Summary
 After
a 5 week conditioning period on a recumbent
cycle, The High Intensity Interval Training (HIIT) group
perform sprints while the Endurance Training (ET) group performed
a more traditional aerobic protocol, throughout the remaining
15 weeks. Both groups progressed in intensity. At the conclusion
of the study, the HIIT group lost over 3 times as much subcutaneous
fat as the ET group despite expending less than half as many
calories. For every calorie expended during HIIT, there was
a nine fold loss of subcutaneous body fat, as compared to the
ET group.
Comparison
(20 week program, 17 subjects)
|
Mode (ergocycle) |
Endurance Training |
High Intensity Interval Training |
|
Duration (minutes) |
30 and increased to 45 |
30 |
|
Frequency |
4/wk and increased to 5/wk |
25 continuous sessions; half completed before week 5
Week 5-20: 19 long & 16 short interval sessions |
|
Intensity |
60% HRR and increased to 85% HRR |
70% HRR warmup
60% of max output in 10 seconds & 70% of max output in
90 seconds; increasing 5% every 3 weeks |
|
Energy Expended (MJ) |
120.4 ± 31.0 |
57.9 ± 14.4 |
|
Fat Loss (mm) |
4.5 |
13.9 |
HIIT Protocol
- High Intensity Interval Training (HIIT)
- 5 minute warm-up at 50% HRR
- Short-interval work
- Initially 10 and later 15 bouts
- 15 seconds increasing to 30 seconds
- Long-interval
- 4 to 5 bouts
- 60 seconds increasing to 90 seconds
- Bouts separated by recovery periods allowing heart rate to
return to 120 to 130 bpm
Dependant Variables
- Fat Loss measured in millimeters
- Difference of before and after sum of skin
fold measurements
- Sum of skin folds
- Triceps, Biceps, Calf, Subscapular, Suprailiac, Abdomen
Also 3-hydroxyacyl coenzyme A dehydrogenase (HADH) enzyme
activity, a marker of the activity of beta-oxidation, was significantly
greater after the HIIT program
Also see Short Sprint Interval
Training (SIT) Guidelines and Sample Programs.
Trembblay A, Simoneau JA, Bouchard C. (1994). Impact of
Exercise Intensity on Body Fatness and Skeletal Muscle Metablism,
Metabolism. 43(7): 814-818.
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