This stability ball block builds core stability and strength in the sagittal (flexion/extension), frontal (lateral or side to side) and transverse (rotational Left and Right) planes of movement. Repeat block 2 rounds. The hamstrings curls reinforce this block by developing the posterior chain (backside of body) that targets not only the hamstrings, but also the glutes, erector spinae, triceps and calves.
REFORM Core series
SISS
Tri-Set
x 2