With 3×10-second max-intensity sprints, and low-intensity warm-up and cooldown, REHIT Energizer works like this: 

• Warm up: 20-seconds to 2-minute 
• Sprint 1: 10-seconds 
• Recovery: 1-minute to 3-minutes 
• Sprint 2: 10-seconds 
• Recovery: 1-minute to 3-minutes 
• Sprint 3: 10-seconds 
• Cooldown: 3-minutes 

This workout might be a great choice for you if 2×15-second sprints feel too tough and 2×10-second sprints not challenging enough. 

The duration of this REHIT Energizer workout is 5:50 – 11:30 minutes, depending on the length of your warm up and recovery.