Pre-workout is a product category that’s increased in popularity over the last few years, and many consumers are curious about how long the stimulatory effects last.

In this article we’ll provide an answer to that question based on medical research and a review of some of the most popular stimulatory chemicals in pre-workouts.

Chemical Review

Because very few supplement companies publish medical research of their products, the best way to determine how long a pre-workout will last is to analyze some of the most common ingredients individually. 

To estimate how long a pre-workout will last it’s important to understand a scientific term called “half-life”, which refers to how long it takes for the body to process 50% (half) of an ingested chemical compound. This will vary between people and this figure is given as an average based on medical research.

If we know the half-life, we can assume that much of the subjective feeling of the drug will have worn off by that point.

Caffeine is the most popular ingredient in pre-workouts, and one of the safest and most well-known stimulant compounds. As most consumers are aware, it’s the active ingredient in coffee. 

The half-life of caffeine is 5 hours based on medical research. For smaller caffeine doses such as 100 milligrams (mg), it’s likely that the effects will have worn off before then. But if your pre-workout contains larger doses like 300 or 400 mg, you may still be feeling the effects at the half-life point.

Guarana is another popular stimulatory ingredient found in pre-workouts and energy drinks. It’s a plant that contains caffeine, theobromine and theophylline, all of which are stimulant compounds.

The half life of guarana should be considered to be longer than caffeine, based on medical research, although the research on the topic is still early. 6 hours is a safe assumption.

Theacrine is a stimulant that’s becoming more common in pre-workout formulations because it’s proven to improve both energy and mood in medical studies.

This compound is more novel with less research behind it. The half-life is estimated to be about 20 hours, but anecdotal user reports have reported the effects being insignificant after 6 hours.

How Long Does Pre-Workout Last?

Based on the above research, we can say that the stimulatory effects of pre-workout are likely to peak around one hour after ingestion and may last up to 6 hours, but the effect will fade over time. 

Since the effects vary so much person-to-person, we recommend that consumers taking pre-workout use a smaller amount as a test to start out, and titrate up until they reach the full serving size.

Why Don’t We Recommend Pre-Workout?

We haven’t yet come across a pre-workout powder that we recommend, because they’re so often filled with added sugars and other questionable ingredients like artificial food dye.

Products like G-fuel are essentially overpriced caffeine water with artificial flavorings added.

Since caffeine is the most well-studied and effective performance enhancer, we recommend plain black coffee as a pre-workout. It has additional health benefits outside of the performance benefits, and is much cheaper than powdered pre-workout.

For consumers with a sweet tooth, using a natural sweetener like manuka honey or blackstrap molasses can add significant nutrients and healthy sugars.

Black tea is another great pre-workout option, containing around 60 milligrams (mg) of caffeine. This is a bit more than half that in a single cup of coffee.

Conclusion

It’s very hard to say how long pre-workout lasts on average, because the effects vary so much between people. A 105-pound woman with a slow metabolism will experience significantly different effects of the same pre-workout dose compared with a 250-pound man with a fast metabolism.

That being said, we can estimate based on medical research that the effects of a small dose of pre-workout are likely to last around 3-4 hours, while a larger dose (for example a caffeine dose of 350 mg) are likely to last up to the half-life of 6 hours and even slightly beyond.

The effects of pre-workout tend to peak around one hour post-ingestion depending on the stimulant(s) included, and the effects slowly fade after that point.

We recommend plain black coffee or coffee with natural sweeteners as a pre-workout, as it’s likely to be cheaper, healthier and just as effective (if not more) than typical pre-workout powders which contain potentially unsafe ingredients like artificial food dye and artificial sweeteners.