Dietary nitrates are associated with enhanced muscle efficiency, fatigue resistance, and aerobic performance. Most studies assessing nitrates look at beetroot juice, because it’s such a rich source, but it is an acquired taste. Luckily, there’s another particularly rich source: amaranth. In a recent study, when young male participants were given amaranth for six days, aerobic capacity was significantly improved. This gluten-free ancient grain is high in protein, fibre, and countless other micronutrients and antioxidants. Find it in your nearest health food shop.