Poor exercise form or bad workout habits are costing you precious calories. Fitness experts reveal the most common ways people cheat at their workouts without even realizing it, and offer ways to kick those saboteurs to the curb on Fox News channel.

1) You're a swinger

Momentum comes in handy when you're attempting a long jump, but not if you're lifting weights. Each exercise involves two phases: a concentric (contracting) move and an eccentric (stretch) phase.

"Building momentum by swinging your arms when doing a move like a bicep curl or a tricep push-down sacrifices results by not controlling the eccentric phase, and also increases your risk of injury," said Irv Rubenstein, exercise physiologist and founder of STEPS Fitness, a science-based fitness facility in Nashville, Tenn. Practice a two-second count on the concentric move and four to five count on the eccentric.

2) You hold on for dear life

Grasping the sidebars when walking on the treadmill or hanging on tight to the handles of the elliptical trainer cheats you out of the largest possible calorie burn, Rubenstein said.

"Instead, use the rails only as a guide, keeping your fingertips lightly on them. If you find it impossible to maintain proper form without clutching the bars, try lowering the incline or slowing down your pace''.

3) You play the waiting game

 Few things are more frustrating than dealing with a crowded gym, especially when other exercisers occupy the machines and equipment you'd planned on using. But waiting around wastes valuable time, said Tom Holland, exercise physiologist.

"Don't wait for the equipment to be available-instead, fill time with exercises you can do without a machine, such as crunches, planks, or push-ups," he said.

4) You stretch between exercises

Stretching between exercises could sacrifice your ability to perform your remaining exercises, said Rubenstein. Leave stretches to the end as part of your cool down.

5) When the going gets tough, you stop

 Simply showing up isn't enough if you don't put any real effort behind your moves, said Holland.

6) You arrive to class late or leave early

Skipping out on the warm-up or cool-down means you're missing a couple of crucial components of the class experience, said Jessica Matthews, assistant professor of exercise science at Miramar College in San Diego, Calif..

7) You're a bookworm

If you're reading this article while you're on the treadmill, you're not working hard enough, said Holland.

"If you can read, text, or otherwise give your attention to some other non-workout related issue, you're cheating yourself."