- Tabata: 20s work / 10s rest × 8 rounds (4 min total), original HIIT protocol, improves VO₂ max, requires 100% effort.
- 30/30: 30s work / 30s rest × 6 rounds, balanced and beginner-friendly with enough rest to maintain quality.
- 45/15: 45s work / 15s rest × 6 rounds, builds muscular endurance, harder due to less rest, for intermediate athletes.
- Custom: allows mixing work/rest/rounds to experiment and find the most challenging combination.