CrossFit Nutrition and Supplements: What to Eat and What Works

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Ask ten people at the box what they eat and you’ll get ten answers: someone weighing chicken and rice into containers, someone doing Paleo, someone counting Zone blocks, someone who just eats whatever’s in the fridge after the 6 p.m. class. CrossFit nutrition has a strong culture, and a lot of opinions. This page sorts it out: what CrossFit itself recommends, what the big sports-nutrition bodies say athletes doing high-intensity training need, how to eat around workouts, and which supplements for CrossFit have real evidence, with third-party tested picks.

Prices change often. The prices below are what we saw at the maker or a major retailer in October 2026; check the current price before you buy.

What CrossFit recommends

CrossFit’s Level 1 Training Guide puts its advice in one line: “Eat meat and vegetables, nuts and seeds, some fruit, little starch, and no sugar. Keep intake to levels that will support exercise but not body fat.” The guide also points to the Zone Diet as its most precise option. The core message, built around real food and good-quality protein, is sound for most people.

Where many sports dietitians would add a footnote is carbohydrate. “Little starch” can leave hard-training athletes short of fuel, especially those training more than once a day or competing. CrossFit workouts are short and intense, and that kind of effort runs mostly on carbohydrate stored in the muscles. So if you’re training hard and feeling flat, under-eating carbs is one of the first things to look at.

What sports nutrition research says

The 2016 joint position of the American College of Sports Medicine (ACSM), the Academy of Nutrition and Dietetics and Dietitians of Canada is the standard reference. Its daily guides, per kilogram of body weight:

• Carbohydrate: about 3–5 g/kg on light or skill-based days, 5–7 g/kg for about an hour a day of moderate exercise, and 6–10 g/kg for 1 to 3 hours a day of moderate to high-intensity training. A typical one-hour class sits in the middle; a competitor doing two sessions a day sits higher.
• Protein: about 1.2–2.0 g/kg a day, spread over meals, with 15–25 g after hard training.
• Enough total energy. Eating too little for the training you do can hurt performance, health and recovery, a risk for athletes trying to lose weight fast while training hard.

In real meals: a protein source at every meal (eggs, Greek yogurt, meat, fish, beans, tofu), lots of vegetables and fruit, and carbohydrate (rice, potatoes, oats, bread, pasta) matched to the day: more on heavy training and competition days, less on rest days.

Around your workouts

• Before: a normal meal 2–4 hours before class, or a small, easy snack (banana, toast, yogurt) if you train early. ACSM suggests carbohydrate in the hours before exercise and less fat and fiber close to the start.
• During: a one-hour class rarely needs more than water. Two-a-days and competitions are different; see CrossFit competition day.
• After: protein plus carbohydrate in the next few hours: a real meal, or a shake and fruit if dinner is a while off. More in our CrossFit recovery routine.
• Fluids: start hydrated and aim to lose no more than about 2% of body weight in sweat. Heavy sweaters and hot gyms may want an electrolyte drink.

Teens and CrossFit nutrition

Teens who train are still growing, so the priority is enough food, not a restrictive diet. The American Academy of Pediatrics (AAP) advises against creatine and other performance supplements for young athletes and says energy drinks have no place in their diet. For teens, three good meals, snacks around training and water are the plan. More in CrossFit for kids and teens.

Supplements for CrossFit: what the evidence says

The IOC’s 2018 consensus statement on dietary supplements and the high-performance athlete starts with “food first”, then names a short list of supplements with good evidence for performance in some situations. For CrossFit, that sorts out like this:

