Science says that high intensity interval training is not only safe for those of us in middle age and beyond; it’s just what we need. Some form of heightened intensity appears to be the best way to enhance fitness, rev up your metabolism, and turn back the clock.
Research conducted in Europe and elsewhere has found that high-intensity training improves aerobic fitness as well as lengthier gym sessions did. It’s also been shown to decrease insulin resistance, reducing the chance of contracting metabolic syndrome, which can put you at higher risk for diabetes or heart disease.
High intensity training involves short bursts of all-out effort interrupted by very short rest periods. You can do this in a variety of ways – running, walking, cycling, swimming, rowing – but it’s all about forcing yourself to do any of them with the intensity required for maximum effect. This type of training engages 80% of the muscles of the body, compared to up to 40% during moderate jogging or cycling. It engages not only leg muscles, but also the muscles in the upper body, such as the arms and shoulders.
A study from Denmark recently published in the British Medical Journal Online argues that the standard advice for people in middle age and beyond —to walk as much as possible or simply get moving in whatever way you can to avoid being sedentary — may be insufficient. The Danish team analyzed health and lifestyle reports for 10,000 adults over 10 years and found that regular, more-intense aerobic exercise, like fast walking or jogging, cut one’s risk factors for heart disease and stroke by as much as 50 percent, compared with people living a sedentary lifestyle. Casual daily walking, even for an hour each day, seemed to have little or no impact.
One of the earliest and most popular forms of high-intensity interval training, known as Tabata, was devised by Japanese physiologist Izumi Tabata, who was seeking to increase the aerobic fitness of his country’s Olympic speed skaters. This method involves 20 seconds of all-out effort followed by 10 seconds of rest, repeated 8 times to 20 times. This program incorporates elements of old-school calisthenics – burpees, squats, pushups, sit-ups and the up-and-back sprints. For some, the 20-second bursts can seem endless and the 10-second rests too short for recovery.
Is Shorter Better?
One of the most recent studies on high intensity training was undertaken by UK Doctor Michael Mosley, researcher for Eat, Fast and Live Longer, a series of TV specials created for the BBC and author of The Fast Diet, which has become a best-selling book. His approach to overhauling fitness is similar to his approach to eating – what’s the minimum amount of time or effort needed to get the benefits?”
His answer is just three minutes a week — if you have the right genetic makeup.
Drawing on research from both the United States and Europe, Mosley focused his attention on studies of high-intensity training with the question “would it benefit us a lot, a little, or none?”
Using an exercise bike for his testing, the method was fairly simple: a couple of minutes warming up at moderate speed, followed by 20 seconds of high intensity, which was as fast as he could go. He then repeated the cycle two more times for a total high-intensity workout of one minute. Following this routine three times a week, he recorded three minutes of high-intensity training.
A number of health indices were gathered from Mosley before he started, and after four weeks of training, he was retested. One of the main tests was for insulin sensitivity because his father had been a diabetic and had died from complications linked to the disease. Mosley’s insulin sensitivity was just barely within a healthy tolerance level before the training began and after the four weeks of training his insulin sensitivity improved by 24%. It is not clear how high intensity training affects insulin sensitivity; scientists suggest it could be because this type of training uses many more muscles than conventional aerobic training.
A similar study published in Medicine & Science in Sports & Exercise in 2011 found a 35% improvement in insulin sensitivity after only two weeks. This study used volunteers who had done no exercise for over a year, and only had to work at 60% peak power (80- 95% of heart rate reserve). Their biking regime was ten 60-second bursts of intense pedaling with 60 seconds of recovery time in between each, performed three times a week.
There are some things that high intensity training will not necessarily do for you. For example, in Mosley’s case, it did not improve his aerobic fitness – the other main health index tested before his four week study. The reason Mosley’s aerobic fitness did not improve was because of his genes. A genetic test taken before the study predicted that no matter how much exercise he did, his aerobic fitness was unlikely to improve to the same extent as someone whose genes resemble those of an Olympic gold medalist.
It’s an Individual Thing
Apparently, around 15% of the population falls into the category of non-responders (like Mosley), and around 20% are high-responders (gold medalists). That means the majority of us – some 65% – fall somewhere between these two extremes. Evidence shows that one of the best predictors of a healthy long life is the body’s ability to take in and use oxygen while we are exercising maximally. The more blood the heart pumps around the body, the more oxygen our muscles use and the lower our risk of disease and early death. Research shows that by looking at just 11 genes in a person’s genome, it can be determined where they will fit on the spectrum of non- to high-responders.
The variation in individual response to exercise allows no guarantee that following a particular regime will actually give us the right results. And, while technological advances in genome research may move us into an era of personalized medicine and perhaps personalized exercise, it is clear that the link between exercise and health is an individual thing. Until genome testing becomes available, methods like high intensity training can be useful in helping us determine what works for us, and it allows us to fine-tune an exercise program to fit more easily into our lifestyle.
THE TABATA ROUTINE
To follow the Tabata routine, pick an exercise and either set a timer for 20 seconds on and 10 seconds rest or watch the time as you move from high intensity to rest. Exercise as hard as you possibly can for 20 seconds and then rest for 10, repeating this routine 8-20 times total. If you’re not out of breath or seeing stars by the end, you’re not pushing hard enough. You can use the Tabata protocol with almost any exercise but here are a few to get you started.
Bikes are perfect for engaging your whole lower body but it’s a little easier to time and to rest on a stationary bike—you can just take your feet off the pedals for 10 seconds rather than trying to start and stop/coast on the road.
Similar to a traditional squat except that these require you continue down, dropping your butt towards your heels until your fingers touch the floor. Going through the full range of motion gets your heart rate up faster and engages more muscles. And, contrary to popular belief, researchers now say that for healthy people, squatting to the ground won’t hurt your knees.
With these lunges, add a jump in between alternating legs to up the difficulty and cardio factor. Start by stepping your right foot forward into a deep lunge, until your leg is parallel with the ground, then jump, bringing your back foot forward and landing in a lunge. You can step through each lunge if jumping gets too hard.
Take a jump rope and jump as fast as you can, using whichever foot pattern like. Make sure your rope is long enough before you start. To check for proper length, stand in the center of your rope and pull the handles straight up. They should come at least as high as your armpits.
THE MOSEY METHOD
Done on a standard exercise bike:
1) Warm up for a couple of minutes with some gentle cycling
2) Cycle as fast as you possibly can for 20 seconds
3) Cycle gently again for a couple of minutes to catch your breath
4) Do another 20 seconds at highest possible intensity
5) Then, for a final time, two minutes gentle cycling to catch your breath
6) Cycle full throttle for a final third period of 20 seconds.
Do this program three times a week for a total of 3 minutes a week of intensive pedaling and about 6 minutes of gentle pedaling.
THE 2011 METHOD
Done on a standard exercise bike:
1) Warm up for three minutes with some gentle cycling
2) Cycle as fast as you can for 60 seconds
3) Allow 60 seconds of recovery time by slowing or stopping
4) Repeat steps 2 and 3 ten times
5) Allow 5 minutes of gentle cycling for cool down
Do this method three times a week for a total of 30 minutes of intense pedaling and 60 minutes of gentle pedaling.