High intensity training (or HIT) is a huge trend this year - hardly surprising as there's so much evidence it works, as I discovered writing my book, Fast Exercise.
But not only do short, sharp workouts get you fit quick, those explosive bursts of speed have other benefits; for example, fast sprinting engages the glutes with every powerful stride.
Do one of these super-short workouts a day, and you'll have an exceptionally well-toned backside in just six weeks.
Perform 12 of each exercise, take a 15 second break, then go on to the next, for 5 minutes.
Static lunge: Stand with back straight and feet shoulder-width apart. Step forward, bending both knees to 90 degrees and keeping your upper body straight. Push straight back to the starting position and repeat with the other leg.
Deep Sumo Squat: Start with your feet wider than shoulder width apart and arms crossed in front of you for balance. Your toes should point slightly outwards. Squat deep as if sitting on a beanbag.Keep your back straight and head up.
Glute bridge: Lie on your back with knees bent and feet flat on the floor, hip-width apart. Engage the abdominal muscles and squeeze your buttocks to raise your hips off the floor. Press your heels into the ground as you do this. Aim to form a straight line from shoulders to knees. Slowly lower. Repeat.
Stair sprints: Warm up, run fast upstairs then walk down, as many times as you can in 5 minutes. Cool down.
Find a hill. Warm up by walking or jogging for 3 minutes. Perform 4 x 30 second sprints uphill, walking down slowly to recover. Cool down for 2 minutes.