“It’s amazing what your body can do when you give what it needs.”
Proper nutrition mid-race, if your distance calls for it, is just a critical as pre- and post-run nutrition. As you gradually train to match the distance of your race, you should also train for how to fuel your body during that distance.
If your race is under 60 minutes and you fuel and hydrate properly beforehand, you will not necessarily need to take in any more calories or fluid while you’re running. If you are training for a longer effort, however, it will be key to use your training runs to practice consistent fueling and hydration. Additionally, it’s always a good idea to know what food and hydration products will be offered at aid stations on the course and, if possible, train with those products; this information is usually available on race websites.
During your longer training runs, get on a consistent fueling schedule by setting your watch timer for 20-30 minute intervals at which you take in calories and hydrate; you can either use this same strategy during your race or just plan on stopping at regularly spaced aid stations. Practicing race day nutrition during your training will also allow you to fine tune the amount and type of calories your body can handle while running. Unless you’ve been actively working to train your body to burn fat while running, you should generally aim on consuming 120-240 calories (30-60g of carbs) per hour of running. This range is dependent on many factors including runner size, run duration, and race intensity. And where you fall in this range should be something that you determine before showing up to the starting line.
In addition to figuring out how much to eat, figuring out how much to drink is also something to work on in advance of your race. Essentially, the goal is to replace what is lost through sweat, so run hydration should be about both fluid and electrolyte replacement. A good first step, and something you can do at home, is to determine your sweat rate or the amount of water lost via sweat in a given amount of time (typically an hour). For the specifics on how to effectively do a sweat test, visit http://gognarly.com/gnarly-hydration-test/. Many factors, including temperature, humidity and aerobic output, can impact sweat rate, so when measuring sweat rate, it’s important to replicate the conditions you will experience on race day as closely as possible.
Taking in the right amount of water will get you halfway to properly hydrating, but if that is all you do then your performance will suffer and you could seriously injure yourself. The other half of the equation involves replenishing the electrolytes lost in sweat. Determining the amount of electrolytes lost in sweat is a little more involved and requires a sweat test which can be administered in performance labs. Much like sweat rate, the electrolyte content of sweat is dependent on many factors and can vary greatly from person to person. Although sodium, potassium, calcium, and magnesium are all lost in sweat, sodium is, by far, lost in the greatest concentrations, with losses ranging from 200-700 mg in 16 oz of sweat. Electrolyte replacement should focus on replenishing lost sodium, and to a lesser degree, replacing lost potassium, calcium and magnesium. By choosing a hydration beverage that contains electrolytes at effective levels, you ensure you’re giving your body both the water and electrolytes it needs to perform optimally, while preventing cramping and dehydration.
Mid-Run Break Down
– Hydrate and take in calories every 20-30 minutes
– 120-240 calories (30-60g of Carbs)/hour of running
– Carry out sweat rate test to zero in on the amount of fluid to consume
– Choose electrolyte beverage that replenishes lost sodium, potassium, calcium, & magnesium
Good nutrition is fundamental to a healthy body and sets the stage for competitive performance. Following these guidelines will give you greater insight into what your body needs mid-run and what amazing things your body can do when you give it what it needs.