One of the great things about HIIT workouts such as Metafit is that it is always possible to adapt each exercise to suit your own individual fitness level. For example, you may be just starting out with exercise in general, or keen to complete some form of resistance exercise a couple of times a week as recommended in the latest NHS Exercise Guidelines. In this case, to begin with you can start with the basic versions of each exercise - for example a plain squat rather than a squat jump. This will enable a low impact form of workout which will still get your heartrate elevated but with a much reduced risk of injury.
Once you are comfortable with the basic versions there is tremendous scope to progress if you want more of a challenge. Incorporating plyometrics is an extremely effective way to burn more calories in the same period of time. It is also essential for anyone who wants to maximise their explosive power to improve performance in running or other sports.
Here's an example plyometric exercise from the Ape Shapes Metafit workout - the Tuck Jump, slowed down.
The knees should be lifted high towards the chest, rather than the heels coming up towards the bottom with the knees staying lower. Notice how increased dorsiflexion at the ankle joint releases all that free elastic energy from the Achilles' tendon, helping me get higher. If you thud heavily on landing, make sure you are bending sufficiently not just at the knee but also at the ankle. If you struggle, then devote time to work on your ankle flexibility and you will notice a big difference.
Alternative 1 - Squat Kicks (low impact)
If you aren't quite ready for the full version of this exercise, then there are a couple of alternatives. One is to "Squat Kicks" in which you complete a squat by kicking in front of you with one leg on the way back up, alternating sides. Keep the toes pointed during the kick and make it explosive! Both feet should be in contact with the floor at all times.
Alternative 2 - Squat Big Knees (higher impact)
The second and more intermediate option which IS plyometric is "Squat Big Knees", in which you complete a squat by lifting one knee up towards your chest on the way back up. The momentum created by this movement will also lift the other foot off the ground at the same time. Both feet should be on the floor before starting the next repetition.
In our Metafit classes, we encourage beginners to start with Squat Kicks, progress to Squat Big Knees and if and when they are ready, to give the full Tuck Jump a try. A good transitional strategy is to complete a few tuck jumps at a time, then complete the rest of the interval with squat big knees. Remember the key is to progress gradually and only when you are ready!