For many stretches of my life as a gym rat, I have been a hydro-hater. It wasn’t just because I always shared the opinion of Bob Belcher that water is, in fact, “stupid juice.” But also because I often eschewed any organized forms of cardio. And so, my sole need was to fuel my resistance workouts — usually through caffeine-packed energy drinks — and then bolt straight home.
However, I’m now afraid that I may have been doing myself a grave disservice, handicapping my strength training by being functionally dehydrated through nearly all of it. Just because no obvious, observable fluids (namely: sweat and minerals) were leaving my body while I was knocking out pull-up sets, that doesn’t necessarily mean I wasn’t getting dehydrated in the process (an energy drink, of course, doesn’t exactly bring with it the same benefits as water).
Does lifting weights dehydrate you?
Indeed. Your body loses moisture every time you exhale, with most experts estimating the total amount of water lost each day exclusively to breathing at somewhere between one and two cups. Needless to say then, any form of proper weightlifting is going to boost the rate and force of your exhalation, and accelerate this process. Moreover, resistance exercise will eventually make you perspire if you engage in it long enough, either as a result of your body heating up from exertion or the temperature of the gym.
That said, you’ll never lose nearly the amount of fluids from weightlifting as you will through the sort of cardio that causes excessive sweating. Thus, you’ll probably not find yourself feeling uncomfortably dehydrated, at least not in a way that’s going to leave you noticeably compromised.
Does that mean I don’t have anything to worry about if I’m not hydrating when I lift weights?
No, hydration definitely still matters.
Several studies have demonstrated that an absence of adequate hydration during resistance training is linked to a predictable loss of strength. In other words, simply by approaching a strength workout without sufficient fluids in your system, you’re reducing your peak output potential. You’re also crippling the quality of your recovery, as your broken-down muscle fibers are at risk of not having their proteins replenished in the absence of water.
I’m not saying you have to become a hydro-lover, or that you need to reconsider any long-held belief that water is stupid juice. But it certainly wouldn’t hurt (and most likely, would very much help) to take more than a few swigs as you’re pumping all that iron — whether you’re working up a sweat or not.