Caffeine and fatigue

Explores the relationship between caffeine consumption and fatigue, including how caffeine affects energy levels, sleep quality, and long-term performance. Learn how to optimize your caffeine intake to combat fatigue without undermining recovery and hormonal health.

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The essentials for caffeine and fatigue — then explore the latest posts below.

The science of caffeine free energy drinks: How to boost focus without the crash

The science of caffeine free energy drinks: How to boost focus without the crash

Dr. Jonathan Pierce, PhD avatar
Dr. Jonathan Pierce, PhD: Clinical Psychologist & Neuroscience Specialist
Jan 10, 2026 · 12 min read

Non-caffeinated energy boosters, including caffeine-free energy drinks, may help support focus without a “crash,” largely by addressing fundamentals that influence energy and performance, such as hydration, electrolyte balance, and nutrient cofactors involved in energy metabolism. This approach differs from caffeine, which can reduce perceived fatigue by blocking brain adenosine receptors while sleep pressure continues to ...

The science of supplements: Which vitamins actually fight male fatigue?

The science of supplements: Which vitamins actually fight male fatigue?

Dr. Susan Carter, MD avatar
Dr. Susan Carter, MD: Endocrinologist & Longevity Expert
Dec 18, 2025 · 12 min read

In men with low or marginal levels, repleting key energy cofactors can reduce fatigue by supporting mitochondrial ATP production and stabilizing testosterone-related energy pathways. These include B vitamins (especially B12, folate, and B6), vitamin D, and zinc. Here’s how to spot the signals, confirm them with the right labs, and target what’s actually limiting your ...

Why do energy drinks make me tired? The crash mechanics and the best cutoff before bed

Why do energy drinks make me tired? The crash mechanics and the best cutoff before bed

Dr. Susan Carter, MD avatar
Dr. Susan Carter, MD: Endocrinologist & Longevity Expert
Nov 21, 2025 · 14 min read

Energy drinks can make you tired because caffeine and sugar can create a short-lived spike followed by a “crash,” and caffeine can also disrupt sleep long after the can is empty. If you keep asking “why do energy drinks make me sleepy,” the answer is often a mix of brain chemistry, blood sugar swings, hydration, ...

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