Work exercise and leg workouts

I have been doing 2-3 of my work exercises for the last few days.  I started trying to do more leg workouts.  I have an old backpacking pack.  I put some weights in it so it weighs about 35 -40 pounds and I hold one of my 45 pound weights in my hands and do some squats.  I have done one set of that for the last three days.