Research showed that caffeine consumption increases fat oxidation rates and spares muscle glycogen. This led to the theories that A) caffeine is an effective fat loss supplement and B) caffeine is an ergogenic aid (performance enhancer) that increases your body’s ability to burn fat for energy.

Caffeine’s primary mechanism of action, however, is not metabolic. Rather, caffeine functions as a sympathetic nervous system stimulant, increasing adrenaline levels.(type of hormone), which alerts your brain to remain in active mode.

Caffeine can be performance enhancer when taken around 2 mg/kg goes till 4 to 5 mg/kg, But tolerance(mean it became ineffective for body) to caffeine builds up quickly and at low dosages. Using just 1 mg/kg to 3 mg/kg induce  complete tolerance within 4 weeks.

Can we increase its dose continuously to became it effective ?

Increasing it can cause worse side effects increase anxiety, decreases sleep, increase cortisol production  and more common withdrawal symptoms are headaches, fatigue, depression and symptoms are observed when you takes daily 2 or more cup of coffee.

Can we consume it ?

Now we can say caffeine has psychological benefits and consuming it is personal choice, Now taking around 80 -100 mg can increase your motivation and alertness in gym but doses close to 5 mg /kg can taken very occasionally for heavy powerlifting training  .