It’s the most popular trend in fitness – and the most misunderstood. We show you how to get the maximum benefit from HIIT.
Given how popular high-intensity interval training (HIIT) has become in the past few years you might assume that it’s a relatively new concept, but that’s nothing like the truth. As early as 1912 Finnish runner Hannes Kolehmainen used interval-style training to help him prepare for the Olympics. His innovative strategy paid off in the shape of three golds in the 5,000m, 10,000m and cross-country events.
Despite HIIT being over a century old, however, people still sometimes struggle to distinguish what it actually is beyond “hard work, short rests”. And while that description is not wrong, there’s a lot more to HIIT. Read on for a full account of the benefits of HIIT and how to tailor it to your goals.
What Is HIIT?
While “hard work, short rests” is the essence of HIIT, there are five main variables that can change the nature of your HIIT workout massively. The first two are your work and rest durations. Working for 40 seconds and resting for 20 is significantly different to resting for 40 and working for 20, with longer work periods generally being better for improving endurance and shorter ones better for power.
Then there’s the intensity of the work periods. With HIIT you need to be pushing hard to get the most benefit from it, and it’s also important to try and maintain a consistent level of effort across the work periods. That means it’s not just about going all-out, because you won’t be able to sustain it across the workout.
“You need to know your target heart rate or understand the rating of perceived exertion (RPE),” says Philippe Ndongmo, a personal trainer at Dolphin Square Fitness Club in London. Rate the latter out of ten and try to keep the effort constant across every interval.
The fourth variable is the type of rest you do – are you stopping completely or engaging in active recovery, like pedalling slowly on an exercise bike? The latter can help flush out lactic acid ahead of your next work period.
Lastly there’s total volume, as in how many intervals you do. It’s easy to do too much with HIIT, which ends up being of no real benefit because by the end of the workout you’re unable to maintain the intensity. As a rule, start with low volume and go as hard as possible. When it feels easy, add a round or two, but drop the RPE slightly.
That’s just about it. There aren’t any hard and fast rules when it comes to HIIT in terms of the type of exercise you do. It can be done with bodyweight moves, cycling, running or weights, just as long as you’re able to do it at a high intensity. That makes some disciplines more suitable than others. Rattling out efforts on an exercise bike is significantly less dangerous than trying to do heavy barbell squats at a furious pace (please don’t do heavy barbell squats at a furious pace).
You can cycle through a circuit of different exercises for your HIIT session, or stick to one or two for all of your reps. The latter makes it easy to hit your time targets because you don’t have to switch exercise equipment during your rest periods, but doing a circuit containing a variety of moves means you can target more muscle groups during your workout.
The Benefits Of HIIT Workouts
Let’s start with the calories you’ll burn, which are many, not only during the workout but also in the hours afterwards. The latter comes from the excess post-exercise oxygen consumption (EPOC) effect, where your body burns more calories as it returns to its normal resting state after a workout and adapts to the exercise you’ve done. The EPOC effect increases with the intensity of the exercise you do, which is why HIIT is such an effective fat burner.
HIIT also increase your VO2 max, which is the amount of oxygen your body can use and is an indicator of cardio fitness. This is why any running or cycling training plan worth its salt has some form of interval training in it. Increasing your VO2 max is key to working harder for longer, helping you log a 5K personal best, for example.
There are also logistical benefits to HIIT, like the fact your workout takes less time so you can fit it into a lunch break. And while it’s tremendously hard work, the short, sharp challenge of HIIT ensures you’ll never get bored with your training.
When To Avoid High-Intensity Circuit Training
If you’re feeling worn down in the first place, HIIT isn’t the session to go for. “A common mistake with HIIT is the assumption that it trumps steady-state cardio at all times, which isn’t true,” says David Jordan from personal training gym The Fitting Rooms.
“HIIT is highly effective because it requires less time and burns calories during recovery. However, to reap the benefits of HIIT you need to attack it with a lot of energy. On days when you’re feeling less than 100% or, more importantly, you’re sore from your previous workout and are at risk of pulling a muscle, then steady-state cardio is probably more effective – and safer.”
Finally, it’s important to consider how often you can do “real” HIIT. “It’s true that HIIT can trigger protein synthesis but it also causes protein breakdown,” says Jordan. “Doing several HIIT sessions a week would be catabolic so while you’d lose weight overall, some of that loss would be muscle mass.
“If building muscle is a goal, proper weight training still needs to be your primary focus with HIIT as a supplement. A training split of two weights sessions and two HIIT a sessions a week would keep you lean, while making sure you aren’t overtrained.”
Remember: it’s supposed to be short, intense and infrequent, not an everyday effort. Recovery days are vital both for avoiding injury and for ensuring you can actually work at the intensity required for effective HIIT. Simply put, if you’re doing four or five HIIT sessions a week, it probably isn’t real HIIT, and you’re probably going to get injured.
