I returned to McMaster University this Fall to join fellow graduates of the Phys Ed/Kinesiology program in a reunion of 50 years of Kin at Mac. It was great to tour the campus, see the buildings that have remained the same and visit the ones that are new. It was nice to reminisce about my time as a young student at a university that is continuing to make a name for itself in Canada as well as other parts of the world. Many programs at Mac are becoming well know for their research and development and the Kinesiology program is one of them. We toured several new labs where graduate students are involved in many different studies of exercise and it’s various effects on the body. Being in the fitness business, and writing this column, I have researched these topics often. I was surprised to learn however that McMaster Kin students are researching the effects of “HIIT” programs on cardiac rehabilitation patients.
“HIIT” or high intensity interval training is not my first choice of program for someone who has suffered a heart attack. The words “high intensity” scare me just as much as they do my post cardiac event client. Exercise is certainly recommended for people in this category but moderate intensity is the norm. When I looked into this, and other studies like it, I found that HIIT certainly was beneficial, after a short period of moderate intensity exercise on a regular basis. Although I wasn’t able to access much of the McMaster studies I did find information from a study done at the Mayo clinic. This study involved 120 cardiac rehabilitation patients who were of similar size, shape, age and had other similar illnesses and medications. They all participated in moderate intensity continuous exercise for just one week. After that initial short week, 90 participants chose to switch to HIIT and 30 continued with the moderate intensity activity. Both groups exercised three times a week for 12 weeks. All were supervised and monitored.
Those who chose the HIIT sessions did one minute of high intensity exercise, at a level that made speaking difficult, followed by 3-5 minutes of low level activity such as walking at a casual speed. This alternating level activity was repeated between four and eight times. The group who chose moderate level activity performed 30 continuous minutes of walking or cycling at a pace that was somewhat challenging but sustainable. McMaster studies found that people preferred the HIIT due to the fact that the intense work was shorter. The Mayo clinic study found that after 12 weeks, the HIIT participants had lost 4 more pounds of body fat, gained 1.5 pounds of lean muscle tissue and trimmed one inch more off the waistline, on average, when compared to the moderate intensity group.
The amount of body fat and where it is situated on the body affects one’s risk of heart disease. Excess body fat, especially around the mid-section increases the risk. Those in the HIIT group therefore reaped more benefits since they lost more body fat from that area and increased their muscle mass. The study concluded that HIIT was an effective and beneficial form of exercise for heart attack patients enrolled in early outpatient cardiac rehabilitation. The McMaster study also concluded HIIT to be beneficial and found patients preferred it as it took less time out of their schedules. HIIT is a great way to get fit, cardiac rehab or not!