How Long Does Pre-Workout Take to Kick In?

By: Jeremy Fox, CNC, CPTPublished: June 8, 2022

Lately, I’ve seen a lot of young guys taking pre-workout supplements in the locker room right before training. And I’ll admit, I’ve done it too.

But does that give you enough time to reap the benefits of your pre-workout? And how long does pre-workout take to kick in?

I’ll give you answers to those questions in this article so you can know exactly when to take your pre-workout for maximum results.

How Long Does Pre Workout Take To Kick In

What Is Pre-Workout?

Pre-workout is a multi-ingredient supplement designed to increase performance during exercise. You take this supplement before a resistance training workout, as the name suggests.

Many pre-workout supplements come as a powder that you mix with water and drink. However, there are some pre-workout products sold in liquid form.

What Does Pre-Workout Do?

Pre-workout increases performance during exercise by boosting energy, increasing blood flow to the muscles, and delaying fatigue. Supplements achieve these effects through a combination of stimulants and specific amino acids.

How Long Does Pre-Workout Take to Kick In?

You might feel some effects of pre-workout within minutes, such as increased focus and tingling skin. But it generally takes 30 minutes to 1 hour for most ingredients to kick in.

Also, the time at which your pre-workout peaks depends on the formulation and dosage. Some ingredients take longer than others to take effect. And the amount of each ingredient can influence how long it takes.

Next, I walk you through key ingredients in pre-workout and how long they take to kick in.

How Long It Takes Each Ingredient to Kick In

While formulations vary between brands, a few critical components are found in nearly all pre-workout supplements. These ingredients are caffeine, beta-alanine, and l-arginine or l-citrulline.

Some pre-workouts also contain creatine, but it’s not as standard as the other ingredients.

Active Ingredients in Pre-Workout

  • Caffeine

  • L-arginine (or l-citrulline)

  • Beta-alanine

  • Creatine

How Long Does Caffeine Take to Kick In?

Caffeine is a stimulant that works by inhibiting the degradation of intracellular cyclic AMP (cAMP) and delaying fatigue. In other words, it doesn’t create energy, it just makes you feel less tired.

Moreover, caffeine is helpful during a workout because it can improve your stamina1. In addition, studies suggest that caffeine increases your metabolic rate, promoting fat loss2.

The amount of caffeine in a pre-workout supplement can range from 100 to 300mg. By comparison, an average cup of coffee contains about 150mg of caffeine.

Coffee vs Pre-Workout: Which Is Better Before Exercise?

Studies suggest that caffeine peaks in your body 60-90 minutes after taking it3. Another study showed that taking caffeine 1 hour before resistance training had the most significant impact on physical performance4.

How Long Does Pre Workout Take To Kick In Caffeine

Figure 1. The effect of caffeine timing on physical performance for men and women. Values show the percentage increase in vertical jump height. Adapted from Harty et. al.

How Long Does It Take L-Arginine and L-Citrulline to Kick In?

L-arginine is an amino acid that relaxes blood vessels and allows more blood to pass through. This temporary increase in vascularity and muscle volume is called “the pump.”

How Long Does A Pump Last?

L-citrulline works similarly to arginine to dilate blood vessels. You may see either one of these amino acids in your pre-workout supplement, but usually not both.

With increased blood flow, more oxygen and nutrients get into the muscles. And that can enhance recovery and growth.

One study showed that the effect of l-arginine peaked after about 1 hour before declining. At the same time, l-citrulline peaked at about 2 hours with a slower decline5.

In practical terms, it would be best to take l-arginine about 30 minutes before working out. Or you could take l-citrulline up to an hour before your workout.  

How Long Does Pre Workout Take To Kick In Blood Flow

Figure 2. The time effect of l-arginine and l-citrulline on the cGMP blood flow signaling pathway. Adapted from Masahiko et. al.

How Long Does It Take Beta-Alanine to Kick In?

Beta-alanine delays fatigue by buffering the pH levels in the presence of lactic acid. This effect allows for more intense training sessions.

In fact, a meta-analysis showed that people supplementing with beta-alanine significantly increased their exercise capacity6. That is, the amount of time they could work before getting fatigued.

Unlike other amino acids, beta-alanine isn’t used directly. Instead, it enables your muscles to store more carnosine over time and that increases performance.

Studies show that taking 3.2 grams of beta-alanine per day resulted in a 40% increase in muscle carnosine levels after 4 weeks7. And the effect doesn’t happen in minutes or hours. So the timing of your pre-workout shake is not as critical for beta-alanine.

How Long Does Pre Workout Take To Kick In Blood Flow

Figure 3. The effect of beta-alanine on physical performance as a result of increased muscle carnosine content. Adapted from Artioli et. al.

How Long Does It Take Creatine to Kick In?

Creatine is another common ingredient found in pre-workout supplements because it’s a critical component of the ATP energy pathway you use during resistance training.

Your body uses the available ATP within seconds of intense exercise. Then, your muscles fail, and you can’t perform more reps. But after a few minutes, ATP regenerates, and you can complete another set.

Creatine supplies phosphate, which helps ATP regenerate faster. This cellular energy allows you to train harder and longer than you usually would8.

Like caffeine, creatine reaches peak concentration in your blood 90 minutes after taking it4. And it stays in your bloodstream for about 6 hours.

However, the timing of creatine intake may not matter because the effect is dependent on muscle creatine saturation and not creatine in the bloodstream. In other words, the daily creatine dosage is more important than when you take it.

When To Take Pre-Workout

Generally, the best time to take pre-workout is about 30 minutes before resistance training. That way the ingredients kick in, but the effects don’t wear off before your training is complete.

For training sessions lasting longer than 1 hour, you could take pre-workout immediately before exercising. You won’t feel the energy right away, but the effects will kick in later in your workout when you probably need them most.

When To Take Pre-Workout

DIY Pre-Workout Timing

As you can see, the challenge is the different times at which the active ingredients take effect and wear off. In addition, differences in dosages and ingredients make it hard to know when to take pre-workout.

One way around this problem is to buy the pre-workout ingredients separately and mix your own supplement. This may sound like a lot of work, but it’s super easy and saves you up to 70% compared to name-brand pre-workout supplements.

Click here for my top 5 homemade pre-workout recipes.

Homemade Pre-Workout

How Long Does Pre-Workout Last Before It Goes Bad?

Now you know how long pre-workout takes to kick in and when you should take it. But how long does pre-workout last before it expires?

You’ve probably wrestled with this question if you’ve ever found an old tub of pre-workout in the back of your pantry. But before you take a scoop, make sure you know how to tell if your pre-workout is bad!

Click here to find out if pre-workout goes bad and how to know if your pre-workout is safe to use.

With this information, you can optimize your workouts by taking your pre-workout at the right time. And make sure you check out these other articles to get answers to all your fitness questions!

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