High Intensity Interval Training: safe HIIT workouts

The Definitive Guide to Safe HIIT Workouts That You’ll Ever Need

Get ready for the HIIT fun

When I heard about High-Intensity Interval Training (HIIT) workouts, I was intimidated. But over time, as I started doing HIIT workouts, they became easier and most of all, I enjoyed it.

What is HIIT or high-intensity workouts?

HIIT exercises involve activities of both low and high intensity.

Usually, these two activities are done after each other, so that after a high burst of an intense workout (work period) is followed by a low-intensity period (rest/recovery period). 

When you complete a round of both high and low-intensity sessions, you have completed a work period.

Here’s an example of what a work period might look like:

What are the benefits of HIIT workouts?

Several studies have investigated the health impact of high-intensity interval training. 

In fact, in a recent article, I discussed some of the HIIT benefits, and I’d encourage you to check it out if you want to dive deeper into some of the excellent research.

I’ll try not to reduce those benefits here, but allow me to summarize a few of the benefits before we go on. 

Here are 5 benefits of HIIT:

  1. Improves endurance
  2. Burns calories faster
  3. Increases metabolism
  4. Improves blood pressure
  5. Promotes healthy insulin

How to do HIIT safely?

The benefits are numerous. And it’s not surprising that both professional trainers and newbies tend to use HIIT workouts as the go-to for achieving their health goals.

But here’s the thing:


If you don’t do it safely, HIIT training might do more harm to your body than good. In this article, we go over some of the tips for safe HIIT workouts.

1. Start with a warm-up

warm up

Warm-ups are necessary before any form of exercise because of their immense benefits. And they are important for safe HIIT workouts.

Think of warming up as what an airplane does when it taxies on the runway before getting airborne. It gives you the right speed a trajectory so you avoid any accidents. 

At least five minutes of warm-up prepares the body and muscles for the intense work ahead. 

Skipping the warm-up may cause you to injure a muscle or tendon due to the high intensity of the sessions. 

Your warmup sessions can include a combination of cardiovascular exercises, stretching postures, and strength drills. 

Failure to perform stretches or warm-ups may put some strain on the heart because the heart is not ready to endure the intensity of the training. 

This may lead to serious heart issues. Don’t skip the warm-ups, they are as important as the training itself.

Related: 7 Reasons Why You Should Warm Up Before Workouts

2. Set your performance targets 

It’s tempting to rush into HIIT exercising after watching a YouTube video, thinking you can do it.

The thing your experience level or even body might be different from the other person.

So pick a work period and rest period that you’re comfortable with at the start.

And gradually as you gain more experience, increase those goals to push yourself.

For example, you can start with 60 seconds of workout and 90 seconds rest period. Over time, increase the workout period and decrease the rest period.

Additionally, instead of starting with a high number of sets per workout, you can confine yourself to fewer sets.

This will also help you improve your technique (a safe tip we will discuss in a moment)

This sort of target is realistic, specific, and allows you to develop yourself. Also, I’ve found that doing safe HIIT workouts with that specific target motivates me to give my best.

3. Choose the right footwear

Just as you can’t play a soccer game in flip-flops, the shoes you wear during HIIT exercises matter. 

That’s why The American Orthopaedic Foot & Ankle Society recommends that the type of shoe you choose should depend on the sport you are most active in.

The right footwear helps to provide comfort to your feet and also enables you to do the exercises more efficiently.

Wearing too-tight shoes will impede your ability to work out for long. In tight shoes, your workouts can last for ten minutes when you can go more. 

A comfortable pair of shoes is important because it helps you to move from exercise to exercise during the HIIT training.

It also helps to reduce foot pain and overall enable safe HIIT workouts.

It also helps you to transitions faster and simpler. Heavier shoes will slow you down get you tired earlier than expected.

4. Fuel your body before HIIT

healthy snacks for energy

Nothing can make you give up more quickly on your workouts than a growling stomach. If you want to ensure safe HIIT workouts, you need food.

If you’re going to give your all in a HIIT exercise, fuel your body for this purpose.

HIIT on an empty stomach can make you nauseous and make you feel sick during the entire period.

Remember the goal of HIIT exercises is for you to give your maximum effort in a short period.

Consider eating a moderate to high carbohydrate meal three to four hours before the HIIT workout. Avoid junk food.

