Week 42 - Strengthen Your Core
The trunk of your body, also known as your "core", is what gives you most of your strength and equilibrium. Your core is attached to your legs and arms, and includes both your abdominals and your lower-back muscles. As a result, your body relies on your core for every move it makes.
The change
Do a minimum of 10 minutes of core exercises three days a week.
It suggests things like crunches, lateral bridges, bridges, and superman.
Week 41's change