The act of loading up on fluids and electrolytes to pump up your blood volume before exercise. “It allows you to stay hydrated/avoid dehydration in extreme exercise circumstances,” says Stacy Sims, PhD, senior research scientist at the University of Waikato in New Zealand.
WHEN TO DO IT Taking in this much sodium can cause bloating and discomfort; it may also raise your blood pressure and strain your cardiovascular system. Save it for the hardest rides in extreme conditions, like three-plus hours in high heat, or racing at altitude. It can also help women who have a big event during PMS, when hormone shifts cause blood plasma volume to drop. As with all hydration and nutrition strategies, test it out before an event.
HOW TO DO IT
Look for packaged hyperhydration products including Osmo Preload Hydration (for men and women) and Skratch Labs Hyper Hydration. Or try Nuun Electrolytes Hydration Tablets (3 in 500ml water the night before; 6 in 500ml water the morning of). Be warned: hyperhydration is salty; the taste is strong.