Blog Fitness Workouts Hiit Workouts Why Am I Gaining Weight Doing HIIT: Here Is How Too Much Exercise Throws Your System Off-Kilter

Why Am I Gaining Weight Doing HIIT: Here Is How Too Much Exercise Throws Your System Off-Kilter

why am i gaining weight doing hiit

Why Am I Gaining Weight Doing HIIT

HIIT exercises have gained popularity in recent years, and they are famed for their incredible role in helping many lose weight. However, as much as many are shedding off those unwanted pounds, you might realize that in your case, the scale keeps going up. If this is so and you are wondering ‘why am I gaining weight doing HIIT,’ read on to find out why this is happening to you.


Why You May Be Gaining Weight After Working Out?

Many of us start exercising to lose weight, and seeing the number continuously go up on the scale can be frustrating and demoralizing. However, you need to realize that you are not alone. Gaining weight after working out is actually quite common. Here are some reasons behind it (11):

  • More Muscle Equals More Weight

All types of workouts, HIIT included, will make you gain muscle. If you are doing HIIT workouts with weights, then you will gain more muscle than someone who does not incorporate them into their routine. Unlike fat, muscle is not easily seen, especially at the beginning of your weight loss journey.

While muscle and fat weigh the same, the former is more dense, meaning it occupies a much smaller space in the body. For example, placed side by side, 1 kg of fat looks much bigger than a kg of muscle. In light of this, your bathroom scale will register more weight, making you think that you are getting fatter, while, in reality, it recognizes the weight of your muscle.

  • Water Weight

This is caused by multiple factors, including hormones, high sodium and carbohydrate intake, illnesses such as kidney or heart disease, certain medications, and instances of physical inactivity. Changing your diet, drinking more water, and working out can easily eliminate the water weight. As for women, try not to weigh yourself around your period week as you may notice some fluctuation due to hormonal changes (6).

why am i gaining weight doing hiit

  • Post-Workout Inflammation

The fact that you are going hard at the gym or home could be the answer to your question on ‘why am I gaining weight doing HIIT.’ Highly intense exercises cause inflammation to your tissues due to a build-up of white blood cells in the damaged tissues.

  • Post-Workout Supplements

Supplement beverages consumed after a workout contain carbohydrates. While these carbs provide glycogen for the body to use as energy, they also cause water retention, which results in weight gain. The popular supplement, creatine, may cause weight gain through an increase in muscle mass or fluid retention.

  • Your Diet

It is not enough to just do a HIIT workout every day and assume that the pounds will start falling off. Your diet is just as important, if not more essential to your weight and fat loss as working out. Drop all the unhealthy foods and sugars, then replace them with leafy greens, oily fish, fruits, legumes and lentils, and whole grains. Without a proper diet the question ‘why am I gaining weight doing HIIT’ will continue haunting you.

See also
Steady-State Cardio Vs. HIIT: Which One Is Better And Why?

If you wish to cinch your waist, tone up your bat wings, blast away the muffin top – our fitness app was created to cater to all your needs! BetterMe won’t give excess weight a chance!

gaining weight after working out

What Are Some Benefits Of HIIT Training?

  • Weight And Fat Loss

HIIT training is fantastic for anyone who wants to reduce weight and the amount of fat in their body. In 2012, a controlled study found that people who did 20 minutes of HIIT exercises for 12 weeks reduced their weight by 1.5 kgs. They also lost 2 kgs of total fat mass during this time (9). Another thing is that, after a HIIT workout, for your body to go back to its normal resting state, it taps into your stored fat to use it as energy. This continues the process of fat burning and fat loss in your body (1).

  • Improves Cardiovascular Health And Metabolic Capacity

HIIT workouts are known to improve the heart health of people who are in good health. The best part about this form of workouts is that they are also fantastic for people with cardiovascular problems.

Research done using HIIT training in older males showed improved results in their glucose metabolism, cardiovascular fitness, and body composition after just two weeks. These high interval intensity workouts can also improve the cardiorespiratory fitness levels in patients with coronary artery disease, heart failure, hypertension, metabolic syndrome, and obesity (5).

Get your personal plan according to your age and BMI
Select your gender
Male Female
Get your personal plan according to your age and BMI
Select your gender
Male Female

why am i gaining weight doing hiit

  • It Is Not Time-Consuming

Ordinarily, a normal workout session takes 45 minutes to an hour from start to finish. HIIT, on the other hand, takes 20 to 30 minutes, including warmups and cooling down. This makes it the perfect everyday routine for anyone with a busy schedule or someone who just does not want to spend an eternity at the gym.

Exercising, in general, is good for mental health issues ranging from anxiety and stress to more complex and chronic illnesses like depression and schizophrenia. A small study conducted in 2015 on persons with chronic schizophrenia showed that not only does low impact HIIT have fantastic effects on the body weight, body mass index, resting heart rate, and pulse pressure of participants, but it also reduced their levels of anxiety, depression, and social avoidance (3).

