Hydration Is a Performance Variable

Most hydration advice is either too vague to act on or too aggressive to need. "Drink more water" is not a protocol. Neither is treating every training session as an electrolyte emergency.

The useful version sits between those, and it has numbers attached.

The threshold that matters

The American College of Sports Medicine's position stand on exercise and fluid replacement puts the line at two percent. Dehydration greater than two percent of body mass can degrade aerobic exercise performance — particularly in warm or hot conditions.

Two percent is less than it sounds. For someone at 170 pounds it is a little over three pounds of fluid, which is an ordinary loss across a hard hour in the heat.

It is also measurable without equipment. Weigh yourself before a session and after it, unclothed and towelled dry. The difference is almost entirely water. If you are routinely down more than two percent, you are training on the wrong side of that line.

Water is not always enough

Sweat is not just water. It carries sodium, and over long sessions the sodium loss becomes the constraint rather than the volume.

Replacing heavy fluid loss with plain water alone dilutes what is left. That is the mechanism behind exercise-associated hyponatremia, which is rare but genuinely dangerous, and which is caused by drinking too much water rather than too little.

When electrolytes earn their place

The ACSM guidance is specific here too. It recommends including sodium in the range of 0.5 to 0.7 grams per litre of fluid consumed during exercise lasting longer than one hour, on the grounds that it improves palatability, promotes fluid retention, and may help prevent hyponatremia.

Read the condition carefully: longer than one hour. Below that, for most people in most conditions, water is the correct answer and an electrolyte drink is a preference rather than a requirement.

The threshold moves with heat, humidity, and how heavily you sweat. It does not move down to twenty minutes in an air-conditioned gym.

A practical protocol

Start sessions already hydrated rather than trying to catch up mid-effort. Drink to thirst during exercise instead of to a schedule — thirst is a better-calibrated signal than most people are told. Add sodium when a session runs past an hour, when it is hot, or when you finish sessions with salt visible on your skin.

Then check yourself against the scale occasionally rather than guessing.

What we make

Our Hydration Complex is a powder in three flavours — peach mango, passion fruit, and lemonade. It is built for the case above the one-hour line: long sessions, hot conditions, heavy sweat.

For a half-hour indoors, water is fine. We would rather say that than sell you a scoop you do not need.