Water is the single most important thing to drink before a workout, but the timing and amount matter more than most people realize. Losing just 2% of your body weight in fluid can measurably hurt endurance performance, especially in the heat. Beyond water, a few other drinks, from coffee to beetroot juice, can give you a real edge if you use them correctly.
Water: How Much and When
The simplest guideline is to drink about 17 ounces (500 ml) of water roughly two hours before you exercise. That window gives your body enough time to absorb the fluid and let your kidneys flush out the excess, so you’re not starting your workout needing to use the bathroom. On top of that, you should be eating balanced meals and drinking fluids consistently throughout the day leading up to your session, particularly with whatever meal comes closest to your workout.
A quick way to check whether you’re hydrated enough is to glance at your urine. Pale, nearly clear urine (a 1 or 2 on the standard 8-point color chart) means you’re in good shape. If it’s medium yellow (around a 3 or 4), drink a glass of water. Anything darker than that and you’re already dehydrated enough that it could affect your performance.
Don’t Overdo It
Drinking too much water before and during exercise is a real risk, not just a theoretical one. When you take in far more fluid than you lose through sweat, your blood sodium levels drop, a condition called exercise-associated hyponatremia. In serious cases it can cause confusion, seizures, or worse. The general rule: during exercise, keep fluid intake between 500 and 1,200 ml per hour depending on your body size and how much you’re sweating. Before exercise, drink to satisfy thirst rather than forcing fluids, and never drink so much that you actually gain weight. Thirst remains the best real-time gauge of what your body needs.
Coffee and Caffeine
Caffeine is one of the most reliably effective performance boosters available, and a cup of coffee is the easiest way to get it. It reaches peak concentration in your blood about 60 minutes after you consume it, so drinking coffee an hour before your workout lines up perfectly with its pharmacology.
The dose that consistently improves short-term power and endurance in research is around 3 to 6 mg per kilogram of body weight. For a 150-pound (68 kg) person, that works out to roughly 200 to 400 mg of caffeine, or about two to four cups of brewed coffee. A moderate dose (closer to 3 mg/kg) is a smart starting point. Studies on female team-sport athletes found that 6 mg/kg optimized short-term maximal performance while keeping side effects low, but jumping straight to 9 mg/kg actually increased jitteriness and nausea without improving results further. More isn’t better here.
If you’re not a regular coffee drinker, start on the lower end. Caffeine’s side effects (anxiety, a racing heart, stomach upset) are dose-dependent, and people who rarely consume it are more sensitive.
Beetroot Juice
Beetroot juice has become a popular pre-workout drink for endurance athletes, and the science backs it up. The benefit comes from its high nitrate content. Your body converts dietary nitrate into a compound that widens blood vessels, improving oxygen delivery to working muscles and lowering the energy cost of exercise.
The effective dose is 6 to 8 millimoles of nitrate, which translates to roughly 500 ml (about 16 ounces) of beetroot juice, or a smaller volume of a concentrated “shot” product designed for athletes. Blood levels of the active compound peak about 2 to 3 hours after you drink it, with measurable performance benefits appearing around 90 minutes to 2.5 hours post-ingestion. So if your workout starts at 6 PM, drink your beetroot juice around 3:30 to 4:00 PM.
One practical note: avoid using antibacterial mouthwash around the time you drink beetroot juice. The bacteria on your tongue play a critical role in converting nitrate into its active form, and antiseptic rinses kill those bacteria, blunting the entire effect.
Carbohydrate Drinks
If your workout will last longer than 60 to 90 minutes, or if you’re training at high intensity, a carbohydrate drink before and during exercise can delay fatigue. Sports drinks, diluted fruit juice, or a homemade mix of water with sugar and a pinch of salt all work.
The key is concentration. The more sugar you pack into a drink, the slower it empties from your stomach, which can leave you feeling bloated or nauseous during hard exercise. A drink in the 4 to 8% carbohydrate range (roughly 4 to 8 grams of sugar per 100 ml) is a reasonable target for most people. Drinks that blend two types of sugar, like glucose and fructose, empty from the stomach faster and absorb more efficiently than drinks with only one sugar source. That’s why many commercial sports drinks use this combination.
For shorter or lower-intensity sessions, plain water is enough. You have plenty of stored carbohydrate in your muscles and liver to fuel a 45-minute strength workout or a casual jog.
Protein and Amino Acid Drinks
A protein shake before training is less about immediate energy and more about giving your muscles a head start on repair. Whey protein mixed with water is the most common choice, but research from the Journal of the International Society of Sports Nutrition found that a blend of free essential amino acids combined with whey protein stimulated muscle protein building at roughly three to six times the rate of whey protein alone on a gram-for-gram basis. A whey-only drink at a comparable dose didn’t even produce a statistically significant increase in muscle protein synthesis in that study.
If maximizing muscle growth is your primary goal, look for a pre-workout drink or supplement that contains essential amino acids alongside whey, rather than whey by itself. A dose of about 10 to 15 grams of protein or amino acids 30 to 60 minutes before training is a common recommendation in sports nutrition practice.
Adding Sodium for Heavy Sweaters
If you sweat heavily, train in the heat, or are preparing for a long endurance event, adding sodium to your pre-workout fluid can help your body hold onto more water. In one study, athletes who consumed a larger sodium load before exercise drank 68% more fluid voluntarily and retained a greater proportion of what they consumed. The sodium triggers thirst and reduces how much fluid your kidneys excrete, effectively expanding your blood volume before you start losing sweat.
You don’t need a special product for this. Adding a quarter to half a teaspoon of table salt to 16 ounces of water, or drinking a broth-based soup with your pre-workout meal, accomplishes the same thing. Commercial electrolyte tablets or powders work too. This strategy matters most for sessions lasting over an hour in warm conditions. For a quick gym workout in an air-conditioned room, plain water and a normal diet provide all the sodium you need.
Putting It All Together
Your pre-workout drink strategy depends on how long and hard you plan to train. For a standard gym session under an hour, 17 ounces of water two hours beforehand and a cup of coffee an hour out covers you well. For longer endurance work, layer in a carbohydrate-electrolyte drink and consider beetroot juice if you want an extra edge. Check your urine color as a quick hydration gut check, and let thirst guide you rather than forcing a rigid schedule. The goal is to start your workout hydrated, fueled, and comfortable, not waterlogged.