Exercise is an essential component of a healthy lifestyle. regular physical activity It may help you control your weight, reduce the risk of heart disease and diabetes, and strengthen muscles and bones, per Medline Plus.
However, sometimes, you may want to exercise with caution. Abstaining from food and drink for a specified period – a practice known as fasting – is one such case.
Is it safe to exercise if I’m fasting?
For the most part, it’s OK to rehearse if you’re fasting, “especially if you’re already healthy” William Dixon, MDan emergency medicine physician and clinical assistant professor at Stanford University in California.
Despite this, certain populations should be wary.
People with coronary artery disease (a condition in which the arteries struggle to deliver blood, oxygen, and nutrients to the heart), as well as those on medication for high blood pressure (hypertension) and diabetes are the primary groups that need to be careful.
“A person with coronary artery disease should be careful with exercise in general, especially very strenuous exercise,” says Dr. Dixon, co-founder of Signos, a continuous glucose monitoring app. These people are more prone to cardiac events when their heart rate increases, and they should closely monitor the intensity of their exercise. Fasting is a behavior that can make physical activity more tiring, and therefore puts people with these types of conditions at greater risk of complications than if they were not fasting.
People with type 2 diabetes who take medicines to increase insulin sensitivity or lower blood sugar levels, or people with type 1 diabetes who take insulin, are at risk of having their blood sugar drop too low if they go for long periods without eating.
This is known as hypoglycemia, and its symptoms include shivering, sweating, confusion, rapid heartbeat, nausea, and headache, according to the American Diabetes Association (ADA). Exercising in a fasting state may cause or worsen hypoglycemia in people with diabetes, Dixon says.
Meanwhile, those taking blood pressure medications such as beta-blockers may struggle to raise their heart rate, no matter how vigorously they exercise. “They may be more likely to feel dizzy, especially if they don’t drink enough water,” notes Dixon.
If you have one of these conditions, it is important to talk to your doctor about how to exercise safely if you are fasting (either for dietary or religious reasons), and if it is safe to do so.
In addition, for anyone who is fasting and planning to exercise, it is important to keep in mind that low-intensity, short-duration workouts are better options than long or high-intensity workouts.
You can use the perceived potentiometric (RPE) rating to help you gauge your severity, he says Matthew Accept, CSCSan exercise physiologist at the Hospital for Special Surgery in New York City.
The RPE scale runs from 0 to 10, where 0 corresponds to the amount of effort required to sit in a chair (none), and 10 is the effort it takes to complete an exercise stress test or other challenging (very heavy) activity, for all Cleveland Clinic. Accetta recommends aiming for an effort level of 4 (fairly heavy) or lower while fasting. “Activities like walking, biking, swimming, yoga, and Pilates are all great options.”
It’s OK to exercise in both heat and cold while fasting, “but precautions should be taken to ensure safety,” says Aksita. Make sure you fuel your body properly before you start fasting and limit your intensity (again, don’t exceed 4 on the RPE scale).
You’ll also want to make sure you stay adequately hydrated and get enough sleep, says Dixon. “Both are important for safe workouts and recovery” – especially in hot and cold weather.
Akita says it’s important to eat a balanced diet once the fast is over.
That means enough calories to meet your needs, and a full range of vitamins and minerals, he says. Your daily dietary intake should include complete proteins such as meat, eggs, milk or quinoa, chia seeds and soybeans if you are on a vegetarian diet, along with fruits, vegetables and carbohydrates. Carbohydrates should make up about 40 to 60 percent of your total calories, protein should make up 20 to 30 percent, and healthy fats (such as avocados, fatty fish, and nuts) the remaining 10 to 15 percent.
A registered dietitian can guide you if you’re not sure where to start.
Does the type of fasting affect how safe exercise is?
Fasting varies. Some last only a few hours and some last for weeks.
Spiritual fasting practices such as Ramadan, a holy month in the Islamic religion, specify that eating and drinking only take place at specific times (from dusk to dawn) throughout the month, according to Academy of Nutrition and Dietetics.
Other eating practices, such as intermittent fasting, are undertaken for health reasons or weight loss, in every Johns Hopkins Medicine.
Some of these types of fasting may not mix well with exercise. In particular, fasts of 24 hours or more, fasts in which you restrict calories and nutrients (such as juice), and fasts in which you don’t drink any water, are types of fasting during which exercise is unsafe.
“The body hasn’t had the opportunity to take in new nutrients and replenish its stores,” Aksita explains. At this point, your body is working on the fumes. Not only will the exercise be challenging, but it can also increase your risk of dizziness, fainting, nausea, and headaches.
Axeta says that exercising during intermittent fasting is generally safe. Some people choose to limit eating to a single window of six to eight hours each day, and fast for the remaining 16 hours (plus or minus) per day. Meanwhile, other people prefer to eat normally five days a week and limit themselves to one meal of 500 to 600 calories on the other two days, notes Johns Hopkins.
In general, it’s a good idea to exercise when fasting before a medical procedure, provided you clarify this with the doctor performing the procedure, Aksita says.
Tips to exercise if you’re fasting
Even if you take precautions, exercising while fasting can be risky. If you take medications, have one of the health conditions listed above, or have another health problem that may interfere with your ability to exercise safely (or to fast safely), talk with your healthcare provider before exercising and fasting simultaneously, says Dixon. .
If you want to exercise while fasting, follow these tips for a safer experience, not to mention a more comfortable one.
- Watch your intensity. To conserve energy for the rest of your day, stick to low-intensity exercise while fasting, especially if you exercise at the beginning or midway through your fast, says Accetta. Aim for an effort level of no more than 4 on a scale of 1 to 10, where 1 is resting and 10 is maximum intensity. However, you can probably increase your intensity if the exercise is short. “If you only have 20 minutes to exercise, you can probably perform a higher intensity exercise and get similar benefits to a longer, lower intensity exercise,” says Dixon.
- cut short. Doing a low intensity activity long enough can lead to a higher intensity exercise. This means that walking for three hours while fasting may not be a good idea, even if the walking is of low intensity. If you usually exercise for 30 minutes or an hour at a time, stick to the lower end of that time frame if you exercise while fasting.
- Stay hydrated. Drink plenty of water while fasting and check your urine to gauge how hydrated you are (or not being hydrated): “The darker your urine, the more dehydrated you are,” says Akita. He adds that at least eight glasses of water is recommended.
- Exercise at first. If your schedule allows, try exercising at the beginning of your fast. Since you are eating recently, your body still has plenty of nutrients stored to fuel your workout Mary Wirts, RD, CSSD, a board-certified sports nutritionist in Colorado Springs, Colorado. It may make this exercise easier than if you tried to work out towards the end of your fast when your body is depleted of nutrients.
- Know when your body tells you that you’re overdoing it. Pay attention to your body’s signals, and stop exercising if you feel nauseous, dizzy, or have a headache, Wirtz says. You may also want to replenish with a small snack.