So during my workouts I've been getting some soreness in my lower back. Sometimes when doing front lever work and sometimes from doing leg work on other days. I should add that in addition to Foundation I also do leg press, leg curl, and leg extensions for my leg workouts. After the workout I put some IcyHot or something on and it's ok later that night and the next day. So it's not a lingering pain, just soreness. I stretch before and after the workout. This only started happening in the last few weeks, could it be due to using too much weight on the leg exercises? And really I could use some reccomendations on what to do before/during/after a workout for your lower back mobility and health. Thanks.