"When most people think about cardiovascular risk factors and risk behaviors, they don't necessarily think of sleep," said Dr. Brian McCrindle, senior author and cardiologist at SickKids in Toronto, Ontario. "This study ... shows a clear association between sleep disturbance (in adolescents) and a greater likelihood of having high cholesterol, high blood pressure and being overweight or obese."

Fitness trends-and all the stuff that comes with them-come and go, but every year there are some standout products that are truly effective. Dive into our top 15 that promise to deliver results (and do more than collect dust).

The fastest way to six pack abs is targeting excess body fat by working several muscle groups together. This speeds-up belly fat loss by raising metabolism and lowering calorie-storage.

Getting a lean, well-defined abdomen is not as hard as most people think. It just takes the proper knowledge and some good old perspiration.

Running is the best example of fat-burning functional exercise know to man. For those who find it difficult to run regularly, metabolic resistance training can also give the cardio system a good workout and develop muscles at the same time