- Sports scientists enrolled 60 male University of Zululand students who admitted to being inactive smokers.
- Three times a week, one group did 20 minutes of high-intensity interval training on an exercise bike, while the other did 40 minutes of continuous pedaling.
- Both groups improved their fitness after eight weeks, but the interval training group did better.
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This is the time of year when resolutions are often made about smoking and exercise, which means that the first research published by young sports scientists has arrived at the right time.
And if you are a male smoker who is not physically active between the ages of 18 and 30, and wondering how to fit in some sports that will have the greatest positive effect on health in the most possible time, Nduduzo Shandu from the University of Zululand says he has the answer.
After putting 40 students who fit that description through two eight-week exercise-bike regimens, Shandu said 20 minutes of high-intensity interval training was not only faster but more effective than twice the amount of continuous pedaling.
The group that completed three sessions a week that repeatedly ran for eight seconds and then rested for 12 seconds, improved their fitness, health-related quality of life and psychological well-being more than the group that did continuous aerobic exercise in the same number of sessions. .
In a paper published in the International Journal of Environmental Research and Public Health, Shandu and co-authors from Zululand and the University of Essex in the UK said: “Our research shows that high-intensity interval training can be beneficial in improving health and mental well-being, reducing the risk of early and the progression of diseases caused by smoking, and indirectly increases the life expectancy of smokers.
To some extent, they say, this is not surprising because previous research has shown that interval training can be adapted to different fitness levels, requires less time, is more interesting and enjoyable than continuous aerobic training and has more physiological benefits.
However, in their study, interval training also improved lung function more than continuous exercise. Even so, both types of exercise lead to an increase in the lungs of smokers, measured by the amount that can be exhaled and the speed of exhalation, and Shandu says that this is the most surprising finding.
Both groups also recorded significant improvements in recovery heart rate but improvements in training intervals were greater. A measure known as the level pressure product, which is the product of heart rate and systolic blood pressure, was also good in both groups. This is considered a good indicator of how much oxygen the heart needs to function optimally.
About one in three South Africans smoke, and Shandu says previous studies have found a third of students started smoking at university as part of a significant life transition.
So he decided to target smokers when he advertised at the KwaDlangezwa UZ campus in Empangeni and enlisted 60 volunteers, divided into three groups.
Only two students dropped out of the interval training group, while four dropped out of the continuous aerobic training group before the eight-week climb, and the control group – who has been ordered to remain sedentary for eight weeks – finished with only 14 members.
The training group completed 24 sessions on a stationary cycle ergometer in the UZ gym, starting with a five-minute warm-up and ending with a five-minute and 20-second cool-down of the calf, hamstring, quadriceps, gluteus, back, neck and shoulder muscles.
It was in the middle of a training session that changed. The interval training group performed up to 60 repetitions of a routine involving sprinting all out and then resting. Shandu said he increased the resistance of the ergometer for participants who completed two consecutive sessions. The session took a total of 33 minutes.
After warming up, the continuous aerobic exercise group spent 40 minutes cycling at 60 revolutions per minute and the resistance was modified to ensure an oxygen utilization of 60% to 75% of the body’s maximum capacity. Each session lasts 55 minutes.
“Findings suggest that high-intensity interval training should be the preferred form of exercise training among college-age smokers for more significant and healthier benefits,” Shandu said.
But he admits his study has limitations. “Early, [it] consists of a small, highly educated, homogeneous sample, which limits the generalisability of our results and the power to detect statistically significant differences.
“Second, the findings may not generalize to other age groups. However, [they] consistent with previous evidence on the relationship between exercise and health fitness, health-related quality of life and psychological measures.
“Exercise is an important component in reducing the risk of diseases caused by smoking and may increase life expectancy, which may be related to physiological and psychological benefits.”
