HIIT Workout Planner
Design high-intensity interval training sessions with customisable work/rest ratios and rounds.
Formula
Cycles = (Active Time × 60) / (Work + Rest); Calories ≈ (Work Minutes × Cal/Min × 1.5) + (Rest Minutes × Cal/Min × 0.5) + EPOC
The HIIT formula calculates training volume from available time and interval structure. Calorie estimation accounts for higher burn during work intervals (1.5x base rate) and elevated but lower burn during rest (0.5x). EPOC (afterburn) adds 10-15% for the elevated metabolism post-workout. This works because interval training's metabolic demand comes from repeated stress-recovery cycles that maintain elevated heart rate and oxygen consumption throughout.
Worked Examples
Example 1: Beginner Fat Loss Protocol
Problem:New exerciser wants to lose fat with 20-minute workouts, 3x/week.
Solution:Protocol: 5min warm-up, 20s work/40s rest for 10 rounds, 5min cool-down. Exercises: jumping jacks, high knees, bodyweight squats. Progress to 30s/30s after 4 weeks.
Result:10 rounds | 200s work | ~180 calories + afterburn | 1:2 ratio
Example 2: Intermediate Conditioning
Problem:Intermediate athlete wants to improve cardiovascular endurance with 25-minute sessions.
Solution:Protocol: 5min warm-up, 40s work/20s rest for 12 rounds (Tabata-plus), 5min cool-down. Exercises: burpees, box jumps, kettlebell swings. Maintain Zone 4-5 throughout work intervals.
Result:12 rounds | 480s work | ~280 calories | 2:1 ratio | High intensity
Example 3: Advanced Athletic Performance
Problem:Athlete wants maximal conditioning in minimal time, 3-4x/week.
Solution:Protocol: 5min warm-up, 45s all-out/15s rest for 8 rounds, 4min active recovery, repeat. Exercises: assault bike sprints, rowing, sled pushes. Target 95% max HR during work.
Result:16 total rounds | 3:1 ratio | ~350 calories | Very high intensity
Frequently Asked Questions
What is HIIT?
High-Intensity Interval Training alternates between intense exercise bursts and rest periods. Work intervals are performed at 80-95% max heart rate. HIIT improves cardiovascular fitness and burns more calories than steady-state cardio in less time.
How long should a HIIT workout be?
Effective HIIT workouts are 15-30 minutes including warm-up and cool-down. The high intensity means longer isn't better—quality over quantity. Going beyond 30 minutes usually means intensity is too low.
How often should I do HIIT?
2-4 times per week maximum with rest days between. HIIT is demanding—overtraining leads to injury and burnout. Allow 48 hours recovery between sessions. Complement with strength training and light cardio.
What's EPOC/afterburn effect?
Excess Post-Exercise Oxygen Consumption (EPOC) is elevated calorie burn after intense exercise. HIIT can boost metabolism for 24-48 hours post-workout, burning an additional 6-15% calories beyond the workout itself.
Is HIIT better than steady cardio?
For time efficiency, yes. 20 minutes of HIIT can match 40+ minutes of steady cardio for calorie burn and cardiovascular benefit. But steady cardio is lower stress and appropriate for recovery days.
Can beginners do HIIT?
Yes, with modifications. Start with longer rest periods (1:2 ratio), lower-impact exercises, and shorter sessions. Progress gradually over 4-6 weeks. If you can't recover during rest intervals, reduce intensity.
What exercises work best for HIIT?
Compound movements using multiple muscle groups: burpees, jump squats, mountain climbers, kettlebell swings, sprints, battle ropes. Avoid exercises requiring complex technique when fatigued.
Should I do HIIT fasted?
Personal preference. Fasted HIIT may enhance fat oxidation but can reduce performance. Most people perform better with light fuel 1-2 hours before. Stay hydrated regardless.