only thing ive ever seen is champion's "speed stepper". its like weighted leg raises
roman chair sit ups
Stretching helps to improve muscle strength. Tight muscles during exercise can actually cause problems. It is best to stretch before and after a workout.
I would recommend the Smith Machine or any machine that focuses on strength resistance. By building muscle mass you can burn off fat quickly. http://www.webmd.com/fitness-exercise/features/best-exercise-equipment-you-are-not-using
all of them
Squat.
Do burpees
Strength is gained by working out. As you strain the muscle, tiny tears are formed and when they repair themselves, they grow bigger and stronger. For size and strength of muscle, such as for football, high weight and low repetition is best. For toning and endurance, such as for runners, low weight and high repetition is best.
Lunges. see: http://en.wikipedia.org/wiki/Lunge_(exercise)
To build upper body strength the best chest exercise is lifting weights.Dumbells are the easiest way.Start on smaller weights and build up to heavy weights.
The ability of muscles to perform over time without significantly losing strength is called muscle endurance. Regular, extended exercise is the best way to build endurance.
The only way to build muscle is with exercise. That being the case, since exercise requires calories, building muscle will also burn off fat.
The best strength excercises are compound movements (more than 1 muscle group). Your best bet is to do squats, deadlifts, and bench press. Try using heavy weights doing 3 sets of 5 reps.
Simply treading water for extended periods of time can help build muscle strength, as well as increase your cardiovascular fitness. While not as strenuous as doing intense swimming, treading water is a suitable water exercise for people of all ages.