Intermittent fasting is believed to be an effective strategy for weight loss along with various other health benefits. From regulating your blood pressure, LDL, HDL cholesterol levels to improving your insulin efficiency and metabolism, intermittent fasting has many health benefits. But how safe is it to combine intermittent fasting and HIIT?
If you are new to intermittent fasting and would like to learn more and need some help getting started, check out our blog, A Complete Guide To Intermittent Fasting + Daily Plan & Schedule.
Working out in the fasting state is a controversial topic. Especially combining intermittent fasting with high-intensity interval training (HIIT). Will it help you lose fat quicker? Is it safe? Let us dig more into this topic to understand how intermittent fasting and HIIT work together.
HIIT or High-Intensity Interval Training
High-intensity interval training (HIIT) is considered a time-efficient exercise strategy that can improve cardiorespiratory as well as metabolic health. This workout duration can last for 10 to 30 minutes. In this, an intense workout is done, followed by a short recovery time.
In spite of being short-duration exercise done twice or thrice weekly, the health benefits of HIIT are comparable or more than moderate-intensity exercise, which is generally practiced for a longer duration. HIIT is one of the quickest ways to burn fat and lose weight.
Another study has revealed that a 10-minute exercise protocol that includes 3 minutes of intense exercise improves skeletal muscle oxygen consumption and cardiometabolic health significantly.
Fasted Exercise Benefits
Our healthcare system suggests fasting as a therapeutic intervention for various chronic, non-infectious diseases. Exercise performed in a fasting state increases lipolysis in adipose tissue. It stimulates peripheral fat oxidation, leading to increased fat burn and weight loss.
In simple words, fasted HIIT allows your insulin levels to drop, allowing utilization of your body fat. Fasting depletes your glycogen stores; hence fat replaces glucose for fuel. Potential benefits of exercising while fasting are;
- Increased fat burn – Research studies have revealed that aerobic exercise performed in the fasted state induces higher fat burn than exercise performed in the fed state.
- Improved endurance – Emerging evidence suggests that exercise performed while fasting can help you achieve peak performance and maintain good health.
- Increased growth hormone – Both fasting and exercise increase the production of growth hormone. A research study indicated that two days of fasting triggered the production of growth hormone by 5 times. Exercise, when combined with increased growth hormone, can help to build muscles.
- Improved insulin sensitivity and glycemic control – Studies indicate long-term exercise training in the fasted state is linked to significant improvements in insulin sensitivity and glycemic control.
To know more about combining intermittent fasting and exercise for better results, read Intermittent Fasting And Working Out Combo For Maximum Results.
Downsides of Fasted Training
Following intermittent fasting and HIIT together may not work for everyone. Here are some drawbacks;
- You may experience fatigue – In the fasted state, you may feel less energetic to perform HIIT. Feelings like headache, dizziness, abnormal heart rate, low blood pressure can make you feel uncomfortable.
- Can be stressful – Some people find it extremely stressful to combine fasting and intense workout, which results in anxiety and poor sleep.
- May lead to muscle loss – Sometimes fasted HIIT cardio may lead to muscle loss.
- You may experience low blood sugar – Which can make you feel lightheaded and lethargic. If you have any underlying metabolic diseases like diabetes, you should consult your doctor and plan your exercise and fasting routine.
Combining HIIT and Intermittent Fasting
So, can we practice intense exercise while following intermittent fasting? Traditionally it is believed that eating carbs is essential for workouts for better endurance. However, HIIT workouts tend to be of a short duration of 10 to 30 minutes; hence stored glycogen is considered enough.
In fact, HIIT workouts during intermittent fasting can help to burn fat quickly. It can be the fastest and healthiest way to lose weight. Combining HIIT with intermittent fasting can take your fitness to the next level, but you should follow a healthy diet and lifestyle to see positive results.
How to Exercise Safely While Intermittent Fasting
Exercising while fasting is not only safe to follow but also has various health benefits. Most of these benefits are due to the depleted muscle and liver glycogen stores that occur during the fast.
Here are some essential things to keep in mind when you combine HIIT with intermittent fasting;
- When you start fasting and exercising, your body may take time to adapt to this new source of fuel. Hence, in the beginning, it is normal to experience a drop in your performance.
- While exercising, whether you are in a fasted state or fed state, keep yourself well hydrated.
- Be mindful when you are strength training, as this needs more carbohydrates. You should consider eating soon after such a workout.
- If you experience frequent episodes of hypoglycemia, ease your workout session. Let your body learn and adapt slowly to this new routine.
Right Time to do HIIT During Intermittent Fasting
When you start exercising after an overnight fast, you are not providing any additional fuel to your body. Hence, your body starts burning stored fat. The HIIT, when done in the morning before your eating window, can be more beneficial.
Also, intense exercise is preferred in the morning hours to support your natural circadian rhythm. As studies indicate, intense exercise, if performed before bedtime, can interfere with your sleep quality. Hence performing your HIIT in the morning hours in your fasting period can help you achieve your weight loss goals faster.
Some beverages can break your fast. To understand what type of beverages can break your fast, read What Breaks A Fast? All You Need To Know On Intermittent Fasting Drinks.
Who Should Avoid HIIT and Intermittent Fasting?
Each individual is different and seeks different results from their exercise and fasting routine. And combining HIIT with intermittent fasting may not work for everyone. If you are unable to follow this routine, it may not be the right choice for you.
The HIIT and intermittent fasting is not recommended for some people, such as;
- People having a nutritional deficiency
- Someone having an underlying medical condition
- People with eating disorders
- Pregnant women
- Someone trying to put on weight
- Also, anyone who finds it stressful to follow should avoid it
Both intermittent fasting and HIIT are great ways to maintain a healthy lifestyle. However, balancing them the right way is essential to reach your fitness goals. The tips mentioned above can help you do it right, but consult your doctor if you experience uncomfortable symptoms. Be gentle with your approach and level up gradually, giving your body enough time to adjust to this new routine.
Remember, we are all unique, and you need to test things out to see what works for you best. Try the fasted workout in the mornings and see if it is the right choice to see for yourself.
Want to take up a 21-day intermittent fasting challenge and achieve your weight loss goals? Sign up for 21-Day Fasting Challenges For Weight Loss. Enroll for an easy and fun way of getting fitter and healthier. In this, you will get daily reminders and motivation to build a habit, stay accountable, and celebrate your progress.