I'm trying to strengthen legs and lower back. What are good exercises for these? I don't have any special equipment.

Breakfast: about 0.5- 1 l water 0.5 tablespoon instant coffee 2 packs stevia 0.5-1 cup unsweetened soymilk two slices pineapple 1 slice soy bread 1 Centrum multivitamin 2 tbsp liquid Healthy Greens supplement Lunch 2 soy bread wraps filled with contents of 1 small tin of rinsed tuna slices (total, n...

Usually 30 minutes at max. machine resistance on stationary bike. Work out first thing in the morning before breakfast after choking down lots of water. Was doing 6 days/week but reduced to three. Three other days are for 30 minutes on dumbbell weights and stretches on diff. muscle systems, other da...