I’ve been meaning to review this study for some time now. A few years ago, a cardiologist at the University of Texas by the name of Dr. Ben Levine conducted a study that ought to be on the minds of anybody who is interested in living a longer and healthier life.
Dr. Levine and his colleagues put middle aged adults (around age 50) who were previously sedentary but otherwise healthy on an exercise protocol for two years, and performed various tests on their hearts before and after the study. They found that after two years, the subject’s hearts had effectively reverted back to those of a 30 year old’s. In other words, exercise made these people’s hearts age in reverse by almost twenty years.
The specific protocol that was followed by the subjects was not easy. It involved the following:
One session per week of a “Norwegian 4×4,” a type of workout that was pioneered by Norwegian cross country skiers. It involves doing an aerobic exercise (running, biking, skiing, take your pick) as hard as you can for four minutes, resting for three minutes, and repeating this four times. So for example, you might sprint for four minutes, walk for three minutes, and do that four times in a row for a total of 28 minutes.
One session per week of “maximal steady state exercise” for 30 minutes, such as a brisk jog or fast-paced bike ride.
One session per week of an hour of light cardio activity, for example a hike or an easy bike ride.
At least two sessions per week of strength training, such as weight lifting
Subjects also did some walking on non-workout days. In total, the subjects averaged 5-6 hours per week of exercise.
Before delving into specific takeaways that you might implement in your own life, I’d like to just give a quick overview of some of the strengths and limitations of this study:
This study was performed in sedentary but otherwise healthy (meaning no signs of existing heart disease, diabetes, etc) adults. It is an open question as to whether the results would apply just as well to unhealthy adults.
It’s also an open question as to whether the results would be quite so dramatic in somebody who is already fairly active – it’s reasonable to speculate that a 50 year old who is already playing tennis regularly or attending Crossfit classes might be starting from a much better place, and hence have less room to improve their cardiovascular fitness.
Prior research by Dr. Levine’s group found that a similar protocol applied to 70 year olds, while helpful for getting into better shape and health, did not have such profound benefits on the heart. So while exercise is good at any age, a key takeaway from this study is that it is important to start young if possible.
While the exercise protocol used in this study certainly worked wonders, that doesn’t mean that other exercise protocols might not be equally effective. We just can’t know, since a study comparing this protocol to other protocols hasn’t yet been done.
Finally, a key strength of the study: the subjects were compared to a control group of similar adults who were assigned to do yoga three times per week. So the fact that the exercise (“study”) group did so well is particularly impressive, because they weren’t being compared to other people who were told to stay sedentary, but rather to other people who were also getting (less intense) exercise.
With all of that said, the takeaway from the study is that for generalized health (as opposed to other specific goals, such as training to have the most muscle, or training to run a marathon), a good exercise program probably includes a mix of types of training and would include weekly bouts of:
At least one session of high intensity interval training, such as the “Norwegian 4×4” described above
At least one session of moderate intensity cardio training such as a jog
At least one session of prolonged (at least an hour) light cardio training such as a hike or leisurely bike ride
Strength training
Regular walking on non-exercise days
Intuitively, this makes a certain amount of sense, since each of the above types of training have been shown to bring certain specific benefits. If you can afford the time to follow Dr. Levine’s exercise protocol, it wouldn’t be a bad idea, since it is definitively proven to work. But even if you can’t, you might make it a point to try to copy the general idea behind it by incorporating each of the above types of exercise into your life as best you can.
Note too that the protocol is fairly agnostic on how you specifically choose to train. For example, you can do your cardio on a bike, on your feet, on an exercise machine such as a rower or elliptical, in a pool, or however else you choose. This is crucial, because it’s always best to do exercise that you enjoy and that can fit more conveniently into your life, otherwise you are not likely to stick with it long term. The key point is that an ideal exercise routine probably consists of low, moderate, and high intensity cardio training along with some strength work. It’s probable that any routine that checks all of these boxes will be beneficial.
