CortexLit

CortexLit tool · Caffeine · Runs offline · No account

Caffeine and Sleep Trade Checker

Compare a week with pre-exercise caffeine against a week without, using your own session and sleep ratings.

← Back to the article · See the evidence

This tool gives general information based on the research summarised in Caffeine Before Exercise: What the Evidence Supports. It is not a medical device, does not diagnose, and does not replace advice from your clinician.

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Free (this page)
  • side-by-side week comparison
  • plain-language reading of the trade
  • text export and print
  • all citations and cautions


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  • calendar (.ics) logging reminders
  • unlimited share images
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Free tier: 1 share image per result.






Commercial disclosure: optional paid Plus tier; all evidence, cautions and the main result are free. No affiliate links, no sponsors.







What this is based on


Every output names at least one verified PubMed source. Identifiers were verified on 2026-10-11 in an earlier batch and carried over into this build; they were not re-queried here, and no retraction database was checked. Verification was at abstract level.


Marcus 2023
Marcus GM, Rosenthal DG, Nah G, et al. Acute Effects of Coffee Consumption on Health among Ambulatory Adults. N Engl J Med. 2023;388(12):1092-1100. doi:10.1056/NEJMoa2204737. PMID: 36947466.
PMID 36947466 · randomized controlled trial · weight 0.8 · abstract level
Drake 2013
Drake C, Roehrs T, Shambroom J, Roth T. Caffeine effects on sleep taken 0, 3, or 6 hours before going to bed. J Clin Sleep Med. 2013;9(11):1195-1200.
PMID 24235903 · randomized controlled trial · weight 0.8 · abstract level
McLellan 2016
McLellan TM, Caldwell JA, Lieberman HR. A review of caffeine's effects on cognitive, physical and occupational performance. Neurosci Biobehav Rev. 2016;71:294-312. doi:10.1016/j.neubiorev.2016.09.001. PMID: 27612937.
PMID 27612937 · narrative review · weight 0.2 · abstract level


Limits: A two-week self-comparison is an observation about you. Expectation, training load and life stress all move these ratings, and a randomised trial found the steps-versus-sleep trade in monitored adults rather than in self-report.







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Inputs stay in this page's memory. There is no telemetry, no analytics call and no network request. Saving is opt-in, local to this browser, deletable, and unencrypted.