Go for endurance

Find yourself getting tired about halfway through your workout? Eat an apple before going to the gym.

A recent study shows that by eating apples, elderberries, fennel and red onions - all great sources of the super-antioxidant quercetin - you may improve overall endurance by 13%.

The University of South Carolina study found that when 12 college-age volunteers increased quercetin intake over the course of a week while being tested for exercise endurance on stationary bikes, they not only improved their oxygen uptake by 4%, they were able to ride 13% longer before becoming fatigued.