Ok, Nat and I did this one this morning. It's tough - I won't sugarcoat it. 

• You need to drag a bench up to the cable machine and make sure there's an ankle strap attachment on the lowest setting
• Pick a LOW weight - trust me, pick a weight that allows you to do 12 repetitions before you need a rest.
• Sit, count slowly to 20, then set up again and work the same leg. Do this 3 times and then change sides.

• Brace your abdominals
• Do NOT arch through the back!

Keep your eyes ahead on the ground
Do NOT drop the head or arch head back

Flex the foot and keep your hips straight
Do NOT lean in to the kneeling leg

Grip the edges of the bench for stability
Heel only needs to rise JUST above hip level

Hold at the top for one count and release SLOWLY!

Do you love it? I swear it works!