One-minute squats. To say the major muscles of the lower body are in decent shape, you should have both power and endurance. The object of the move isn’t to exert burst of strength in multiple short moves but to do a slow burn with one long move.

Stand with your feet shoulder-width apart. Keeping your feet flat on the floor, very slowly bend your knees to lower your body to hips are just below parallel with your knees. Take another 30 seconds to raise yourself back to starting position. A guy in his twenties should have enough strength and staying power to go the full minute. With age, it’s normal to have cheat, knocking 5 to 8 seconds off this time. And don’t try this test if you have a history of serious knee problems, or you might be asking for trouble.
Thirties: 52 to 55 seconds
Forties: 44 to 50 seconds
Fifties: 38 to 45 seconds
Sixties and beyond: 40 seconds or less

What to Do
For lower-body strength, squats also hit multiple muscles: the thighs, hamstrings and buttocks. As an exercise, shorten the down portion to 12 seconds and the up portion to 10 seconds. To prevent injury from repeated motion, halt the squat when your thighs are just above parallel with the floor. Do two sets of as many repetitions as you can. You may want to progress to using weights when this exercise becomes too easy.