Tone Def

Define your muscles and improve your core strength with our five-move bodyweight circuit.

Stability ball press-up 
Muscles: Chest, arms, core muscles (pectorals, triceps, transversus abodominis, erector spinae)
Why do it? A great exercise to improve your upper-body strength and your core stability.
Technique:
Lie with your chest on a stability ball
Place your hands on the ball next to your chest with your fingers facing down
Keep your feet slightly wider than hip width apart
Straighten your arms and lift your chest and hips off the ball
Slowly lower with control
Safety tip: If the ball wobbles a lot, place it against a wall to give you more stability.

Stability ball cross-overs 
Muscles: Stomach, side muscles (rectus abodominis, transversus abodominis, obliques)
Why do it? This is a great exercise to work your abdominals. 
Technique:
Lie with your lower back supported on a stability ball
Keep your hands next to your ears
Crunch up off the ball, twisting slightly towards the left
Return to the centre position before repeating the crunch towards the right
Alternate between left and right
Safety tip: Keep the ball still throughout the movement.

Stability ball back extension 
Muscles: Back muscles (erector spinae) 
Why do it? This is a great exercise to combat back pain.
Technique:
Lie with your stomach on a stability ball 
Place your feet against a wall or secure object
Cross your arms in front of you and place your hands on your shoulders
Lift your head and shoulders up until you form a straight line between your shoulders hips and knees
Slowly lower with control
Safety tip: Do not hyperextend (over-arch) your lower back. 

Stability ball single-leg split squats 
Muscles: Thighs, bottom, hip flexors, core (quadriceps, hamstrings, glutes, PSOAS muscles, transversus abodominis)
Why do it? This is a great exercise to improve your leg strength and posture.
Technique:
Stand on your right legPlace your left foot on a stability ball behind you
Bend your standing leg to perform a squat
Only bend your leg as much as you feel comfortable with
Push up and straighten your leg back to the standing position
Complete one set on the right before changing over to the left
Safety tip: Focus on one point in front of you to aid your balance. If you find this too hard, hold on to a secure object or wall. 

Reps and sets
Do two to three sets of 15 repetitions.

Rick Pearson is editor of Men’s Running, the UK’s only running magazine written entirely for men.