Question: I've seen sources where its discussed that the body gets use to the amount of caffeine that is being absorbed and does not create the effect desired.

Is it necessary to have a week of no / very low caffeine in take in order to get the desired effect back?

Answer: 
**1) Chronic caffeine intake can result in, at least partial, tolerance to caffeine effects.**

[Chronic ingestion of a low dose of caffeine induces tolerance to the performance benefits of caffeine (Journal of Sports Sciences, 2017)](https://www.ncbi.nlm.nih.gov/pubmed/27762662/):

> 
> Chronic ingestion of a low dose of caffeine develops tolerance in
>  low-caffeine consumers. Therefore, individuals with low-habitual
>  intakes should refrain from chronic caffeine supplementation to
>  maximise performance benefits from acute caffeine ingestion.
> 
> 
> 

[Time course of tolerance to the performance benefits of caffeine (PlosOne, 2019)](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6343867/):

> 
> In summary, the daily intake of caffeine (3 mg/kg/day) significantly
>  increased peak cycling power during a maximal incremental test for the
>  first 15 days of ingestion and improved VO2max for the first 4 days,
>  when compared to the same treatment with a placebo. Day-to-day
>  pre-exercise caffeine intake also produced higher peak cycling power
>  during the 15-s Wingate tests for ~18 days of intake, although Wingate
>  mean power was only increased on the first day of ingestion with
>  respect to the placebo.
> 
> 
> 

**2) Caffeine abstention may not have significant effects on physical performance.**

[Caffeine withdrawal and high-intensity endurance cycling performance (Journal of Sport Sciences, 2011)](https://www.ncbi.nlm.nih.gov/pubmed/21279864/):

> 
> A 3 mg/kg dose of caffeine significantly improves exercise performance
>  irrespective of whether a 4-day withdrawal period is imposed on
>  habitual caffeine users.
> 
> 
> 

[Effect of caffeine on metabolism, exercise endurance, and catecholamine responses after withdrawal (Journal of Applied Physiology, 1985)](https://www.ncbi.nlm.nih.gov/pubmed/9760346/):

> 
> Subjects responded to caffeine with increases in plasma epinephrine at
>  exhaustion and prolonged exercise time in all caffeine trials compared
>  with placebo, regardless of withdrawal from caffeine. It is concluded
>  that increased endurance is unrelated to hormonal or metabolic changes
>  and that it is not related to prior caffeine habituation in
>  recreational athletes.
> 
> 
>
The time in which you develop a tolerance, and the degree to which you can tolerate it, and the time in which in takes you to reset your tolerance all vary much from person to person.

When you feel like the amount you take daily is no longer affecting you, or not affecting you as much as it once did, you can take some time off. Maybe starting at a week, and then start taking it again and test if your tolerance has decreased or reset completely.

If you take a week off and you still don't feel much affect from the amount you normally take, take more time off, or ramp up your intake.

Essentially, just go off of the feel.