Why high intensity interval training is perfect for hectic Hongkongers
If "I'm too busy" or "I've no time" have been your reasons for shirking exercise, here's the truth: they're really bad excuses.
Getting in shape - and staying that way - doesn't require long hours at the gym. These days, supported by evidence from a growing pile of scientific studies, short and sharp workouts are becoming increasingly popular. Research shows they can be as effective as longer workouts for weight loss and athletic performance.
High-intensity interval training, or HIIT, involves repeated short bouts of vigorous exercises that push you to your limit, with only short rests in between each, explains Ray Loh, an exercise physiologist at Tan Tock Seng Hospital's Sports Medicine and Surgery Clinic in Singapore.
In a recent survey of 3,815 health and fitness industry professionals from around the world conducted by the American College of Sports Medicine, HIIT was identified as the top trend for next year. This is all the more remarkable considering it did not even make the top 20 in the previous seven editions of the annual survey.
Gyms in Hong Kong have been quick to hop on the trend. Flex Studio at Wong Chuk Hang will launch a new Sculpt and Burn class next week that's based on HIIT principles. Torq Cycle, a dedicated indoor cycling gym in Central, puts a spin on the typical spin class with a hybrid called TORQCore that combines 20 minutes of HIIT on the bike, 20 minutes of abdominal exercises and 10 minutes of stretching.
Loh says research has shown that the training improves aerobic capacity. It is also effective for burning fat, toning muscle, losing weight and for boosting your metabolic rate - meaning you will use more calories even when at rest.
"Your heart rate is maintained at a raised level even hours after the workout has ended. High-intensity exercise also causes more stress to the muscles, which, in turn, induces more repair and building to the muscles," says Loh. "HIIT is time efficient - it reduces the amount of time needed to get the same results."
There are many types of workouts, but in general they share basic principles: an intensity that is close to maximum, and bouts of work that range from five seconds to eight minutes. This can be applied to almost all sports, from running to cycling, stair-climbing, weightlifting and more.
Researchers from the Norwegian University of Science and Technology in May revealed their version of HIIT called "4x4 training": four minutes of work and three minutes of rest, repeated four times. In their study published in the journal PLOS ONE, after doing the workout three times a week for 10 weeks, the participants - overweight but otherwise healthy men - showed increased aerobic capacity and lower risk of heart disease.
Another workout involves seven minutes of high-intensity circuit training consisting of 12 body-weight exercises - such as squats, planks and lunges - each done for 30 seconds with 10 seconds rest in between. The circuit, designed by experts at the Human Performance Institute in Florida, is repeated two to three times.
Flex Studio's Sculpt and Burn class is based on the Tabata Protocol, a training method that was first tested on the Japanese Olympic speedskating team in the 1990s. The namesake of its creator Dr Izumi Tabata, the method takes just four minutes: 20 seconds of all-out effort, 10 seconds of rest, repeated eight times. "All-out" refers to an effort that is 170 per cent of your maximal oxygen uptake.
The last few repeats should feel "impossibly hard", according to Tabata.
In a small experiment conducted by Tabata, moderately trained students were split into two groups: one did an hour of steady cardio on a stationary bike five times a week, the other doing a 10-minute warm-up on the bike, followed by four minutes of Tabata intervals, four times a week. In addition the Tabata group also did one 30-minute session of steady exercise with two minutes of intervals.
After six weeks of testing, the Tabata group increased their anaerobic capacity by 28 per cent and maximal oxygen uptake by 15 per cent. The other group had a 10 per cent increase in maximal oxygen uptake but saw no changes to their anaerobic capacity.
"As the hectic pace of today's corporate world continues to infringe on the amount of time individuals have for exercise, these types of programmes can offer a good option to help busy individuals improve their health and recover from stress via exercise," say Human Performance Institute experts in their report in the May/June 2013 issue of the ACSM'sHealth & Fitness Journal.
There is a catch, however. If you're out of shape - be honest now - you'll need to first build a fitness base and learn good movement patterns before easing into HIIT progressively. As the ACSM states in their 2014 fitness trends report, many survey respondents warned about the potential dangers of HIIT, such as high injury rates.
"As the stress level of HIIT is very high, it might not be suitable for everyone," says Loh. "Beginners who are low in fitness level or muscular strength are not advised to start a HIIT programme as it will be less effective and increases the risk of injury.
"People who have been leading a sedentary lifestyle, those with chronic diseases such as diabetes, heart problems, respiratory problems, a family history of heart problems, and those who are injury-prone should consult a sports physician before starting any HIIT."
Loh also recommends doing HIIT only two to three times a week and on non-consecutive days because the body needs time to rest and recover.
Personal trainer Ian Tan was inspired to start his own HIIT gym called Ritual in Singapore earlier this year after dealing with busy clients. A workout consists of functional exercises (movements that mimic activities in daily life) using kettlebells, dumb-bells and suspension bands. You're done in 20 minutes - tops.
"In my opinion, it is the way of the future because people are only going to get busier and more stressed out," says Tan.
