Plain water covers most workouts under an hour, but sessions past 60 minutes call for a drink with 4%–8% carbohydrate and sodium to hold energy and fluid balance.
Most people reach for a bottle and never think about what’s in it — then wonder why mile eight feels so much harder than mile two. The right call for what to drink during a workout for energy depends on one number: how long you’re moving. Below is what the American College of Sports Medicine (ACSM) and the National Athletic Trainers’ Association (NATA) actually recommend, broken into water versus sports drink, exact amounts, and where people go wrong.
Water Or A Sports Drink: Which One Do You Need?
Water is enough for exercise lasting less than 1 hour, because research shows little performance difference between a carbohydrate-electrolyte drink and plain water in that window. Past 1 hour, adding carbohydrate and electrolytes is recommended — ACSM notes it can help performance without significantly slowing fluid delivery.
Reach for the sports drink when any of these apply:
- The session runs longer than an hour, or you’re doing repeated hard efforts.
- Conditions are hot or humid, so sweat losses climb.
- You sweat heavily or your clothes are soaked through by the halfway mark.
- You’re training on back-to-back days and need to replace sodium, not just water.
For a brisk 30-minute walk in mild weather, plain water wins — no contest, no cost.
How Much And How Often Should You Drink?
Start early and sip at regular intervals rather than waiting for thirst. NATA’s guidance is 7–10 oz every 10–20 minutes during exercise, and ACSM recommends drinks cooler than ambient air — 59°F–72°F — and flavored, because people simply drink more when it tastes good.
Before you start, ACSM recommends about 17 oz roughly 2 hours out. NATA’s handout spreads it a little wider: 17–20 oz 2–3 hours before, then another 7–10 oz 10–20 minutes before the first step. Afterward, replace each pound of body weight lost with 16–24 fl oz, and get the total in within 6 hours.
Cooler and flavored matters more than most people think — a tepid, tasteless bottle tends to sit untouched, and untouched fluid does nothing for you.
What Should The Drink Actually Contain?
Look for two numbers on the label: carbohydrate in the 4%–8% range and real sodium. ACSM says a solution in that carb range delivers energy without compromising fluid delivery, and calls for 0.5–0.7 g of sodium per liter of rehydration fluid for exercise past 1 hour. During intense work lasting more than an hour, the ACSM target is 30–60 g of carbohydrate per hour.
| Workout Situation | What To Drink | Target Per Hour |
|---|---|---|
| Under 1 hour, easy pace | Plain water | Sip to thirst, 7–10 oz every 10–20 min |
| Under 1 hour, hot and humid | Water; sports drink optional | Same fluid pace, sodium helpful |
| 1–2 hours, steady effort | 4%–8% carb sports drink | 30–60 g carb, 0.5–0.7 g sodium per liter |
| 2+ hours endurance | Carb-electrolyte drink plus food | 30–60 g carb per hour, sodium per sweat rate |
| Heavy sweater, any duration | Sodium-containing drink | Match fluid to sweat loss, never exceed it |
| Back-to-back training days | Carb-electrolyte drink | Replace 16–24 fl oz per lb lost |
| Cool-weather easy session | Plain water | Sip regularly, smaller volumes |
Common Mistakes That Drain Your Energy
Drinking too much is the mistake nobody expects. ACSM warns that fluid intake during exercise should not exceed sweat loss; overdrinking dilutes blood sodium and raises the risk of hyponatremia, a genuine medical emergency. Sodium in your drink helps the body retain fluid and may lower that risk in people who drink large volumes.
The other slip is assuming every “electrolyte drink” is built the same. Many products miss the 4%–8% carbohydrate range with meaningful sodium that sports nutrition guidance points to. Check the label rather than the front of the bottle.
Sweat rate and sweat sodium swing widely from person to person, so treat every number here as a starting point and adjust from what your own sessions teach you. If you want tested options instead of label math, this roundup of drinks for boosting workout intensity compares formulas side by side.
The ACSM position stand remains the anchor document behind these targets: ACSM’s exercise and fluid replacement position stand.
FAQs
Is water enough for a 45-minute gym session?
Yes, for most people. Research shows little performance difference between a carbohydrate-electrolyte drink and plain water for exercise under 1 hour. Drink 7–10 oz every 10–20 minutes and you’re covered. If the gym is hot, you sweat heavily, or you’re doing repeated hard sets, a sodium-containing drink may help you feel better.
Can I just drink water and eat a banana instead?
Often, yes. Solid food and water can supply carbohydrate and some electrolytes for longer sessions, and many athletes alternate them. The trade-off is digestion speed and convenience during hard efforts — liquid carbs empty from the stomach faster, which matters when you’re breathing hard and can’t chew comfortably.
How do I know if I’m drinking too much?
Watch for bloating, sloshing in your stomach, or weight gain after a session. ACSM guidance says fluid intake during exercise should never exceed sweat loss. Weighing yourself before and after a workout is the simplest check — if you finish heavier than you started, you drank more than you lost.
References & Sources
- American College of Sports Medicine. “Exercise and Fluid Replacement Position Stand.” Source for the 30–60 g carb per hour, 0.5–0.7 g sodium per liter, and fluid temperature guidance.
- ACSM Current Sports Medicine Reports. “Sports Drinks, Exercise Training, and Competition.” Supports the 4%–8% carbohydrate drink range and fluid delivery findings.
- Australian Sports Commission. “Sports Drinks.” Background on carbohydrate-electrolyte drink composition for training and competition.