Can I do the Cooper test on a treadmill?

Yes, but performance is typically 5–10% better on a treadmill than on a track due to belt-assist and pacing. For meaningful longitudinal comparison, always use the same surface.

Why is twelve minutes a common workout length?

Long enough to drive adaptation (multiple VO2max efforts above 4 min), short enough to recover within a day. Many strength-and-conditioning programmes specify 10–15 minute conditioning blocks for this reason.

Does the timer work on a laptop with the lid closed?

No — when the lid closes the system sleeps and JS execution halts. Keep the lid open, or run the timer on a phone.

Can I cast the LED to a TV?

Yes via Chromecast/AirPlay tab-mirroring. The LED scales to fit the screen.

12분 타이머 · 무료 온라인 카운트다운

12분 타이머는 어디에 쓰나요?

Cooper 12-minute run test

Kenneth Cooper's 1968 12-minute field test is one of the most widely used aerobic fitness benchmarks in sport science. Run as far as you can in twelve minutes; divide distance by age and sex norms for a VO2max estimate. The protocol depends on knowing the exact moment to stop — this timer with a loud bell is the canonical execution.

Strong HIIT blocks

Three Tabata blocks back to back, or a longer single AMRAP (as many rounds as possible), or a paced EMOM. Twelve minutes is long enough to drive real cardiovascular adaptations and short enough to recover from the same day. Use the LED as a wall clock and run intervals against it freehand.

Roast vegetable batch reheat

A sheet pan of pre-roasted vegetables — broccoli, cauliflower, carrots, peppers — needs about twelve minutes at 200 °C to reheat through without going soft. Twelve minutes is also the rough window for a small batch of cookies (8–12) on a single sheet.

이 타이머 사용법

Click Start 12-Minute Timer above. The countdown opens at 12:00 and begins immediately.
자리를 비워도 됩니다. 선명한 빨간색 7 세그먼트 LED는 방 건너편에서도 보이며, 탭을 활성 상태로 둘 필요가 없습니다.
탭 전환은 자유롭게 하세요. performance.now()로 절대 종료 시각을 기준으로 계산하므로 백그라운드 스로틀링이 타이머를 느리게 하지 않습니다.
0이 되면 3음 차임이 울리고, LED가 깜빡이며, 탭 파비콘이 빨갛게 변해 한 번에 완료를 확인할 수 있습니다.
스페이스 키(또는 Reset 탭)로 다시 실행. 1〜8로 다른 프리셋으로 이동할 수 있습니다.

자주 묻는 질문

Can I do the Cooper test on a treadmill?: Yes, but performance is typically 5–10% better on a treadmill than on a track due to belt-assist and pacing. For meaningful longitudinal comparison, always use the same surface.
Why is twelve minutes a common workout length?: Long enough to drive adaptation (multiple VO2max efforts above 4 min), short enough to recover within a day. Many strength-and-conditioning programmes specify 10–15 minute conditioning blocks for this reason.
Does the timer work on a laptop with the lid closed?: No — when the lid closes the system sleeps and JS execution halts. Keep the lid open, or run the timer on a phone.
Can I cast the LED to a TV?: Yes via Chromecast/AirPlay tab-mirroring. The LED scales to fit the screen.

12분 타이머