You don't need to run marathons to run low on electrolytes. Heavy training, hot weather, saunas and even long days of coffee-fuelled work all nudge your fluid balance in the wrong direction. Here are five common signals.
1. Muscle cramps and twitches
The classic sign. Sodium, potassium and magnesium all play roles in muscle contraction; when they dip, cramp risk climbs — particularly in calves and feet at night or late in long sessions.
2. Headaches after training
A post-gym headache is often a fluid-and-sodium issue rather than anything sinister. Rehydrating with electrolytes rather than plain water usually resolves it faster.
3. Feeling flat despite sleeping well
Mild dehydration reliably drags down energy and concentration before you ever feel thirsty. If afternoons feel foggier than your sleep justifies, fluids are the first thing to check.
4. Dark urine
Aim for pale yellow. Consistently dark urine is your simplest everyday hydration gauge (some vitamins can brighten it — that's harmless).
5. Heavy, salty sweat
White marks on dark training kit mean you're a salty sweater and lose sodium faster than most — exactly who electrolyte products are designed for.
Easy fixes
Keep a tube of Applied Nutrition's Bodyfuel Effervescent Tablets by your water bottle, use Hydration+ or Naughty Boy's Hydration powder on training days, or grab an Na11 can when you're out and about. For long endurance work, their Endurance Hydration Tabs are made for the job. See the full Hydration collection.
This article is for general information only. Persistent symptoms deserve a conversation with your GP.