Sprint interval training could burn more fat than HIIT in less time—here's how
According to new research, more than one in five Brits are running one to three times per week, while on TikTok, there are now 292.9 million running posts. There are many good things to come from the trend, but one I’ve noticed is the proof that running needn’t be a one-size-fits-all form of movement.
Between zone 2 training, running backwards, and running purely for enjoyment (often as part of a club), people are adapting how they run to suit them, showing that running isn’t just about going for as long as you can, as fast as you can. Sprint interval training is another form people are trying, and besides the fact that it keeps your runs interesting, experts say it could be beneficial for everything from fat-burning to endurance-building. Here’s what it is, how to do it, and how it could benefit you.
Meet the expert: Lillie Beasdale is Founder and Head Coach at online running coaching collective for women @trainpassa.
What is sprint interval training?
‘Sprint interval training, also known as SIT, is a type of training that involves a maximum work period, followed by a long rest period, repeated for a certain number of repetitions to form a whole workout. Similarly to HIIT (high-intensity interval training), it involves periods of all-out effort, but the rest periods in sprint interval training are typically longer than those during HIIT. For example, a SIT workout might involve four to five sprints of ten seconds, with a three-minute recovery in between each set.’
Does sprint interval training work?
‘That depends on what your goal is. If you’re looking to improve your general fitness, studies show that it can be beneficial for both aerobic and anaerobic fitness. If you’re thinking of incorporating sprint interval training into your routine to burn fat in as short a time as possible, research by RunRepeat showed that SIT resulted in a 39.59% higher reduction in body fat percentage than HIIT. SIT also required 60.84% less time spent exercising than HIIT.
‘It’s worth noting, however, that this research is based on a small sample size, and remember that the exercise form you enjoy and will stay consistent with is more likely to help you gain results. If you don’t enjoy sprint interval training, don’t force it.
‘I would also caveat that sprint interval training comes with a higher injury risk than HIIT workouts as the work effort level is higher, which could rule you out of exercise entirely.’
How do I do sprint interval training?
There are four key things to know when considering a sprint interval training workout:
Perform the exercise bursts at a 10/10 effort level, before taking a longer stretch of recovery before your next set.
Long recovery periods are required due to the high level of lactic acid build-up that occurs from sprint interval training.
Sprint interval training can be done on a treadmill, a track, or a stretch of flat road.
A warm-up and cool-down are essential to bulletproof your body against injury.
Example sprint interval training programmes
Beginner sprint interval training programme
Perform 4 x 10 second sprints at 7/10 effort, with a 3-minute recovery in-between each round. Perform this workout twice per week, leaving at least one rest day between workouts, and complementing with strength training to avoid injury.
Advanced sprint interval training programme
Perform 4 x 25-second sprints at 10/10 effort, with a 2-minute recovery in-between each round. Perform this workout twice per week, leaving at least one rest day between workouts, and complementing with strength training to avoid injury.
Benefits of sprint interval training
1.It’s time-efficient
The aforementioned research by RunRepeat showed that as well as sprint interval training resulting in a 39.59% higher reduction in body fat percentage than HIIT, SIT also required 60.84% less time spent exercising than HIIT.
2. It improves athletic performance
According to a study in the Journal of Strength and Conditioning Research, trained runners were able to improve both endurance and anaerobic (used for short, high-intensity workouts) performance after two weeks of sprint interval training.
3. It builds muscle mass
As per a study in Medicine and Science in Sports and Exercise, sprint interval training could help menopausal women increase lean muscle mass. It’s worth noting that the sprints were performed on a bike, rather than on foot for running sprints, but other studies have also shown that running sprints can improve muscle mass.
4. It increases endurance
For a study published in Plos One, researchers compared the effects of 12 weeks of sprint interval training to traditional moderate-intensity continuous training (also known as MICT, or endurance training) and found that SIT provided the same cardiometabolic benefits despite a five-fold lower exercise volume and time commitment.
5. It could aid weight loss
In a review and meta-analysis published in the British Journal of Sports Medicine comparing HIIT and sprints to continuous moderate-intensity exercise, those who did either HIIT or sprint interval training lost about 29% more weight than those who did continuous moderate-intensity exercise.
Downsides of sprint interval training
High injury risk: ‘Sprint interval training involves working your body at maximal effort, so the demand on your body is extremely high. Whilst you offset this with longer recovery periods within each workout, it does still mean that there is an increased injury risk.’
Fatigue/overexertion: ‘You place huge demands on your body with sprint interval training, so it's essential that you practice good recovery outside of workouts, including complete rest days, good nutrition, and quality sleep. This can be tricky for those with a busy lifestyle, and so this may not be the right type of training for you, as the risk of injury increases further without adequate recovery.’
Tips for sprint interval training
Warm up: ‘It's crucial that you perform a warm-up prior to every sprint interval session. This is to ensure that your muscles are warm and ready, and to reduce risk of injury from the session. Your warm-up should consist of a relaxed pulse-raiser – I usually advise ten minutes of easy conversational running – followed by some dynamic stretching.’
Invest in the right kit: ‘The first and most important thing is a good pair of running shoes; I'd advise going to have your gait (your running pattern) checked at a local retailer to make sure that you are wearing something tailored to your feet and the support they need. A supportive and well-fitting sports bra is also key.’
Progressively overload your training: ‘Don’t increase the amount of sprint interval sessions you do too quickly. Your body needs time to adapt and recover, so if you’re looking to increase the frequency of SIT workouts, I’d recommend only adding in one workout every three weeks, ensuring you leave at least one rest day between each session.’
Focus on form: ‘Executing sprint interval sessions is great – but executing them well is even more important. Run tall with your head, neck and shoulders in line with your hips, and practice drills that train your posture, like high knee stepping.’
Cool down: ‘Like warm ups, it's key to cool down post-session to stave off injury. This should consist of a pulse decreaser (a 10-minute jog, gradually decreasing the speed and/or incline as you go), followed by some static stretching for 10-15 seconds per stretch.’
Who should avoid sprint interval training?
‘Pregnant women should take into account medical advice they have been given by their practitioner in terms of what physical activity they can continue with. In general, it’s not advised that women take up new forms of exercise during pregnancy, so if you haven’t done regular sprint interval training before falling pregnant, now isn’t a good time to start.
‘New runners or people entering a fitness routine for the first time shouldn’t start with sprint interval training. As it’s so physically taxing, I only recommend SIT to those who have a base level of cardio fitness and strength, and therefore will be able to cope with the high demands.’
‘Those with an existing injury or any injury history should seek support from a physiotherapist or medical practitioner before considering sprint interval training.’
Read now: How to practise self-compassion and become more confident
More fitness stories:
What is Pilates? 34 exercises, benefits + 15 best online classes
Weight training for beginners: Benefits, tips, lingo + workouts
20 best HIIT workouts for all levels, from 5 to 45 minutes long
Cut through the noise and get practical, expert advice, home workouts, easy nutrition and more direct to your inbox. Sign up to the WOMEN'S HEALTH NEWSLETTER
You Might Also Like
