What Are The Effects Of Pre-Workout? (Both Good & Bad)

For many of us, working out has become an activity we enjoy. Exercising promotes a healthy body, releases endorphins to help boost your mood and makes you stronger to make everyday life a little bit easier. However, with that said, working out is hard. If working out isn’t hard, you’re doing it wrong.

Part of the joy that comes from working out is the satisfaction and sense of accomplishment after a grueling leg day or hitting a new PR on bench, and if your energy levels are lacking, your workouts can suck. Before you reach for the coffee or soda, let’s talk about something that can really boost your energy levels for a killer workout: pre-workout supplements.

What Are Pre-Workout Supplements?

Well, as indicated by the name, pre-workouts are supplements you take before your workout. These supplements generally contain caffeine, sugars and amino acids that will enhance mental focus, give you a burst of energy and several of the pre-workouts on the market help you achieve a greater “pump” during your workout by acting as vasodilators.

Have you ever gotten a really good workout on a muscle and the muscle was completely saturated with blood and felt full and swollen? That’s the pump. A great pump is achieved by flooding your muscles with blood, which is expedited with vasodilators, or compounds that widen your blood vessels to allow more blood to pass through.

Another aspect of pre-workout supplements is fat burning, as they can induce an adrenaline surge that helps to burn fat while preserving muscle glycogen stores.

What Are They Made Out Of?

Pre-workouts are generally composed of a few parts: a strength booster, a stimulant, a muscle builder, a pump provider, a brain booster and a fat booster. Pre-workouts will have at least 2 of these components, if not all of them. Let’s break these down:

Strength Booster

Strength boosting ingredients like creatine or beta-alanine are almost always found in pre-workout supplements. These compounds cause muscles to contract faster when prompted. Since force equals mass times acceleration, an increased rate of muscle contraction helps your muscles produce more force. More force, means more weight on the bar, which translates to a bigger and stronger you!


If you’ve taken a middle school health class, you should be familiar with stimulants. Taurine and caffeine are the most popular ingredients to provide you with a boost of energy so you don’t get gassed as quickly in the gym. Have you ever thought that your muscles could take another set, but you just don’t have the energy to complete it? This is where stimulants jump in and give you a boost.

Muscle Builder

BCAAs and glutamine are the common ingredients for the muscle-building component of your pre-workout. It’s good for pre-workouts to have muscle builders so you don’t fatigue as quickly during your workout and the muscles already have some fuel to build themselves after your workout ends and before your post-workout supplement or meal.

Pump Provider

As we discussed earlier, the “pump” is the feeling of a muscle being full and saturated with blood. This is good because it lets you know the muscle was adequately exercised and the stretch you get in the muscle cells can lead to long-term growth. Arginine is the most popular pump provider in pre-workouts, with citrulline following closely behind.

Brain Booster

Ingredients like choline are often present in pre-workouts to give you increased mental focus. This can really help you zone in on your workout and crank out those reps with more control and confidence. Most of these ingredients are naturally occurring in the body.

Fat Burner

Pre-workouts can contain fat burning ingredients like green tea extract or synephrine to help your body increase lipolysis, or the breakdown of fats for use as energy. These are a great benefit of a pre-workout for someone looking to shed a few pounds and get a lean, ripped physique without sacrificing the protein your body needs to build muscle.

Side Effects of Pre-Workout Supplements

Pre-workouts have several amazing benefits like burning fat and giving you increased mental focus and strength; however, it is not without its downsides. Pre-workouts affect people differently, but have been known to have a few side effects.


One of the major side effects noted by users is “the shakes”. The shakes are caused by the stimulant effect being too strong on the user. Shaking hands and muscle spasms are characterized by this, and can make many people uncomfortable.


Another one of the side effects of pre-workout is headaches. Several pre-workout supplements contain vasodilators (the compounds that widen your blood vessels to give you more of a pump). This also widens the blood vessels in your head, which can cause headaches.

Loss of Sleep

Loss of sleep can also occur from the stimulant effects of pre-workouts if taken during the night-time. The caffeine and other stimulant compounds still present in your bloodstream could ruin a good night’s sleep for you if the dosage is too high.


Beta-alanine and vitamin B3 are present in several pre-workout supplements, and they can cause an unpleasant tingling sensation to people who are sensitive to these substances. The tingling has no harmful effects and isn’t an indicator of toxicity, but it can be weird to experience for the first time.


Last but not least, nausea can occur as a side effect from pre-workouts. This is simply due to the body not being used to the overload of nutrients.

Luckily, most of these side effects can be avoided by simply adjusting your dosage or diluting your mix with more water. Staying hydrated is extremely important when supplementing with a pre-workout, as it can have a mild diuretic effect.

Final Thoughts

Pre-workout is a great supplement, and can really boost your workout to the next level, especially on days where you’re dragging. Now that you’re aware of what goes into a pre-workout and how they could affect you, experiment with a few different ones and find one you like. Find the right dosage, stay hydrated and you’ll be seeing those gains in no time.

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