormonal imbalances.
Your hormonal profile can affect your risk of injury, recovery from workouts, and the progress and adaptations your body can make from your training sessions.
Therefore, the potential consequences of disrupting your hormones by cycling on an empty stomach should not be taken lightly, as it can impact your overall training and health.
Should I Do My Cycling Training While Fasted?
The efficacy of fasted training is subject to substantial individual variability. However, because of the significant performance losses, most cyclists will opt for some carbs.
What proves effective for one cyclist may not hold true for another. It is imperative to account for these differences in deciding whether to incorporate fasted workouts.
If you feel better training on an empty stomach, great. If a buddy is strongly recommending you give it a go, but you feel rubbish, then stick to the food.
The only time I will ever personally train fasted is when I accidentally forget my food on a ride, or when I am specifically training my mind and body to be used to stress under food depletion.
The decision to integrate fasted workouts into your training regimen is a personal one, but here are several factors to consider:
- Training Goals: Your training should match your goals. If your main aim is to enhance your cycling performance, especially in high-intensity situations, fasted training might not be the best choice.
- Individual Response: How your body reacts to fasted training is crucial. People vary in how well they adapt to this approach, so it’s important to assess how your energy levels, power output, and overall well-being are affected during fasted workouts.
- Workout Timing: When do you usually cycle? The timing of your training sessions matters. Early morning workouts, when your body naturally goes through a fast, are more suitable for fasted training.
Final Thoughts on Fasted Cycling Training
The decision to incorporate fasted training into a cyclist’s regimen should be contingent on their specific goals and individual tolerance.
While fasted cycling has its merits, it may not be the best approach for most cyclists due to the negative impact on performance and the fact that many of the touted benefits can also be achieved with proper nutrition.
Cycling is a sport that demands energy and endurance, and training in a fasted state can compromise these vital aspects.