Stim vs Non-Stim Pre-Workout (Which One Should You Take?)

As previously stated, caffeine is the most common stimulant in pre-workouts, and for a good reason.

1. Improves Energy and Focus

Caffeine enhances exercise aerobically and anaerobically by improving focus, energy, and endurance [2].

Stimulants like caffeine block the brain’s adenosine receptors, keeping the neurotransmitter adenosine levels low. High levels of adenosine are responsible for feeling sleepy, so blocking those receptors keeps you energized and alert.

Research shows that stimulants may improve reaction time and delay fatigue, which are necessary factors in enhancing exercise performance [3].

If stimulant intolerance does not play a role, these pre-workouts are great for boosting energy for workouts earlier in the day.

2. Helps Burn Fat

One meta-analysis shows caffeine intake for fat loss might promote weight, BMI, and body fat reduction [4].

Since stimulants give you an energy boost, they can also potentially allow for a high-intensity workout and increase the total caloric burn.

Green tea extract is often paired with caffeine in pre-workout supplements for its thermogenic properties and added fat-burning benefits [5].

Non-stim pre-workouts are not worthless just because they lack a stimulant. These pre-workouts simply work differently to enhance exercise performance, like increasing blood flow.

1. No Jitters or Crashes

The massive kick of energy from caffeine or other stimulants is great until you crash hard, leading to headaches, decreased alertness, mood changes, and fatigue [7].

Using a non-stim pre-workout eliminates the crash and jitteriness many users experience, detracting from their workout efforts.

2. Enhancing Blood Flow

Many non-stimulant pre-workouts focus on enhancing nitric oxide production and promoting vasodilation which will increase blood flow, delivering necessary oxygen and nutrients to hard-working muscles.

Increasing blood flow during exercise leads to better pumps, more energy (without the stimulants), and reducing fatigue [8].

Again, caffeine is the most common energy-boosting ingredient in stimulant pre-workouts. Let’s look closely at other stimulants you may find on the pre-workout label.

1. Guarana

Guarana comes from the seeds of a South American tree that researchers once thought the stimulant effects came from a chemical that was specific to that tree, but they learned that Guarana has a high concentration of caffeine, containing up to 3.6% to 5.8% caffeine by weight.

Coffee only has up to 2%.

2. Theobromine

Theobromine is a stimulant and bronchodilator found in chocolate.

The primary benefit of theobromine is its bronchodilator properties, which will increase lung capacity, making breathing easier during exercise [11].

Without the benefits of stimulants, you should look for the following ingredients in non-stimulant pre-workout formulas.

1. Creatine

Creatine offers a lot of value as a pre-workout ingredient.

Though there has long been a question about its safety, research shows it is not only safe but effective and popular as a pre-workout supplement.

Research shows creatine may [15]:

• Help muscle cells produce more energy.
• Promote muscle mass
• Improve high-intensity exercise performance
• Improve brain function
• Reduce fatigue

“Supplementing with creatine provides additional ATP energy, which improves high-intensity exercise performance.” -Rudy Mawer, MSc, CISSN.

2. Citrulline

Citrulline enhances nitric oxide production.  Nitric oxide is a vasodilator, allowing more oxygen and nutrients to get to the muscles.

More oxygen means better muscle pumps, lower blood pressure, and reduced muscle soreness, which boosts exercise performance [16].

3. Glycerol

Glycerol, like citrulline, can also promote muscle pumps but does so by flooding your muscles with water and is found to benefit both aerobic and anaerobic exercise [17].