Hello,
I am about 4 weeks away from mastering SLS PE 5 in the foundations 1 course while all of my upper body and core work are just beginning (due to injury, finally all heeled and able to handle the loads of the PE1 progressions for upper body).
Once I master SLS PE5 is it okay to move onto foundations 2 work for legs while still training foundations 1 work for upper body/core?