Delay caffeine intake for 90 to 120 minutes after waking, with a maximum dose of 1 to 3 mg per kilogram of body weight, to prevent an afternoon energy crash.

noli's read

The recommendation to delay caffeine is based on the hypothesis of allowing cortisol to fluctuate naturally and adenosine to dissipate upon waking (expert opinion). However, a large-scale scientific review published in the Journal of the International Society of Sports Nutrition (JISSN), which synthesized more than 200 studies, shows there is no evidence that a morning coffee causes an afternoon crash, nor that delaying it prevents one. The JISSN also notes that in regular consumers, the cortisol spike associated with coffee is significantly attenuated regardless. Furthermore, delaying intake too late into the morning could shift the elimination of caffeine and disrupt nighttime sleep. Conversely, the dosage of 1 to 3 mg/kg is validated by numerous randomized controlled trials (RCTs) for optimally boosting concentration and energy.

the sources

1. 1NIH Office of Dietary Supplements 2026
2. 2Manson JE et al. 2019
3. 3Bhatt DL et al. 2019
4. 4Khan SU, Lone AN, Khan MS, et al. 2021
5. 5Liao Y, Xie B, Zhang H, et al. 2019
6. 6hubermanprotocols.com (fan reference guide)