From standing, bring legs up with knees bent one at a time as high as you can. You can put hands out parallel to ground and try to hit hands with knees as you bring them up, alternating legs and doing this as quickly as you can. This exercise is like running on the spot, except that you are keeping back straight and driving knees up high with every rep.

Standing with feet hip width apart, squat down and place hands on ground in front of you, jump legs back into plank position, do a push up, jump legs back in and stand, then roll back so knees are overhead and then forward again and roll right back up to standing. This is one rep. Continue doing as many reps as possible in work interval. 

Start with feet up on ball, hands on floor, and roll ball in towards you bending knees and then back out, at this point do a push up. Continue repeating these movements doing as many reps as you can in the time period. Each push up counts as one rep.

Hold plank position with your feet up on a wall, bring one knee out to side towards same side elbow and bring back in to hold plank against wall, repeat on the other side and continue alternating sides.

Stand a few feet back from a chair with the back towards you, and turn a little to the side so that your right hip is facing the chair. Kick and swing right leg over back of chair and as it comes down on other side pivot body so that left hip is facing chair. This time kick and swing left leg over back of chair, pivoting body back to right side and continue alternating sides for each rep. Each kick over the chair is one rep.

Lie on back, and with arms outstretched to sides and dumbbells in hands raise arms straight up to ceiling with palms facing inward, while lifting legs with Swiss ball held between feet, so soles of feet are facing ceiling. Lower arms w/ db’s and legs with ball simultaneously. If this is too challenging, alternate lifting arms and lowering and then lifting legs and lowering. Practise with lower weight db’s first until you get it.