Seiler 4×8
Four eight-minute efforts with two minutes easy. In Stephen Seiler's 2013 study this beat both 4 × 4 and 4 × 16 minutes for fitness gains. Run the fastest pace you can hold evenly through all four: a notch below 4×4 effort, hard but never a sprint.
- Time
- 55 min
- Main set
- 4 × 8:00 hard
- Good for
- Run, Treadmill, Bike
Warm-up4 × 8:00 hardCool-down
The session
- 10:00Warm-upEasy
- 4 ×
- 8:00WorkEven pace. Hold it for all fourHard
- 2:00RecoveryEasy. Breathe it back downEasy
- 5:00Cool-downEasy
How to pace it
Run the fastest pace you can hold evenly through all four: a notch below 4×4 effort, hard but never a sprint. The simplest check is the fourth interval. It should be as quick as the first.
Who it’s for
Runners and other endurance athletes with a solid base who want a longer hard session. In the study, recreational athletes who trained with 4 × 8 minutes improved more than those doing 4 × 4 or 4 × 16 minutes.
Running it as a group
Eight minutes is long enough for a group to string out. The two-minute recovery starts on the same second for everyone, so the group comes back together before every rep.
Source
Seiler S, et al. Adaptations to aerobic interval training: interactive effects of exercise intensity and total work duration. Scandinavian Journal of Medicine & Science in Sports, 2013; 23(1): 74–83.
Host the Seiler 4×8 in PacePack
Pick it from the program library, share the code, and every phone in the group runs it on the same second, with a voice calling every interval and its effort.
The program library is part of Pro, with a 7-day free trial on the yearly plan. On Free, host the same timing as a Quick session: 4 × 8:00 with 2:00 recovery, a 10:00 warm-up and a 5:00 cool-down, for up to three runners.
iPhone only for now. Android is coming soon.
