As you know, I love any excuse to rave about the benefits of HIIT: high intensity interval training - which I've written about before.
It's one of my favourite forms of training, and I've now another reason to share with you why HIIT should be in your workout program.
MUSCLE GROWTH WITH HIIT
A recent study shows that subjects gained just under a kilogram of muscle mass (0.907kg) after 3 weeks of HIIT.
Interestingly too, growth hormone was found to be reduced by 64% in the last workouts in comparison to the first.
And after 1 week, it had dropped by 50%.
It's further evidence that growth hormone increases may not mean MORE muscle growth - which I've spoken about in some detail before.
But back to the study, and 19 recreationally active male subjects in their twenties firstly did one-week of HIIT, with researchers examining their baseline fitness, body fat, and lean body mass, as well as their growth hormone response. A dexa scan was used to determine this data.
The same tests were all done at the end of each week of HIIT training.
HOW THEY TRAINED
WEEK 1: 4 x 30 sec sprints (with as much intensity as they can muster) three times per week with 4 minutes of rest in between in each repetition.
WEEK 2: 5 repetitions
WEEK 3: 6 repetitions
The subjects performed their sprints on a cycle ergometer and during their 30 second all out period, cycled with 7.5% of their bodyweight.
They rested one day in between each training session.
THE RESULTS: HIIT FOR MUSCLE GROWTH
The lean mass in the legs increased by 3% - which is a lot!
Total lean body mass increased by 1%. Both of these figures are statistically significant.
Arms lean mass, total body fat, arms fat and legs fat did drop too but it was nothing to write home about.
Body fat however, was not what was assesed in this study.
And with no information on calorie intake, it's unfair to asses this study as an indicator of HIIT'S ability to induce fat loss.
In other good news, sprint power and over all intensity also increased significantly after the 3 weeks.
HIIT FOR LEAN MASS AND FITNESS
The results are pretty obvious - HIIT will help you grow lean muscle mass and increase fitness and power.
Combine it with some bodybuilding training and a good diet, and you'll be well on the way to your ideal body!
"Stay Fit, Stay Flexed!"
REFERENCES
(1) Ritsche, Kevin, et al. "Acute Exercise-Induced Growth Hormone is Attenuated in Response to Short-Term, High-Intensity Exercise Training." Journal of Exercise Physiology (2014).
Author
Dayne Hudson