WORKOUT TIMERS

HIIT timer

Set your work, rest and rounds once, and let the timer run the session

High-intensity interval training, or HIIT, alternates short bursts of hard effort with easier recovery. Across controlled trials it improved fitness at least as much as steady cardio, often in less time 1,2.

Popular HIIT formats
FormatWorkRestRounds
30/3030 s30 s10 to 20
40/2040 s20 s8 to 12
45/1545 s15 s8 to 12
Tabata20 s10 s8
4×4 34 min3 min4

How to set it up in Cero

  1. Create a new simple timer.
  2. Set high intensity, low intensity and sets to your format, such as 40, 20 and 10.
  3. Add a warm-up and a cool down.
  4. Choose a sound, a voice cue or vibration for each change, so you never need to look.
  5. Save the timer to run it again, or duplicate it to make a harder version.

Make every interval count

  • Follow your heart rate with Apple Watch or a Bluetooth monitor. Adaptive HR can extend your rest until you’re ready.
  • Put Gym Display on a TV or a bigger screen for a class.
  • Play your own music through the whole timer, or pick songs for each interval.
Free toolTry a HIIT timer nowSet work, rest and rounds in your browser, free.

Sources

  1. Milanović Z, Sporiš G, Weston M. Effectiveness of High-Intensity Interval Training (HIT) and Continuous Endurance Training for VO2max Improvements: A Systematic Review and Meta-Analysis of Controlled Trials. Sports Med. 2015;45(10):1469-1481. doi.org/10.1007/s40279-015-0365-0
  2. Gillen JB, Martin BJ, MacInnis MJ, et al. Twelve Weeks of Sprint Interval Training Improves Indices of Cardiometabolic Health Similar to Traditional Endurance Training despite a Five-Fold Lower Exercise Volume and Time Commitment. PLoS One. 2016;11(4):e0154075. doi.org/10.1371/journal.pone.0154075
  3. Helgerud J, Høydal K, Wang E, et al. Aerobic High-Intensity Intervals Improve VO2max More Than Moderate Training. Med Sci Sports Exerc. 2007;39(4):665-671. doi.org/10.1249/mss.0b013e3180304570
  4. Bull FC, Al-Ansari SS, Biddle S, et al. World Health Organization 2020 guidelines on physical activity and sedentary behaviour. Br J Sports Med. 2020;54(24):1451-1462. doi.org/10.1136/bjsports-2020-102955

YOUR NEXT SESSION STARTS HERE

Bring the effort.
We’ll keep the time.

Cero is free to download for iPhone, iPad and Apple Watch.

Download Cero
Cero’s simple timer on iPhone 18 Pro, with the green wave about half full during a high-intensity interval

Cero is a timer, not a medical device. If you’re new to hard exercise, are pregnant or have a health condition, check with your doctor first, and stop if you feel unwell.