Types Of HIIT Workouts
Beginner: Timmons Method
Developed by a team at Loughborough University, this one’s entry-level. Do 20 seconds of all-out work, followed by two minutes of active recovery (walking/freewheeling will do) or complete rest. Repeat three times, and you’re done.
Also known as “reverse Tabata”, this doubles the rest and reduces the work intervals to shift the focus to anaerobic fitness. Use it if you’re aiming for power production, or if you don’t have the fitness for an all-out Tabata (explained below). Warm up for ten minutes, then do six to eight rounds.
Now things get complicated. In this plan, you’ll do five “blocks” of work, made up of 30 seconds at 30% intensity, 20 seconds at 60% and ten seconds all-out. Result? Lots of volume, at manageable intensity.
The most famous HIIT protocol is ideal for increasing VO2 max – as long as you do it right. Twenty seconds of all-out work, followed by ten seconds of rest, repeated eight times, improved endurance by as much as 30 minutes of steady-state cardio in a Queen’s University study. The key is keeping intensity high – if you can talk during the session, you’re getting it wrong.
Seven HIIT Workouts To Try
Kettlebell HIIT Workout For Fat Loss
A Louisiana University study that compared kettlebell swings, cleans and deadlifts with a more traditional sprint training programme found that maximum heart rate was only slightly higher in the sprints, while calorie expenditure was bigger with the bells.
Here’s one of our favourite circuits. Rest for 30 seconds at the end, then repeat for three to five rounds.
Alternating swing (30sec) Similar to the traditional swing but alternating arms at the top portion of the lift. Clean and jerk (15sec left arm, 15sec right arm) Finish each 15-second work block by pressing the kettlebell over your head. Goblet squat (30sec) Hold the kettlebell close to your chest and keep your back straight.
All-Out Exercise Bike HIIT Workout
There’s a reason lots of studies use exercise bikes: going all-out on the pedals isn’t too technical, injury risk is low and you can ruin yourself. For “supramaximal” efforts, which stimulate every available muscle fibre, the bike is the perfect choice.
When looking to improve the fitness levels of Premier League footballers in pre-season, strength and conditioning coaches at the country’s top clubs have a particular favourite in the Tabata protocol. It’s used up to four times a week and typically performed on an exercise bike. You can reap the same rewards by following the plan: 20 seconds sprint cycle; ten seconds rest or slower cycle; repeat for eight rounds.
Battle Ropes HIIT Workout For An All-Day Burn
In a College of New Jersey study, battle ropes beat 13 other exercises (including burpees) for energy expenditure and produced the highest average heart rate. The protocol: 15 seconds of single-arm waves, 15 seconds of double-arm waves, 60 seconds’ rest, repeated eight times.
Burpee HIIT Workout To Improve Endurance
In the same New Jersey study, burpees beat four other bodyweight moves and every free weights exercise for VO2 response. If you’re short on time and space, use the Wingate protocol: 30 seconds all-out, then four minutes of rest, done four to six times.
Sprint Workout To Increase Power
“Production training” workouts improve your ability to work at maximum effort with short rest. They are ultra-short, super-hard exercise intervals combined with long rests for a workout that’ll improve your power. Use them when you’re chasing a 500m row PB or preparing for a boxing bout.
1 Mountain slider
Work 15sec Rest 1min 30sec Rounds 6
Start in a press-up position with your feet on a pair of small towels or Valslides, then bring one knee and then the other up to your chest as fast as possible. Think of it like a crawling sprint.
Work 15sec Rest 1min 15sec Rounds 6
Holding a light pair of dumbbells at shoulder height or a light barbell on your shoulders, drop into a squat. As you stand up, drive the weight overhead, then lower straight into the next rep.
Endurance HIIT Workout To Improve Your 5K Time
“Maintenance training” workouts use longer work intervals and slightly shorter rests to increase your body’s ability to sustain exercise at high intensity, using both your aerobic and anaerobic systems.
Work 30sec Rest 1min 30sec Rounds 6
Using a moderate-weight kettlebell, swing it back between your legs and then pop your hips forwards to swing it to eye level, letting it drop straight into the next rep.
2 Assault AirBike
Work 15sec Rest 45sec Rounds 10
The Assault AirBike forces you to use your full body for a short-but-nasty experience. Haven’t got one? A regular exercise bike also works.
HIIT Workout To Get Lean In Your Lunch Break
Shortening the rests and keeping the work rate high burns more calories during and after your workout, for maximum fat loss. This session from Ndongmo will get you lean in your lunch break. Do all three exercises to complete one round, and repeat eight times.
Work 20sec Rest 10sec
Explode off the ground and change legs in the air on each rep. Rest for ten seconds, then go straight into exercise 2.
2 High knees
Work 20sec Rest 10sec
Run on the spot, bringing your knees as high as possible. Keep the intensity high throughout, then rest for ten seconds.
Work 20sec Rest 30sec
Drop into a squat and then explode off the floor, landing as softly as possible. Rest for 30 seconds before you start the next round.
Written by Joel Snape for Coach and legally licensed through the Matcha publisher network. Please direct all licensing questions to email@example.com.