Instead, choose energy-boosting foods including whole-grain foods, bananas, sweet potatoes, apples, and oats that are good sources of high carbs. They will help to supercharge your body for the HIIT training.

5. Drink lots of water

The muscles are made up of between 70 to 75 percent of water. The fluid presence ensures that the performance of the muscles is at their peak at all times. 

Drinking water during HIIT exercises is vital.

Staying dehydrated means your muscles are going to work lesser than they are supposed to and your HIIT training going to end up ineffective. 

All safe HIIT workouts require energy and more fluid in your muscles to do what it needs to do. 

Take 8 to ten ounces of water when necessary, every 20 minutes while you’re jumping, planking, crunching—whatever the session be.

6. Stick to your intervals

It’s called interval training for a reason. If you’re doing HIIT you should know your intervals and stick to it to reap all the benefits of the exercise. 

If you are just starting, stick to the thirty-second interval with active resting periods lasting to about 90 seconds. As time goes on, increase your interval times and reduce your resting periods. 


Pay attention to your body to know if it needs more rest time before jumping into another interval. Don’t push the body too hard when you can’t go further anymore.

7. Focus on RPE, not heart rate

It’s very tempting to use how many times your heart is beating (heart rate) to measure how hard you’re exercising.

It’s why people stick to smartwatches and other monitors that tell the maximum heart rate percentage. 

But here’s the thing: if you’re starting, simplicity is your best friend.

Consider Rated Perceived Exertion (RPE) scale instead. The RPE scale is a scale that begins from 0 and ends at 10. It is a simple way to figure out the intensity of your workout.

  • 0: Nothing at all
  • 1: Very Easy
  • 2: Easy
  • 3: Moderate exertion
  • 4: Somewhat difficult
  • 5: Difficult
  • 6: Pretty difficult
  • 7: Very difficult
  • 8: Very very difficult
  • 9: Almost at your maximum
  • 10: Your maximum and hardest.

If you’re healthy, a workout of between a 3 (mild exercise) to a 6 (pretty difficult) is okay.

However, if you’re not, consider starting with a workout between 2 and 3 may be more appropriate. 

8. Choose the right time to exercise

Another factor for safe HIIT workouts is that it requires your body to be at its peak. 

For example for some people that have problems sleeping, a HIIT exercise could either be a blessing or curse. How so?

It could either help them to sleep well or stay awake with so much energy. 

Generally, though, there’s a lot of research that suggests that a moderate amount of exercise increases deep sleep.

When we exercise, we activate the cognitive process of stabilizing our mood and decompressing our minds — both of which are a natural transition to sleep.

However, a good HIIT is more likely to cause your body to release endorphins. This, in turn, will spike activity in your brain and possibly keep you awake.

This is why it’s important to leave enough time for your body to wind down and fall asleep. Avoid doing HIIT too late in the night if you intend to sleep early. 

Consider doing your HIIT exercise at least an hour or two before bedtime. This will allow the endorphins to wind down, allowing your brain to sleep.

Related: Balance Workout Benefits Your Body in These 5 Specific Ways

9. Remember to breathe more

HIIT is intense and it needs energy; energy from the oxygen we breathe in. Thus during your training, make sure you are breathing in and out as much as possible

Inhale through your nose and exhale through your mouth by allowing the air to pass between your teeth. While exhaling, push your belly in. 

This technique will introduce more air into your pelvic floor muscles and diaphragm pushing you to work faster and harder.

10. Rest at your intervals

A friend told me of a HIIT workout based on boxing exercises that go on for 60 minutes without any significant rest periods.

This is not healthy. It is not the way to get the most out of HIIT. Plus, it’s interval training because of the rest time.

When it’s time for you to rest, don’t be shy, take that rest.

11. Use a timer

Speaking of rest, you’re more like to take one if you have a timer. 

During your HIIT training, it is very possible you could be doing your intervals before the set time or probably after the set time. 

Either way, you’re not being disciplined enough to adhere to your interval timing.

Beat this by working with a timer or a stopwatch, so you can monitor and stay in line with your training.

12. Include music to your workouts

Listening to music can have a powerful impact on your workout, and many people who stick up their headphones at the gym know this.

In one study, Dr. Tom Fritz and his colleague Daniel Bowling investigated effort on an exercise machine used with matching music.

The researchers reported that after six minutes of using the machine, the amount of effort a person thinks they are making decreases by half.

