Coffee science

Caffeine, training and sleep

Last reviewed 7 Nov 2026

Performance+ is high in caffeine, so when you drink it matters as much as how much. This page sums up what research says about how long caffeine stays in your body, how it affects sleep, and how to time your cup around training.

How long caffeine lasts

Your body clears caffeine slowly. On average, half of it is still there 4–6 hours after you drink it, and in some adults it takes anywhere from 1.5 to 10 hours. So a 20 g Performance+ cup (about 386 mg) at 6 pm can still leave around 195 mg in your body at 11 pm, about as much as a full cup of regular coffee drunk at bedtime.

Sources: Journal of the International Society of Sports Nutrition, 2021 (opens in a new tab)

Caffeine and sleep

Caffeine can cut your sleep without you noticing. In a sleep study, 400 mg taken 6 hours before bed still reduced sleep by more than an hour, yet the participants' own sleep diaries didn't clearly show it. In a trial where people wore monitors, they slept about 36 minutes less on the days they were asked to drink coffee, and in a small lab study, caffeine 3 hours before bed pushed the body clock about 40 minutes later.

Some people are affected by less

Some people's sleep is affected by as little as one cup. Finland's food authority notes that around 85 mg for a 60 kg adult can disturb sleep (quoted in the Food Safety Commission of Japan's fact sheet).

Sources: Journal of Clinical Sleep Medicine, 2013 (opens in a new tab) · New England Journal of Medicine, 2023 (opens in a new tab) · Science Translational Medicine, 2015 (opens in a new tab) · Food Safety Commission of Japan, caffeine fact sheet, 2018 (opens in a new tab)

Timing your cup around training

In sports research, caffeine is most often taken about 60 minutes before exercise, in amounts of 3–6 mg per kg of body weight. Very high amounts (around 9 mg/kg) are linked with a high rate of side effects, so more is not better. Enter your weight in the calculator and it turns this into grams of coffee for you.

Sources: Journal of the International Society of Sports Nutrition, 2021 (opens in a new tab)

Calculator

If you train in the evening

Evening sessions are where timing matters most.

Make it smaller: an 8 g Performance+ cup (about 154 mg) at 6 pm leaves roughly 75 mg by 11 pm.
Switch to Lifestyle: a 15 g cup has about 145 mg, with a lighter, fruitier taste.
Set a cut-off: one sleep study suggests having larger amounts of caffeine before 5 pm at the latest, and at least 6 hours before bed. The bedtime checker shows the latest time for your cup.

Sources: Journal of Clinical Sleep Medicine, 2013 (opens in a new tab)

Bedtime checker

Why it differs between people

The same cup affects people differently. Your genes shape how fast your liver breaks caffeine down, and heavy caffeine use can speed it up. Pregnancy can make it last up to 16 hours, and the contraceptive pill also slows it down. If coffee tends to keep you awake, treat yourself as a slow clearer: use a smaller cup and an earlier cut-off.

Sources: Journal of the International Society of Sports Nutrition, 2021 (opens in a new tab) · EFSA Journal, 2015 (opens in a new tab)

Safety reference

Japan has no legal daily limit. Health Canada, the EU's EFSA and the US FDA use 400 mg a day as a reference for healthy adults. If you're pregnant or breastfeeding, or have a heart condition or anxiety, check with your doctor.

During pregnancy, EFSA's reference is 200 mg a day.

Sources: Health Canada (opens in a new tab) · EFSA Journal, 2015 (opens in a new tab) · US FDA (opens in a new tab)

Sources

Research changes. These summaries reflect the studies available on the date shown, and we update them as new evidence appears. They are general information, not medical advice.

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