Caffeine is a great way to get a morning boost. But when you have it every morning, it loses effectiveness. Research in PLoS One asked eleven participants to drink 3mg of caffeine for 20 consecutive days. Ingestion of caffeine worked to increase peak cycling performance power in incremental exercise for the first 15 days, and then the effect weakened. Additionally, Medical News Today noted it takes about 7 to 12 days for a body to adapt to regular energy drink consumption. Therefore, tolerance to energy drinks happens faster due to their large amount of caffeine.
Registered dietician Anika Christ told CNET, “Developing a caffeine tolerance essentially means that the stimulating effects of caffeine become less noticeable after an amount of time. This is because your body becomes less responsive to the effects.” How you develop caffeine tolerance comes down to the way caffeine works on your body.
As Healthline reported, caffeine blocks adenosine receptors in the brain, which play a role in sleep. Blocking them means fewer are playing around in your brain, so you have more room for chemicals like dopamine to keep you feeling awake. However, the more you consume caffeine, the more receptors your body produces, meaning caffeine is less effective.