What is intra-workout?”

It’s a question many weightlifters ponder as they search for the best tools to optimize their training.

Some say intra-workout supplements are indispensable for keeping your energy levels topped off during training. Many also believe they prevent your body from breaking down muscle while working out, boosting muscle growth over time. 

Others disagree, claiming intra-workout drinks are little more than sugary water that’s useless if you eat a half-sensible diet and follow a decent strength training program.

Who’s right?

Are intra-workout carb drinks the key to enhancing high-intensity exercise performance and muscle growth?

And if so, what’s the best intra-workout?

Get evidence-based answers in this article. 

What Is Intra-Workout?

An “intra-workout” is a dietary supplement consumed during a workout. 

Unlike pre-workout supplements that ready the body for training or post-workouts that aid recovery, intra-workouts focus on boosting exercise performance during a workout.

Ingredients in intra-workout supplements vary by manufacturer. 

While some contain vitamins, minerals, and other performance-enhancing compounds (e.g., betaine, beta-alanine, and citrulline malate), the most common ingredients are carbohydrates, like cluster dextrin or highly branched cyclic dextrin and essential amino acids (EAAs)

According to supplement manufacturers, the benefits of intra-workout supplements are that they boost exercise performance by helping you maintain higher energy levels during workouts and prevent muscle breakdown, improving muscle tissue growth over time. 

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Should You Take Intra-Workout Supplements?

For endurance athletes, the advantages of intra-workout supplements are clear.

But do intra-workout carbs and amino acids have a similar effect on weightlifters?

Here’s what science says. 

Intra-Workout Carbs and Performance

During high-intensity workouts, our muscles use carbohydrates stored in our muscles (glycogen) for energy.

A typical weightlifting session containing around 9 sets per major muscle group can deplete glycogen stores by up to ~40%. 

In workouts containing more sets, glycogen likely diminishes further, suggesting that intra-workout carbs could offer an advantage by preserving or restoring glycogen stores during long training sessions.

Some evidence supports this notion.

In a study published in The Journal of Strength and Conditioning Research, weightlifters did two grueling squat workouts in one day. During and after the first workout, half the weightlifters consumed a drink containing carbs, while the other half took a placebo

Those who consumed the carbohydrate sports drink significantly outperformed the placebo group in their second workout, completing more sets (~19 vs. ~11) and reps (~199 vs. ~132) and training for longer (~78 minutes vs. ~46 minutes).

These findings seem like a clear win for intra-workout carbohydrates. There’s a problem, though: Few weightlifters do “two-a-days” or perform back-to-back sets of squats to failure. As such, these results probably don’t apply to the average gym-goer. 

To complicate matters further, research is far from unanimous. When we look at studies involving more “typical” weightlifting workouts, most show that consuming intra-workout carbs has little effect on performance. 

Another area offering insights into how intra-workout carbs affect performance is research on endurance athletes.

Two meta-analyses suggest that unless you’re training on an empty stomach or your workouts exceed 70-to-90 minutes, consuming carbs just before or during endurance exercise offers no advantage.

With the above in mind, here are some reasonable guidelines about whether intra-workout carbs are necessary:

  • If you train fasted, do high-intensity, high-volume training, and work out for more than 70 minutes, downing an intra-workout drink containing 30-to-60 grams of carbs per hour of training will likely boost your exercise performance.
  • If you eat a mixed pre-workout meal within 2 hours before training, do moderate volume at a moderate intensity, and train for less than 70 minutes, you probably won’t benefit from an intra-workout supplement.
  • If you land somewhere between these scenarios, listen to your body. If you feel your strength fading after your first few sets, consuming intra-workout carbs may make you feel and perform better.


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Intra-Workout Amino Acids and Performance

The theory behind taking intra-workout amino acids is simple: Amino acids are the building blocks of muscle tissue. Consuming them during your workout ensures you have ample available, which should minimize muscle protein breakdown and, thus, aid muscle growth.

Having bigger muscles is a boon for performance because, generally speaking, the bigger your muscles are, the stronger you’ll be—a fact that’s especially true for advanced weightlifters. 

Some research supports this theory. 

For example, a study conducted at Charles Sturt University found that men who consumed an intra-workout drink containing carbohydrates and essential amino acids had lower muscle protein breakdown rates during and after training than those who took a placebo.

However, most research leans the opposite way.

A study published in the European Journal of Applied Physiology found that people who trained without eating breakfast had higher levels of muscle growth markers than their “fed” counterparts.

(This isn’t “proof” training fasted boosts muscle growth. Rather, it’s evidence that occasionally skipping breakfast prior to your workout won’t hurt muscle growth.)

Additionally, several reviews and meta-analyses indicate that when you consume amino acids matters little when it comes to building muscle. What’s more crucial is that you eat enough daily

Also noteworthy is that circulating amino acid levels don’t peak until about an hour after ingestion. 

In other words, any amino acids you consume during training most likely won’t be of benefit until after you finish. To raise amino acid levels during your session, you’d need to consume them beforehand.

In the final analysis, intra-workout amino acids probably aren’t necessary. 

Even when you haven’t eaten foods containing amino acids for several hours before training, the body is adept at preventing muscle breakdown. And if you’ve eaten protein within a few hours of training, you’re engaging in intra-workout nutrition whether you like it or not, given protein’s digestion rate.

More crucial than intra-workout amino acids is ensuring you get enough daily protein—about 1 gram per pound of body weight for most people.

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What’s the Best Intra-Workout?

If you typically eat a few hours before exercising and follow an efficient, well-structured training program, intra-workout nutrition likely isn’t a pressing concern.

However, some feel that sipping an intra-workout drink helps them train harder. If you’re among them, there’s no harm in continuing.

There’s no need to invest in specialized intra-workout supplements. Simply opt for a sports drink with 6-to-8% carbohydrate content, like Gatorade, Powerade, or BODYARMOR. They offer the necessary carbs without the hefty price tag associated with dedicated supplements.

(If you’d like specific advice about what supplements you should take to reach your health and fitness goals, take the Legion Supplement Finder Quiz. In less than a minute, you’ll know exactly what supplements are right for you. Click here to check it out.)

+ Scientific References