But that’s not all, music also serves as natural pain relievers to distract out from the effort itself, and enable you to move faster in HIIT exercises.


One of my favorite clips that combine both music and timer is the famous Tabata songs mix on YouTube. Listen here:


13. Consider adding resistance or weights

HIIT training combined with strengthening exercises is the perfect jumbo mix.

Strengthening exercises such as using weights help to build more muscles, keep them toned, and improve bone strength

With the extra muscles added, you increase the muscle mass which makes it possible to move faster and harder in your HIIT sessions. 

This is even more helpful if you want to lose belly fat.

Your endurance increases as well as your capacity. So do not fear including some weights; they complement each other to give you an effective workout session.

14. User proper form

Workout recovery: How to recover after workouts

Good form refers to your ability to start and complete an exercise in the correct way.

This is an important part of your HIIT training. If you add air squats to your HIIT training, for example, here’s what a proper mechanic will look like:

  • Proper depth
  • Knee alignment
  • Feet flat 

Maintain the right posture all through that one exercise is key to a good workout.

Bad mechanics will lead to bad form. This will result in injury and avoidable back pain. Proper form is a good way to prevent back pain after workouts.

15. Mind your sore muscles

Sore muscles are pains you feel within your body after any workout session.

Sore muscles are experienced the muscles have not been stretched to some extent so when they do, it means you have gone beyond its normal stretch level. 

Don’t use this sore as an excuse to quit the workouts. Instead, perform the sessions at short time intervals with enough resting periods.

16. Know your limits

The whole point of the HIIT training is to do more in less amount of time.

But a few of us can get carried away and decide to either extend the time or do even more within 20 minutes. 

This could lead to injuries, joint pain, poor sleep, increased risk of injury, and extreme tiredness. 

It is therefore advisable to keep your training sessions two to three times a week and more extended recovery time before the next week. 

This allows the body to have adequate rest and be prepared enough for the next training session.

17. Choose comfortable clothing

Several studies including this one have found that the right kind of outfit can impact your workouts.

The makeup of what we wear, how they fit, and the fabric are all critical influences on the amount of sweat absorbed from the skin and transported throughout the clothing. 

And in HIIT exercises, you will be sweating a lot. So choose an outfit you’re comfortable with and one that airs out the heat and absorbs sweat from the skin.

18. Don’t do HIIT every day

You need to rest if you’re looking to maintain safe HIIT workouts for the long term. Don’t let the fun get you carried away. 

Doing HIIT two to four days is good. Once you do it each day, it begins to take a tow on your body.

You need your body to rejuvenate and stay fresh every time you show up for your workouts. So make it a point to have rest days so your body can recover.


19. Add variety

Variety is the spice of life, in this case, variety is the spice of HIIT.

The beauty of your HIIT training depends entirely on you. You get to decide to do either burpees or plans or flutter kicks. 

Sticking to two workouts alone for a while might end up not feeling as intense and fun and it used to be.

Your body could even get used to it and settle for that. Spice it up. Don’t do two workouts in a row. 

Replace your flutter kicks with burpees and your planks with jumping jacks now and then. Mix it up with other CrossFit exercises.

20. Stretch after your workout

Overload any organ of your body could be dangerous. Hamstring pain usually occurs due to a lot of strain and stretching. 

Especially, when you perform sprint, your hamstring muscles contract repeatedly as the leg lengthens with stride.

All this lengthening and loading encourages hamstring injury. 

For example, according to one study, a major risk of hamstring injury or pain is weakness.

When we move, the hamstrings generate enough force to balance out the force produced by the quadriceps. 

The key to avoiding any injuries post-workout is to stretch your muscles. Yoga stretches can be very helpful in this case.

21. Get good sleep after

If you work out all day and don’t get a good night’s sleep, you’re will be cannibalizing the results and gains you could get.

Restful sleep helps the muscle to repair after an intense workout.

With good nutrition and sleep, your body produces its muscle-building hormones. This also helps if you want to wake up early and be more productive.

And it turns out that important and rejuvenating body functions including muscle development and tissue repair happen mostly or only during sleep.

So make sure to get enough sleep. If you have trouble sleeping, consider making these little changes to help you sleep better at night.


HIIT exercises can be a great way to improve your physical condition and stay healthy. Be sure to consider these tips for safe HIIT workouts.