Exercise Dose

My last newsletter concentrated on exercise variety as a vital key to maintaining our health over the years. Compared to sitting at a desk, or sitting in a vehicle, or just sitting on the couch, any exercise is better than none. In my experience with patients who do get regular exercise, they usually have one particular activity that they do almost exclusively. I have the running folks, and the tennis players, and the cycling enthusiasts, and the weight lifters, and so on. Each of these activities is great, and each of the activities meets some of the needs of the body, but none of the activities meets all the needs of the body. The body is complex and has lots of needs. It needs balance, coordination, strength, speed, endurance, flexibility, environmental responsiveness, adaptability, and resilience. I touched on most of these in the last newsletter.

What I did not cover that is crucial is dose. How much exercise do we need? I stressed variety last time but did not comment on the number of minutes a week of these activities we need to increase our healthspan. Are the steps I take to get from the couch to the fridge enough to meet my health needs or do I need more? Fortunately, some new data on this very subject was highlighted in a recent Dr Mercola article which impressed me as important to share. Some of the results surprised me. The data showed the same J-curve Goldilocks zone for exercise that we have seen in just about every other process in the body. More is not better. There is a right amount, too little, and too much. The surprise to me was that too much exercise left folks worse off than doing no exercise at all.

The realm of exercise where too much is worse than none at all is the realm of vigorous exercise, specifically high aerobic exercise and high-weight training. The metrics researchers are looking at are things like all-cause mortality, incidence of atrial fibrillation, and development of atherosclerosis (hardening of the arteries). Mostly this research looked at folks over 40 years of age. The most impressive research looked at over a million people for 10 years. While you are young, your body is still resilient enough to not show the consequences that researchers can measure. Once you get over 40, measurable problems start showing up. With aerobic activities, ones where it is difficult to carry on a conversation while exercising, most of the benefit is gained in the first 20 minutes of the exercise. The maximum benefit seemed to top out at 75 minutes of this type of activity per week. More than that and the negative side effects start outweighing the benefits. For instance, looking at triathletes over age 40 showed a 500% to 800% increase in atrial fibrillation compared to moderately exercising people. Great benefits are gained in that first 20 minutes, but beyond that not so much. When I do HIIT (high-intensity interval training), I generally keep it to 15 minutes two or three times a week.

The numbers for weight training were even more surprising. The sweet spot for weight training appears to be 20 minutes two to three times a week, or 40 to 60 minutes a week. Doubling this amount actually negates the value of the training such that it is as though you have done no exercise at all. I have generally been doing 40 minutes of weight training twice a week with 10-16 minutes of elliptical workout. After reading this data, I shifted to 20 minutes of elliptical and only 30 minutes of weight training. It could be that I need to lower my weight time even more.

On the flip side, the data shows that we can not overdo moderate exercise. Gentler activities like walking are powerful at increasing our healthy lifespan. Every 1000 steps you take each day reduces your all-cause mortality by 10 to 15%. This benefit decreases at 6000 to 8000 steps and plateaus at about 12,000 steps. For most folks, 2000 steps is about one mile, and just 2 miles or 4000 steps will make a significant improvement in your lifespan. The other relevant factor is the speed of walking. A brisk pace of 3 to 4 miles per hour showed better results than the casual pace of 1-2 miles per hour. The pandemic may actually have increased many people’s health simply because folks were getting out and walking the neighborhood. I was seeing folks out walking their dogs all the time. That was new for my hood.

The last point that impressed me in the Mercola article was the analysis of the differing benefits of different exercises when engaged in the proper doses. Tennis and badminton ranked the highest while going to the gym ranked the lowest. These were not small differences. Tennis was 6 times as beneficial as gym workouts at reducing all-cause mortality. When the researchers tried to figure out why there was such a big difference between activities, what they saw was that the difference was not a physical issue but rather a social one. Exercise activities that were higher in positive social interaction were much better than solitary activities by a long shot. Exercise that is playful and encourages connection with others offers vastly greater benefits than just the exercise alone offers. We have seen this same finding in diet studies as well. Many tremendous results have been found with a particular diet by one researcher but not by other researchers trying to duplicate the results. The difference would lie in how the study was conducted, not in the particular diet being studied. The difference was in the level and kind of social interaction the study participants got because of the study design. The more positive social interaction there was, the better their health outcomes were.

So what does all this tell me? It says that the most important exercise you can possibly do to reduce all-cause mortality is to exercise the facial muscles that enable you to smile. Mix that exercise with participation with other people and you have ignited a powerful health and life extension force for yourself. Positive social interaction appears to be the most profound single thing you can do to improve your health and lifespan. Yeah, lifting weights and running around the neighborhood has its benefits, and I definitely recommend them, but they just do not undo the damage loneliness does to your health. So why not combine exercise with fun, playful activities? That was why tennis (or these days pickleball) ranked so highly on the impact on health. Besides, doing something fun that happens to involve moving your body is way easier and more motivating than practicing running for your 10^th marathon this year all by yourself could ever be. Give it a thought.

Take care,

David

Ellen 

While I was back east visiting my son and daughter-in-law, Ellen was at home with her sister. While the cats away the mice will play! They had a great time eating all sorts of things we don’t normally have around the house. They made up their own Thanksgiving dinner with all the fixings. Good times were had by all! Happy Holidays!