palindrome emordnilap's Library tagged cardio →  View Popular

In my opinion, the best question to ask has nothing to do with whether one should be doing high intensity or steady state exercise.  Rather, the best question, the one the most often goes unasked, is this one:

What type of cardio progression should I be using?

Progression? Yea, you  know, how you’re increasing the work you do from one cardio session to the next in order to ensure that you continue to improve your fitness and lose body fat.

• December 2006, Canadian researchers reported that just two weeks of interval training boosted women's ability to burn fat during exercise by 36%.

• In January 2007, a six-month study was published showing that adding aerobic exercise had no additional effect on body composition, over diet alone.

• In June of 2007, a twelve-month study was published which had the subjects doing six hours of aerobic exercise per week, training six days a week, for one year. The average weight loss was only three pounds for that one-year period.

• According to a British study, levels of Human Growth Hormone, which assists in building muscle and burning fat, skyrocketed 530% in subjects after just thirty seconds of sprinting as fast as they could on a stationary bike.

• Australian fitness researchers had eighteen women perform twenty minutes of interval training on a stationary bike — eight-seconds of sprinting followed by twelve seconds of recovery — throughout the workout, three days a week.

The women lost an average of five-and-a-half pounds over fifteen weeks, without dieting. Similar groups performing forty minutes of moderate cycling, three days a week, actually gained a pound of fat over the same period. Two of the heavier women who did intervals dropped eighteen pounds.

• In a side-by-side comparison, researchers at McMaster University in Ontario measured fitness gains in eight interval exercisers — using twenty to thirty minute cycling workouts that included four to six thirty-second sprints — against eight volunteers who pedaled at a lower intensity for 90 to 120 minutes.

After two weeks, the interval group was every bit as fit as those who worked out three to four times as long.

To equate this to exercise, we want high intensity exercise with rest
interspersed. We want a very large oxygen deficit. In a study by
Tremblay and colleagues, it was demonstrated that high intensity
exercise, specifically intermittent, supra-maximal exercise, is the most
optimal for fat loss. There were two groups—the long, slow distance
aerobic endurance group (LSD) that was on their program for 20 weeks and
the high intensity interval training (HIIT) group that was on a program
for 15 weeks. The amount of energy utilized (calories) by the LSD group
was DOUBLE that of the HIIT group. However, six skin fold measurements
demonstrated greater loss in the HIIT group than the LSD group. When
this was expressed on a per energy basis, the HIIT group’s reduction in
skin folds was nine times greater than the LSD group. That is what you
call more bang for your buck (Willey 2007).

The HIIT group created large post-exercise oxygen consumptions
(EPOC), which can take up to 48 hours for your body to fully recover
from. This is where fat loss occurs, not during the hours spent on the
treadmill. In another published study by R. Bahr and performed at the
Department of Physiology at the National Institute of Occupational
Health in Oslo, Norway, it was demonstrated that low intensity (defined
as 65 percent of maximum heart rate for less than one hour) led to a
total EPOC of only five calories. On the other hand, intensive exercise
where the heart rate was above 85 percent of the maximum, led to EPOC
values of up to 180 calories (Staley 2005).