Many people make excuses not to exercise.  Well, depending on your workout you just might have one.  Daily Health Post has a list of five exercises that aren't worth doing.

1.  Planking.  This is the ab exercise where you hold your body rigid and prop yourself up on your elbows.  But unless you're a pure beginner, it doesn't do anything.  You need more resistance to give your torso a real workout.

2.  Crunches.  They only target one small set of your abs.  And they put too much strain on your neck and back if you don't carry out your form perfectly.  So you're better off using some kind of tool, like a balance ball.

3.  The Bench Press.  It works, but it's overrated.  You need other a variety exercises to get a complete arm and chest workout.  So some trainers recommend using dumbbells instead, and focusing on inclines and military presses. Ladies, when I say dumbbells I am not speaking of your husbands...

4.  The seated knee extension.  It's when you sit on a weight machine with your legs bent, and lift weights with your feet until your leg is completely horizontal.  It works your quads, and that's it.  You're better off doing a full-body exercise, like lunges or squats.

#5.)  Hanging knee raises.  That's where you hang between two bars and curl up your knees to your chest.  This one is pretty hard to do correctly, so it's easy to get hurt.  Just do bicycles instead . . . lying on your back and kicking as if you're pedaling a bike.