If you have been following our Fit2Win challenge since week one, you will now have a series of exercises that have built up into an effective toning workout.

Today we are publishing four more exercises, all are by fitness expert Mary Morris and taken from Rosemary's latest book, The Secrets of Staying Young.

Do this body-sculpting workout at least three times a week and, for maximum impact, alternate the resistance band exercises with the aerobic exercises.

Start with the warm-up and finish with the stretches that we published last week.

Each workout can be done at two levels – beginner or intermediate. Choose the level that is right for you.

Beginners: Work out at this level if you have not done any formal exercise for a good while or if you are very overweight.

Intermediate: This level is for experienced exercisers who want to be challenged.

Lie on your back with knees bent and place a cushion between your knees (a). With hands behind your head, pull your tummy in tight and lift your head and shoulders off the floor, keeping your chin off your chest and, at the same time, squeeze the cushion to work the inner thighs and the tummy (b). Breathe out as you lift and squeeze and breathe in as you release and lower.

Beginners: Do one to two sets of eight reps.

Intermediate: Do three to four sets of 10 reps.

Come up on to your hands and knees, with knees directly under your hips (or slightly further back, which makes it harder) and wrists in line with your shoulders (a). Lower your upper body towards the floor, bending both elbows and taking your forehead in front of your fingers (b). Push up to straighten your elbows again, but without locking them out fully. Breathe in as you lower, and breathe out as you lift.

Beginners: Do one to two sets of eight reps.

Intermediate: Do three to four sets of 10 reps.

Lie on your back with knees bent and the band placed under your shoulder blades and armpits.

Grip the band between your thumb and forefinger (a).

Pull your tummy in tight and, as you curl your upper body off the floor, keeping your chin off your chest, extend your arms towards your knees (b), then lower again.

Breathe out as you lift and breathe in as you lower.

Beginners: Do one to two sets of eight reps.

Intermediate: Do three to four sets of 10 reps.

Finally, it is time to start work on toning your bottom.

Lie on your back with knees bent and the band placed across your hips. Secure the band on the floor with your hands. Bring your left ankle on top of your right knee (a). (You can keep your feet on the floor if you find this uncomfortable.)

Now, keeping your tummy pulled in tight, lift your hips off the floor without arching your back, and squeeze your buttocks together while keeping the band firmly on the floor (b). Lower again, then lift and lower for a full set of reps before changing legs and repeating.

Beginners: Do one to two sets of 12 reps on each side.

Intermediate: Do three to four sets of 12 reps on each side.