  • Boosts Your Metabolism For Hours After The Workout

In 2012, a study showed that a 2-minute sprint can boost your metabolism for up to 24 hours. This is the same boost that you would likely get after doing endurance training for about 30 minutes (10). In 2014, a comparative study also showed that despite the short amount of time spent doing HIIT, the amount of oxygen energy consumed in the following 24 hours was similar to that consumed after performing traditional endurance exercises (4).

  • Muscle Growth

This form of exercise puts a lot of pressure on your muscles, leading them to tear and break. To repair these damaged muscles, your body produces more levels of the human growth hormone, testosterone, and insulin-like growth factor-1 to repair them, which leads to increased muscle volume and definition.

See also
Interval Running For Beginners: The Ultimate Guide

gaining weight after working out

Are HIIT Workouts Good for Weight Loss?

Yes, they are. A great HIIT workout routine will not only burn calories during the workout, but it also keeps your metabolism high enough for you to continue expending energy hours after the routine is done. Below is a sample HIIT routine that you could try for weight loss.

Sample HIIT Cardio Workout at Home: No Equipment

While there is no equipment necessary for this HIIT cardio workout for beginners, you will need a timer, a clear area around you, and a comfortable surface, e.g. a gym or exercise/yoga mat. As always, remember to consult a doctor before attempting any exercises, especially if you have a chronic illness.

Step 1 – Warmup

Each of the following exercises should be done for 30 seconds.

  • Swinging Arms Jumping Jacks

Instead of bringing your arms up and down, swing your arms outwards and sideways as you jump and spread your legs, then bring them together and forward as you bring your legs together.

fitness app

  • Front Kicks With Reaching Arms

Pull your arms up and down as you kick forward with each leg.

  • Standing Alternating Toe Touches

Standing with your feet hip-distance apart, swing your right leg up and touch your left hand to your right toes. Return to the starting position and repeat with your left leg, touching your right hand to your left toes. Remember to keep your chest up.

  • Leg Swings

Lift one straight leg and swing it straightforward and then backward in a controlled pendulum-like fashion. You can hold onto a wall or the back of a chair for balance. Do 30 seconds on the right leg before switching and repeating the movement on the left side.

  • Butt Kicks

Stand with your feet hip-width apart, core engaged, and your hands placed on your hips. Jog in place, kicking your heels high to try to tap your butt.

See also
HIIT Workouts With Weights: This Hardcore Strength-Boosting Routine Is Sure To Leave You Sore

why am i gaining weight doing hiit

Step 2 – Working Sets

Each of these exercises shall be done for 45 seconds.

  • Tap And Clap Jump Squats

  1. Stand with feet wider than hip-width, hands at sides. Squat down, tapping the floor.
  2. Rise from squat, jumping feet together while clapping hands behind back (or just in front of you).
  3. Repeat, immediately jumping back to squat and tapping the floor.

Remember to keep your core engaged and breathe through the workout.

  • Twisting Hops/ Jumping Oblique Twists

  1. Stand with your feet together and bend your elbows, bringing your arms to your waist.
  2. Jump up 3 to 4 inches off the ground and rotate your lower body to the right.
  3. As soon as you land, jump up again and rotate your lower to the left this time.

hiit cardio workout

  • Mountain Climbers

  1. Begin in a traditional plank position with your shoulders directly over your hands and wrists.
  2. Be sure to keep your back flat and your butt down, maintaining a neutral spine. Do not curve your back or sag your hips.
  3. Engage your core and lift your right knee, bringing it toward your elbow (or as far as you can). Return the right knee to the starting position as you simultaneously drive your left knee up toward your left elbow.
  4. Return to the starting position and continue switching legs as you pick up the pace. It should feel like you are running in place in a plank position.

Take a 30-second active break (i.e., move around a little) before repeating all the workouts on step 2 one more time.

BetterMe is your fast-track ticket to a long-lasting weight loss! Tailor your fitness journey and maximize your results with just a couple of swipes!

Step 3 – Working Sets

Just like in step 2, all these workouts should be done on a 45-second timer. Remember to pace yourself.

upper chest exercises

  • Burpees

  1. Start in a standing position with your feet shoulder-width apart.
  2. Squat down with your back straight and your hands on the floor between your feet.
  3. With your weight on your hands, kick your feet back, so you’re on your hands and toes, and in a push-up position.
  4. Do one push-up before jumping your feet back to the starting position.
  5. Push strongly from this position and jump, reaching your arms over your head.

Beginners should omit the push-up (or do a knee push-up) if this variation is too hard.

  • Curtsy Lunges

  1. Start by standing with your feet hip-width apart and place the hands on your hips.
  2. Take a big step back with your right leg, crossing it behind your left. Bend your knees and lower your hips until your left thigh is nearly parallel to the floor.
  3. Keep your torso upright and your hips and shoulders as square as possible to the wall in front of you.
  4. Return to the start position and repeat the movement on the other side.
See also
Beach Body HIIT Workout For Beginners

Read More: Squats vs Lunges: Which One of These Time-Honored Exercises is More Effective?

fitness app

  • Arm Reaching Crunches

Instead of tucking your arms behind your head or crossing them over your chest as you normally would during crunches, push them up and reach to the ceiling as you come up and fold them as you lower yourself to the ground.

