Caffeine and L-Theanine

What's Caffeine?

In plain terms

Caffeine is a natural stimulant found in coffee, tea, and cacao.

How it works

It blocks adenosine, a brain chemical that promotes tiredness, which can increase alertness.

Common effects of caffeine include:

• Increased alertness
• Reduced perceived fatigue
• Improved reaction time
• Higher motivation during physical activity

What's L-Theanine?

In plain terms

L-theanine is a naturally occurring amino acid found primarily in green tea.

How it feels

It promotes relaxation without causing drowsiness and is associated with increased alpha brain wave activity (Nobre et al., 2008 ↗).

L-theanine is commonly associated with:

• Relaxation without sleepiness
• Support for focus and attention
• Reduced stress response during demanding situations

How Caffeine and L-Theanine Work Together

When combined, caffeine and L-theanine complement each other: caffeine increases alertness and energy, while L-theanine promotes calm focus. Research suggests the combination can improve attention and task performance more than caffeine alone (Giesbrecht et al., 2010 ↗).

In simple terms: caffeine = drive, L-theanine = control.

Effects on Endurance

For endurance activities like running, cycling, hiking, or triathlons, both physical fatigue and mental fatigue matter.

L-theanine has been studied for stress-related effects and may support relaxation during demanding conditions (Hidese et al., 2019 ↗).

This combination may support:

• Sustained alertness
• Mental steadiness
• Better tolerance of long efforts

Effects on Strength Training

In resistance training, caffeine is commonly used to support training intensity and focus. Some people also find higher doses feel overstimulating.

Studies of caffeine combined with L-theanine show improved attention and accuracy during demanding tasks, suggesting a more controlled form of stimulation (Giesbrecht et al., 2010 ↗).

For lifters, this can mean:

• Better focus between sets
• More consistent technique
• Less “wired” feeling

Effects on Mental Performance

Beyond workouts, caffeine and L-theanine are commonly used for focus-heavy tasks. Human trials suggest L-theanine can support attention and working memory performance (Baba et al., 2021 ↗).

This can be useful for:

• Studying
• Workdays
• Long meetings
• Mentally demanding tasks

Why Underdogs Energy Gummies

Underdogs Energy Gummies are formulated with 20 mg of caffeine per serving plus L-theanine to support a more balanced energy experience.

This approach is designed to:

• Support energy without feeling “amped”
• Promote focus without feeling jittery
• Work for both physical and mental performance

Key Takeaway

Caffeine supports alertness and reduces fatigue. L-theanine supports calm focus without sleepiness. Together, they may support physical performance and mental clarity while helping reduce the jittery side effects often associated with caffeine alone (Nobre et al., 2008 ↗; Giesbrecht et al., 2010 ↗; Hidese et al., 2019 ↗).