Intermittent Fasting for Athletes: Is It a Way to Go?

For some individuals, intermittent fasting can be the right method of weight loss. It combines a flexible restriction to eating window ratio and can suit many Americans who aren’t getting the recommended amount of physical activity. But for highly active athletes and runners, a different approach may be needed to maintain their performance and health goals.

This article explores whether intermittent fasting is suitable for athletes and other highly active people.

Can athletes follow a fasting diet?

Intermittent fasting, commonly referred to as IF, is the practice of restricting foods and caloric beverages for periods of time, spanning from hours to days. For the average person, intermittent fasting can be a simple routine. However, when it comes to athletes, IF immediately becomes more complex due to the importance of their unique dietary requirements and exercise routine.

On the one hand, this method of fasting may offer various advantages, including improved physical performance and more desirable body composition. On the other, it can also increase the chances of injuries and an impaired immune system, especially if not done correctly. Whether or not athletes should be incorporating intermittent fasting as part of their diet is an area still being explored by researchers.

Intermittent fasting is a method of eating that focuses on alternating periods of eating and fasting. It can be used as a strategy for weight loss or to give the body a break from digesting food. But, often times more intensive fasting protocols with extended periods without food are discouraged, as such diets can be harmful and lead to deficiencies in the body.

This is especially true for athletes who participate in high-volume workouts that may require proper fuel throughout the day. Despite the potential benefits, there are obvious risks associated with fasting, making it necessary to weigh the pros and cons before beginning any program.

Fasting for athletes: benefits

Among the benefits of fasting for athletes are improved physical performance, improved body composition, and improvement of the immune function.

Improved physical performance

One of the potential benefits of fasting for athletes is improved physical performance. Some studies have indicated that fasting can increase endurance and sprint performance such as:

• Running longer distances
• Faster times
• Less fatigue

This is likely due to the decrease in inflammation, improved muscle protein synthesis, and decreased oxidative stress. It’s important to note, however, that increases in performance only appear to occur from short periods of fasting (typically less than 24 hours), so professional athletes and very active individuals may want to take that into consideration before committing to any type of fasting.

In one study, fifteen male distance runners participated in Ramadan while training. By the end of the month, overall results showed time to exhaustion and maximal running speed of the distance runners improved.

Another study involving twenty male runners who participated in a six-week test saw an overall improvement in their endurance abilities for those who fasted throughout the workout.

There is also evidence coming from the animal studies showing that fasting regimes can improve metabolic health and endurance capacity. However, it is not clear whether these findings would also be replicated in human trials.

Improved body composition

Using IF for athletes and runners may also lead to more desirable body composition. Many athletes aim to achieve a leaner physique, especially those involved in sports involving weight divisions. By reducing caloric intake for an extended period of time, intermittent fasting can help athletes decrease body fat percentages and help to achieve a physique that is essential for their sports.

However, it should be noted that more research is needed on fasting as a weight loss strategy for athletes and its long-term effects on physical and mental health.

Reduce inflammation and improve immune function

Intermittent fasting is also thought to help reduce inflammation in the body. Increased inflammation, especially in athletes, is a significant factor that can negatively affect performance and recovery, potentially leading to overtraining syndrome and a slow recovery process.

Reducing inflammation can help athletes better prepare for workouts and bounce back quicker from training sessions. In this case, the best solution to prevent inflammation is consuming a balanced diet, proper hydration, and adequate recovery time, which all help athletes reach their full potential.

Additionally, some studies have indicated that IF may help athletes reduce inflammation by switching off the inflammatory pathways. There have also been studies on the effects of Ramadan fasting on the immune system, showing how fasting can be linked to the production of new white blood cells that play a key role to fight off infections.

Fasting for athletes: drawbacks

Although, there are some health benefits when it comes to combining fasting and physical performance, the risks are also not to be ignored.

Can interfere with the balance of electrolytes

Despite some potential benefits, fasting for athletes can also have some drawbacks. One potential issue is that fasting can interfere with the balance of electrolytes in the body. Electrolytes, such as sodium and potassium, are essential for muscle contractions during workouts. If athletes don’t replenish their electrolytes while fasting, they can be at risk of:

• Dehydration
• Muscle cramps
• Headaches
• Changes in heart rate during exercise

Furthermore, due to decreased caloric intake while fasting, athletes may experience fatigue. Therefore, it’s essential to keep up with hydration — even during fasting — by drinking water. Athletes with long and vigorous training sessions might want to consider whether fasting is the right strategy for proper hydration and electrolyte balance.

Restriction of food

For athletes who work out several times per day and are burning several thousand calories, food restriction may hinder their performance and health. As mentioned earlier, intermittent fasting for a sedentary individual with a desk job versus an athlete that trains six hours per day, especially endurance workouts, will heavily vary from one’s health conditions to nutritional needs.

Proper nutrition for athletes is vital for maintaining good energy levels throughout workouts and preventing fatigue and decreased muscle mass due to the dramatic change in energy intake vs. output.

Can weaken the immune system

While some studies claim fasting can support immune function, there is evidence demonstrating the opposite. Fasting together with a strenuous exercise routine can be very stressful for our bodies. In turn, this could weaken the immune system and result in infectious disease or increase the chance to get injuries. In addition, restriction of food can potentially cause a deficiency in vital nutrients that the body needs, increasing the likelihood of becoming ill and increasing the time of recovery.

Intermittent fasting for athletes can offer both potential benefits and risks. While the results of scientific studies have been contradictory so far, some athletes have claimed to benefit from such a dietary regimen. However, given the possible risks associated with fasting, it is important for athletes to be informed and to consult closely with a nutritionist before considering a fasting program.