Take a 30-second active rest and repeat all exercises listed under step 3.

Step 4

  • Backward Lunge With High Knees

Do 4 reverse/backward lunges (2 on each leg). Once you come back up, jump straight into 8 high knees (4 on each leg).

  • Bicycle Crunches

This is a great variation of the arm reaching crunches above. In this workout, place your arms behind your neck and pedal your legs as if you are riding a bicycle. Bring the right elbow toward the left knee and extend your right leg and vice versa.

why am i gaining weight doing hiit

  • Jump Squats

  1. Start by standing tall with your feet shoulder-width apart.
  2. Keeping your chest up, core engaged, and back flat, push your hips back and lower your body until your thighs are parallel to the floor.
  3. Push yourself back up explosively, jumping straight up.
  4. Land softly, lowering yourself immediately into your next rep.
  • Frog Jumps

This is a simple exercise reminiscent of something many of us did when we were younger. There are no specific instructions for this one. Just repeat what you did in your childhood for 45 seconds.

Take a 30-second break before repeating all the workouts outlined in this step.

Step 5 – Active Cool Down

  • 1 minute of alternating front kicks and squats. Kick once on each side then squat.
  • 1 minute of forward lunges.

why am i gaining weight doing hiit

HIIT Calories Burned Vs. Typical Workouts

How Many Calories Are Burned In 30 Minutes Of HIIT?

A 30-minute HIIT session can burn 25 to 30 percent more calories than a 30-minute steady-state exercise such as cycling, using a treadmill, or weightlifting (2). The best way to know how much calories you are burning during and after a workout is to use a fitness tracker or app.

Why Am I Gaining Weight While Dieting and Exercising?

Here are some possible reasons why you could be gaining weight despite dieting and exercising (7):

High Sodium Intake

Even while making healthier choices, it is good to realize that these foods can have more sodium than you realize. Bread, soup and broth, cottage cheese, and other dairy products are fantastic examples of healthy foods but can carry high amounts of sodium.

See also
HIIT Workouts For Men: Pack A Ton Of Work Into A Short Amount Of Time

You Are Not Eating Enough

Cutting your daily caloric intake is the first step in losing weight. It is advisable to cut just 500 to 1000 calories a day for effective fat and weight loss. Reducing more than this causes your body to believe that you are starving, which makes it hold on to fat to protect you from this assumed starvation.

You Are Over-Exercising

If you are spending up to an hour or more doing HIIT exercise, then you might have the answer to ‘why am I gaining weight doing HIIT.’ Yes, HIIT does mean high intensity, but this does not mean that you should go ham at it believing that more is more. Working out too much leads to overtraining. Over-exercising may stall weight loss and lead to weight gain (8).

The Bottom Line

The question, “Why am I gaining weight doing HIIT?” has multiple answers. However, hormones, water weight, muscle gain, inflammation, and post workouts supplements seem to be the most common reasons for unexplained weight gain.

If you are unsure of what is causing weight gain after a workout, it is best to consult a doctor to try and find the root cause of the issue. Also, be sure to speak to a doctor before attempting any of the above exercises.



This article is intended for general informational purposes only and does not address individual circumstances. It is not a substitute for professional advice or help and should not be relied on to make decisions of any kind. A licensed physician should be consulted for diagnosis and treatment of any medical conditions. Any action you take upon the information presented in this article is strictly at your own risk and responsibility!


  1. 8 Reasons HIIT Workouts are So Effective (2014,
  2. Calories Burned From High-Intensity Interval Training (2020,
  3. Effectiveness of high-intensity interval training on the mental and physical health of people with chronic schizophrenia (2015,
  4. High-intensity interval exercise induces 24-h energy expenditure similar to traditional endurance exercise despite reduced time commitment (2014,
  5. High Intensity Interval Training and Heart Health (2020,
  6. How to lose water weight naturally (2018,
  7. I Am Exercising & Eating Right, Why Am I Gaining Weight? (n.d,
  8. Over-Exercising & Weight Gain (2019,
  9. The Effect of High-Intensity Intermittent Exercise on Body Composition of Overweight Young Males (2012,
  10. Two minutes of sprint-interval exercise elicits 24-hr oxygen consumption similar to that of 30 min of continuous endurance exercise (2012,
  11. Why You May Be Gaining Weight After Working Out (2020,
150 million people
have chosen BetterMe

Short easy workouts

I love the 28 day wall pilates challenge and how each day is short and to the point. Allows me to get a quick workout in the morning before starting my day without going to the gym. Love all of the additional workout options as well. Would recommend

Being able to workout without the…

Jack P.
Being able to workout without the feeling of judgment. But also to feel freedom and flexibility at the same time was amazing.

Exercises are simple but effective

Oudeen H.
All the exercises were manageable and were effective. It's amazing how stretching is key way to exercise.