Just because you have a sore or injured back doesn't mean you have to give up exercising. To stay in shape while your back heals, you can perform activities while you're lying or seated, with your back fully supported. Additionally, many single-leg exercises are typically safe if you're suffering from a bad back. Consult your physician before you try any new exercises, just to be certain.
Be Safe With Squats
If your back is sore you’re certainly not going to put a barbell on your shoulders and perform standard squats. But squat variations can build your quads, glutes and calves without risking your iffy back, including single-leg squats, split squats with one or two legs, and skater squats. Stand with your back to a bench to perform single-leg split squats. Stand about one stride from the bench and position the top of one foot on top of the bench. Bend your hips and front knee to squat straight down. Stop before your rear knee touches the floor, then rise to the starting position. Perform 10 to 15 repetitions and then repeat the exercise with your other leg.
Lunge Ahead, or Back
Lunges are fairly similar to split squats, so it’s no surprise that lunges can strengthen your lower body without straining your back. Perform either forward or reverse lunges to work your legs, glutes and calves. To do a forward lunge, stand straight and then step ahead with one foot. As you move forward, flex your legs and hips so both knees form right angles. Don’t let your front knee pass your toes, and stop before your rear knee reaches the floor. Step back, then repeat the exercise with the opposite leg. Do 10 to 15 reps with each leg.
You can do leg curls, which target your hamstrings, in a variety of ways despite a bad back. This isolation exercise is effective because it doesn't involve any muscles above the waist. Try doing curls face down with your ankles pulling a low cable, or perform the exercise with a standing or seated leg curl machine. To do the seated version, position your back on the machine’s seat, place your ankles on top of the resistance pads and flex your knees to push the pads down as far as possible. Some machines will let you do single-leg curls. Either way, do 10 to 12 reps with each leg.
Loosen Your Hamstrings
Tight hamstrings can cause or exacerbate low back pain, so if you have a bad lower back it’s important to perform exercises to keep your hamstrings loose. Instead of bending forward, as you would with many hamstring stretches, lie on your back and raise one leg so your back is firmly supported by the floor. Grip your leg behind the knee so the leg is fairly straight -- but not locked -- and roughly perpendicular to the floor. Hold the stretch with your leg still for 30 seconds. Perform the stretch twice with each leg, once or twice per day.