These two came out last week and I thought I'd pop them up here for your interest. Incidentally I suspect that most of the benefits of HIIT could be attained more quickly and with less risk, through proper resistance training.....but that is a different issue.
Anyway, the studies:
The actual protocol was quite tough by the look of it:
High-intensity interval training and hypertension: maximizing the benefits of exercise?
Anyway, the studies:
Twelve weeks of HIIE resulted in significant reductions in total, abdominal, trunk, and visceral fat and significant increases in fat free mass and aerobic power.
The actual protocol was quite tough by the look of it:
Subjects in the exercise group completed supervised exercise (8 s sprint, 12 s recovery) continuously throughout each 20-min session. The HIIE workload was set at 80–90% of each subject’s heart rate (HR) peak at a cadence between 120 and 130 r.p.m and recovery was set at the same amount of resistance but at a cadence of 40 r.p.m. Subjects were instructed to keep their exercise intensity at a level necessary to produce a HR between 80–90% of HR peak. As subjects adapted to HIIE training, workload was increased so HR stayed at the appropriate 80–90% HR peak level. HIIE was coordinated with a prerecorded compact disc counting down each sprint in a 3-2-1 manner. Subjects performed a 5-min warm-up and cool-down on the bike prior to and after each exercise session. All training cycling data included continuous recording of HR and r.p.m, whereas rating of perceived exertion [13] (RPE) was assessed at 5-min intervals.
High-intensity interval training and hypertension: maximizing the benefits of exercise?
Essential arterial hypertension is the most common risk factor for cardiovascular morbidity and mortality. Regular exercise is a well-established intervention for the prevention and treatment of hypertension. Continuous moderate-intensity exercise training (CMT) that can be sustained for 30 min or more has been traditionally recommended for hypertension prevention and treatment. On the other hand, several studies have shown that high-intensity interval training (HIT), which consists of several bouts of high-intensity exercise (~85% to 95% of HR(MAX) and/or VO(2MAX) lasting 1 to 4 min interspersed with intervals of rest or active recovery, is superior to CMT for improving cardiorespiratory fitness, endothelial function and its markers, insulin sensitivity, markers of sympathetic activity and arterial stiffness in hypertensive and normotensive at high familial risk for hypertension subjects. This compelling evidence suggesting larger beneficial effects of HIT for several factors involved in the pathophysiology of hypertension raises the hypothesis that HIT may be more effective for preventing and controlling hypertension.
Comments
I've always wondered how the times used in these interval studies (like this one and Tabata's original work) should be translated when one is using a different mode of exercise, e.g. running, rowing, etc. Ant thoughts?
Also, while the 20 minute duration may seem pretty tough when one is thinking of the Tabata protocol (I don't think it's possible to keep up the prescribed pace doing 20s:10S Tabatas), when the work duration is sufficiently short (less than 10-12 seconds if I recall correctly) such that oxygen bound to myoglobin isn't depleted, the intensity can be kept up for much longer before one feels gassed. Now, it's been my experience when using these "ultra short high intensity interval" protocols that you feel it more in the muscles being worked than in the lungs. There were a few papers on this type of protocol a few years ago. I'll see if I can find them, but if you google "ultra short high intensity inter van training" you should find it.
2) Strength training is much safer, no rapid, uncontrolled movement...
What do you mean by running. Are you talking about short sprints or long, slow distance training?
Also, "less effectively" for what? Certainly training muscles to be effective as a sprinter, sprinting is not an ineffective protocol.
As far as the blanket statement that strength training is safer than running, I guess you don't incorporate Olympic lifts into your program. Quite sad.
http://jamessteeleii.blogspot.co.uk/2012/05/theres-no-such-thing-as-cardio.html
And from a personal perspective...
I know it to be true.
I ran a half marathon having never "trained" for it, except for my regular HIT workouts.
I did it without being winded and a respectable time of two hours.
Again congrats!
Marc