Try this food to work out longer

Beet energy

Beetroot juice, a source of the nitrate molecule, definitely increases your endurance during exercise and can make you train longer. A clinical study published in the American Journal of Physiology — Regulatory, Integrative and Comparative Physiology found that people who drank 4-5 tablespoons of beetroot juice for 15 days had lower blood pressure and more dilated blood vessels both at rest and during exercise.

Blood vessels also dilated more easily and the heart consumed less oxygen during exercise. The researchers said the findings suggest that beetroot juice can act as a dietary nutraceutical (a cross between a nutritional supplement and pharmaceutical), capable of “enhancing oxygen delivery and reducing work of the heart such that exercise can be performed at a given workload for a longer period of time before the onset of fatigue.”