Why hydrate during every run?
Author - team nerd
The goal of drinking during exercise is to avoid excessive dehydration. Studies show, your body can handle only 2% of body weight loss (sweat loss) during exercise before your performance is impacted.
Runners are often shocked when we state sweat losses are between 1-3L per hour at tempo or moderate paces (high zone 2 - low zone 3). However, even team nerd was shocked recently when we conducted a mini case study with replies from 92 customers who sent us their sweat
loss per hour during an aerobic run.
The average sweat loss at an aerobic (zone 1 or low zone 2) were 1.25L per hour.
So when does performance start to drop off? We used Steve (Head nerd) as an example:
- Steve weighs 68kg
- 2% of Steve's body weight is 1.3L
So even on an aerobic run, if he sits on the average sweat loss per hour, his performance, RPE, heart rate stability will all drop off after only 1 hour without hydration during an easy run.
This is why Steve hydrates on every single run and drinks 800ml per hour in a marathon....
IMAGINE HOW QUICK THE AVERAGE RUNNER WILL LOSE 2% OF THEIR BODY WEIGHT AT RACE PACE IF IT ONLY TAKES 1 HOUR AEROBICALLY TO SEE SIGNIFICANT PERFORMANCE DROPS?!??!?
So why do we hydrate on every single run?
If we finish every run in a small (or large) deficit day after day, then the accumulative deficit on day 5-7 could be significant. Performance drops a few days in and 5+ days of consistently failing to chase your hydration losses increases injury risk, lowers power and strength, which affects performance overall with consistency now at risk...
CONSISTENCY IS KEY.
Hydrate on every run.
Supporting information
American College of Sports Medicine position stand. Exercise and fluid replacement
American College of Sports Medicine; Michael N Sawka, Louise M Burke, E Randy Eichner,
Ronald J Maughan, Scott J Montain, Nina S Stachenfeld
There’s also a really good, easy-to-read summary here:
“Marathon Hydration, Solved: The Exact Fluids, Carbs, and Sodium You Need.
