Have you ever timed how long it takes to go to the bathroom?

Just FYI, it takes at least 2 minutes to take a leak, assuming close proximity of the restroom and that you wash and dry your hands.

Two minutes may not sound like much, but it can seem like an eternity if you’re in the middle of an intense practice session, rehearsal, or even if you’re trying to cram a ton of errands and chores into an afternoon.

We’ve all been told how important it is to stay properly hydrated, and have read those miracle stories about how water will help us look 10 years younger.

But drinking more water means going to the bathroom more often. And going to the bathroom is a bit of a hassle (or am I the only crazy one here?).

So is all the pro-water talk just a bunch of marketing hype for a multi-billion-dollar industry? Or is staying hydrated actually worth the effort when it comes to practicing more effectively and performing better when it matters?

Levels of dehydration

We know that severe dehydration – defined as a loss of body water of more than 5% – can be pretty serious. Serious, as in delirium, unconsciousness, and even death.

But that’s not very typical, and is going to take way more than playing even the longest symphony ever (Havergal Brian’s Symphony No. 1 “The Gothic”), which clocks in at almost 2 hours.

Reaching a state of mild (1%-2%) or moderate (2%-5%) dehydration on the other hand, is pretty easy, and can occur in the course of a normal day’s activities. We don’t really start getting thirsty until we have lost 1%-2% of our body water, so many of us are probably mildly dehydrated for at least part of each day.

Mild/moderate dehydration and physical performance

When it comes to classic athletic indicators like strength, power, and speed, it’s been estimated from the results of a variety of studies that a 2% loss of body water can result in a 20% decline in performance.

That seems like a pretty significant performance hit, but the degree to which this is important for musicians would depend on the particular physical demands of one’s instrument.

On the other hand, the impact of mild to moderate dehydration on one’s cognitive performance is likely to be of interest to musicians across the board.

Dehydration and cognitive performance

Cognitive performance can be tricky to measure, but researchers have found several things that are intriguing and relevant to musicians.


At 1%-2% dehydration, there doesn’t seem to be much of a drop in performance on tasks testing our ability to pay attention. Go beyond 2%, however, and performance does begin to drop.

Motor skills

Losing 2% or more of body water also has an impact on motor functioning. A study of cricket players found that at 2.8% dehydration, the velocity of their deliveries remained the same, but the accuracy of the line and length of their bowls was reduced by 15%.

A study of golfers found that at 2% loss of body water, shot distance decreased from an average of 128.6 meters to 114.4 meters. But more importantly, shot accuracy degraded from an average of 4.1 meters from the intended target to 7.9 meters from target.


Other studies have also found losses of around 2% of body water to contribute to headaches, difficulty concentrating, and fatigue as well – all of which would make it more difficult to be productive in the practice room and at one’s best on stage.


Perhaps the most intriguing finding comes from a recent King’s College London study, where researchers compared the brain activity and cognitive performance of 10 participants when properly hydrated and then in a dehydrated state.

On the surface, being dehydrated didn’t seem to matter much. The participants performed a test of executive functioning called the “Tower of London” task (try your hand at it here), and being dehydrated didn’t have a significant impact on performance.

However, having to perform the task when dehydrated led to a marked increase in neural effort in a part of the brain which is known to be required for complex thinking. In other words, when dehydrated, the participants’ brains had to work harder to achieve the same level of performance as when they were hydrated.

The implication being, given that energy and willpower is a limited resource, you’re more likely to bonk and start seeing your performance decline sooner than someone who is better hydrated.

It does mean having to go to the bathroom more often (or holding it in, though that’s probably not great for concentration or performance either), but it’s kind of silly to make ourselves work harder when a drink of water can make things a bit easier on our poor overworked brain.

Take action

So, the next time you have a headache, are feeling tired, cranky, or just not in the mood to practice, go drink a glass of water, maybe even add a 10-20 minute power nap, and see how that changes things.

Just keep in mind that more doesn’t always mean better. The answer is not to drink as much water as possible. There is such a thing as drinking too much water (though that too is not so common).

For more on the impact of dehydration on performance, check out this review of the literature here: Cognitive Performance and Dehydration

photo credit: AlphaTangoBravo / Adam Baker via photopin cc