Pre-Workout Timing: When and How Much to Take
Taking your pre-workout 20 minutes too early (or late) can cut its effect by half. We break down the optimal caffeine window, beta-alanine loading, and how to avoid the crash.
The Caffeine Pharmacokinetics Window
Caffeine reaches peak plasma concentration 30–60 minutes after ingestion. Its half-life is 4–6 hours. Optimal intake: 30–45 minutes pre-workout. Taking it 10 minutes before means you hit your warm-up before peak effect; taking it 90 minutes before means the peak has passed before your hardest working sets. Dose: 3–6 mg/kg bodyweight. For an 80 kg athlete: 240–480 mg. Most commercial pre-workouts contain 150–300 mg — check the label, avoid stacking with coffee.
Nitric Oxide Boosters: Citrulline and Arginine
L-Citrulline (not arginine) is the superior NO precursor — it avoids first-pass hepatic metabolism and raises arginine levels more effectively. Dose: 6–8 g citrulline malate, taken 45–60 minutes pre-workout. Expect noticeable increases in pump, vascularity, and a 5–10% reduction in perceived exertion during high-rep sets. Arginine alone has poor bioavailability and is largely ineffective at typical supplement doses.
Avoiding the Crash
Post-workout energy crashes are caused by adenosine rebound and blood sugar drops. Mitigate by: (1) not exceeding 400 mg caffeine total, (2) eating a mixed carb-protein meal within 60 minutes post-workout, (3) staying hydrated — even 2% dehydration amplifies fatigue. Avoid pre-workouts taken within 6 hours of sleep: the adenosine suppression will delay sleep onset and devastate recovery quality regardless of subjective tiredness.
Tolerance and Cycling
Caffeine tolerance develops within 4–7 days of daily use. Adenosine receptor density upregulates, blunting the stimulatory effect. Cycle strategy: use pre-workout 4–5 days per week maximum, skip rest days and light sessions. Every 6–8 weeks, take a 5–7 day caffeine break. Sensitivity returns dramatically. During the break, L-theanine (200–400 mg) reduces withdrawal headaches and improves focus without the stimulant effect.
Written by
Sofia Brenner
Certified Strength & Conditioning Coach