HIIT 4x4
#570,553 of 719,896 by ratings on Apple · #39,692 of 50,597 in Health & Fitness
First seen by this census 09/05/2026 — the store does not publish a creation date
Last updated 06/26/2026
Tracked since 09/05/2026
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Category: Health & Fitness
Description
HIIT 4x4 is an Apple Watch exercise monitoring app for High Intensity Interval Training (HIIT). The app sequences exercise between high and low intensity intervals. The intensity of the exercise is measured as a percentage of a person's Maximum Heart Rate (MHR).
The HIIT 4x4 intervals are as follows:
- 10 minutes warmup at 60% MHR
- 4 minutes high intensity at 90% MHR
- 3 minutes low intensity at 70% MHR
- repeat high-low intervals 4 times (4 high intensity intervals of 4 minutes each = 4x4).
HIIT 4x4 uses a speedometer type dial to display heart rate. When the arrow is in the green zone then your heart rate is within the interval target. If the heart rate later falls out of the target range, warning chimes are issued until back in range.
Each person's MHR is different, and changes with age. A commonly used formula for MHR is 220 - age in years. A more accurate number can be discovered by using a heart monitor during all out exercise and observing the highest heart rate achieved.
HIIT 4x4 stores your workout history using Apple Health.
HIIT 4x4 is based on the High Intensity Interval Training 4x4 program developed by the Norwegian University of Science and Technology's Cardiac Exercise Group.
Alternatives to HIIT 4x4
| Name | Ratings | Rating | |
|---|---|---|---|
Norwegian 4x4 HIIT - Myworkout
by Myworkout AS
|
19 | 4.7 | compare |
HIIT 4x4 Lite
by Eastridge Technology
|
2 | 5.0 | compare |
4x4 HIIT
by Valabijs SIA
|
— | — | compare |
Interval Timer □ HIIT Timer
by Float Tech, LLC
|
86,518 | 4.8 | compare |
Tabata Timer and HIIT Timer
by Anuj Seth
|
73,691 | 4.8 | compare |
HIIT | Down Dog
by Yoga Buddhi Co
|
48,354 | 4.9 | compare |
HIIT • Workouts & Timer
by Fast Builder Limited
|
31,080 | 4.8 | compare |
Tabata Pro HIIT Interval Timer
by SIMPLETOUCH LLC
|
17,645 | 4.9 | compare |
Intervals Pro: HIIT Timer
by Intervals, LLC
|
13,611 | 4.8 | compare |
Keelo - Strength HIIT Workouts
by Throwdown Labs, Inc.
|
5,973 | 4.8 | compare |
Growth
Change in ratings, scaled to each window from the real gap between crawls. A window needs a full period of history before it reports anything.
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History
Tracking since 09/05/2026. History accumulates as changes are observed — check back soon.