facing forward during your rotation). Return to your start position and then repeat, this time rotating to the left side on the way back up. Repeat, alternating sides on the twist, for 20 reps in total. Opposite arm and leg reach This back and abs strengthener is tougher than it looks! To do: Begin on all fours on the floor, with your hands positioned under your shoulders, knees under hips, back straight and abs tight. Lift your right hand and left knee off the floor and draw your elbow and knee in towards each other (without rounding your back or shifting your weight to the side). Next, extend your right arm up by your ear and your left leg out behind your hip, trying to make a straight line from your right hand through = to your left toe. Hold for one count and then bring your elbow and knee back in towards each other. Do 10 repetitions in a row and then switch sides and repeat. Back Extensions This exercise strengthens all the muscles in the backside of your body (yes, including your booty!). Extend your spine and lift your chest as high as you can off the floor as you lift and reach your arms to the outsides of your thighs, turning your thumbs up towards the ceiling as you lift. Hold for one count and then lower back down to start. Do 15 repetitions in a row. GB Olympian: Beth Tweddle Event: Gymnastics Most enviable body part: