High-interval intensity training is for those who want to get fit fast, and it can build muscle and burn fat. However, you need to be able to do it correctly or you will risk injury. There are lots of potential mistakes people can make when undertaking this training, so read on to find out how to avoid them and get the most out of your sessions:Doing HIIT solely for muscle growthHIIT is good for improving your fitness and burning fat, but it’s not good for those who want to gain muscle. To add muscle mass, you should take it slow by lifting big weights and eating larger meals. Although weight-lifting does not burn as much fat as HIIT does, it will release hormones when you put pressure on your muscles, and will make them bigger as a result. HIIT won’t increase as much muscle.Not giving yourself enough timeYou must start HIIT training gradually so you can perform every exercise safely. When you’ve improved your technique, you can speed up. You don’t need to be as careful with exercises like sprinting, but you do need to take care when working out with weights like dumbbells and kettlebells. Taking too long to trainRemember that less is more in HIIT. If you take over 30 minutes to do a high intensity workout, the results won’t come. Try making your workout sessions smaller instead. 10 one-minute sprints are as effective as cycling.Training too muchAfter a HIIT workout that’s been done correctly, your muscles will need to recover. Limit your HIIT sessions to four times a week and give yourself a rest day in between each one, so you can recover and reduce your risk of injury.Using excessively heavy weightsHIIT workouts are loosely based on movements we make every day, so people can take to them quickly and not get injured so easily. It is safer to use lighter weights and do more reps, and avoid heavy barbell snatches. However, if your HIIT sessions consist of resistance training, you will benefit by using heavier weights. You will produce more muscle mass when lifting weights, and when you rest you will then burn more calories.Not warming up correctlyDon’t forget to warm up before a HIIT session, as you’re more likely to get injured if you start training straight away without doing a proper warm-up. Doing HIIT exercises at low intensity will prepare you for a safe, effective workout. For example, if you’re doing a HIIT session consisting of sprint work, try jogging for 10 minutes to warm up.Not fuelling your body properlyIf you’re doing a session which consists of cardio work, eat a light meal at least two hours before it starts. For sessions consisting of strength work, eat something filled with carbohydrates and protein around a hour before your workout. Drink lots of water during exercise. Then within half an hour after the session, drink a protein shake to aid recovery and to restore the nutrients you lost during your workout.