• Protein powder: a convenience. Food can cover your needs. A shake is useful when a meal isn’t practical, like right after the 6 a.m. class.
• Creatine: some of the best evidence, for adults. It’s one of the most studied supplements, and the IOC group lists it among those with good evidence, especially for repeated high-intensity efforts and strength training. The IOC notes it can add 1–2 kg of body weight, mostly water. Not for under-18s, per the AAP.
• Caffeine: a small edge for some. A 2026 meta-analysis of seven CrossFit studies found a small performance benefit. It isn’t for everyone: it can cause anxiety, a racing heart, stomach upset and poor sleep (bad news for 6 p.m. classes). Not for teens; ask a doctor first if you have a heart condition or are pregnant. Many pre-workouts contain a lot of caffeine; check the label and our best pre-workout guide.
• Beta-alanine and sodium bicarbonate: the IOC group also lists these with good evidence for hard efforts from about 30 seconds up to around 10 minutes, which describes many WODs. Both have side effects (temporary tingling skin or rashes with beta-alanine, stomach upset with bicarbonate) and are best tried with a sports dietitian, not on competition day.
• Electrolytes: a sports food, not a magic potion: handy for hot, long or double sessions.
• Vitamins and minerals: a multivitamin can fill gaps in a restricted diet, but test before you take things like iron or vitamin D in high doses. Ask your doctor for a blood test first.

Why third-party testing matters

Supplements can contain things that aren’t on the label. One study cited by sports-nutrition experts found that about 15% of 634 supplements from 13 countries contained undeclared prohormones. If you compete at a level with drug testing, “I didn’t know” doesn’t count. Programs like NSF Certified for Sport and Informed Sport test products for banned substances. They lower the risk without removing it, and they don’t test whether a product works. That’s why every pick below is certified.

Our top picks

Product	In one serving	Certification	About (Oct 2026)	Per serving
Thorne Whey Protein Isolate	21 g protein	NSF Certified for Sport	$65 / 30 scoops	about $2.17
Thorne Creatine	5 g creatine monohydrate	NSF Certified for Sport	$44 / 90 scoops	about $0.49
Thorne Advanced Electrolytes	600 mg sodium, 200 mg potassium, 15 g carbs	NSF Certified for Sport	$39 / 20 scoops	about $1.95
Nuun Sport	300 mg sodium, 150 mg potassium, 1 g sugar	Informed Choice	$7.49 / 10 tablets	about $0.75
Klean Multivitamin	2 tablets; 1,000 IU vitamin D	NSF Certified for Sport	about $46 / 30 servings	about $1.53

Why these: each is on a sport-testing list, and together they cover what CrossFit athletes actually use. Thorne Whey is a simple 21 g protein shake for after class. Thorne Creatine is plain creatine monohydrate with nothing else added. Thorne Advanced Electrolytes carries more sodium plus some carbohydrate for hot gyms and competition days, while Nuun Sport is the cheap, low-sugar tablet for everyday bottles. The Klean Multivitamin is a basic insurance policy without iron. For more choice, see our guides to protein powder, creatine and electrolyte powders.

Check the Thorne Creatine price on Amazon

Talk to a professional. Before starting any supplement, check with your doctor or a registered sports dietitian, especially if you’re under 18, pregnant, take medication, or have a heart, kidney or other medical condition. Follow the label; this page doesn’t give doses beyond it.

Back to the CrossFit hub, or keep going with training, recovery and the best wearables for CrossFit.

CrossFit nutrition questions

What diet does CrossFit recommend?

CrossFit’s Level 1 guide says to eat meat and vegetables, nuts and seeds, some fruit, little starch and no sugar, at levels that support exercise but not body fat, and it points to the Zone Diet for more precision. Hard-training athletes often need more carbohydrate than “little starch” suggests.

How much protein do CrossFit athletes need?

ACSM and its partners suggest about 1.2–2.0 g per kg of body weight a day for athletes, spread over meals, with 15–25 g after hard training. Most people can reach that with food; a shake just makes it easier.

Is creatine good for CrossFit?

For adults, creatine is one of the best-supported supplements for strength training and repeated hard efforts, and the IOC group lists it among those with good evidence. It may add a little body weight. It’s not recommended for athletes under 18.

Should I eat before a morning WOD?

Many athletes feel better with a small, easy snack like a banana or toast, especially before heavy or long sessions. Others train fine on an empty stomach for a short class. Try both in training and see which works for you.

Are pre-workout supplements safe?

It depends on what’s in them. Many contain a lot of caffeine, which isn’t right for teens, pregnant women or people with heart conditions. Choose third-party tested products, check the caffeine per serving, stay within the label and ask your doctor if unsure.