Inhaling

A year ago a lingering aftereffect of COVID (yes I was vaccinated and boosted) was a serious sapping of my energy. The illness itself in February 2022 had been relatively mild and over in a week. Afterward I felt fine when just standing or sitting but became extremely tired and utterly out of breath from walking no more than 100 paces. I expected this energy drainage to dissipate quickly but it didn’t. Despite my efforts to exercise, it lasted through the summer. Things slowly improved after that but didn’t get back to “normal” (which is to say immediately pre-COVID level) until after my second bout with COVID in January of this year. Unlike my first experience with the virus, this one hit me hard for a few weeks. Yet, weirdly, afterward my stamina and oxygenation snapped back to January 2022 levels. I have no explanation for why this happened, but was happy to feel normal again regardless.
 
Of course, normal at 70 is not what normal was at 50, much less 30 or 20. Assuming no change in physical activity, the Harvard Medical Center notes that after 40 strength can decline 1.5% per year. Yes one can combat – even reverse – this with additional exercise and training, but these weren’t necessary before 40. The Harvard site adds, “Fast-twitch muscle fibers shrink and die more rapidly than others, leading to a loss of muscle speed. In addition, the capacity for muscles to undergo repair also diminishes with age.” Charming. I had just assumed earth’s gravity was increasing.
 
Perhaps more important than strength per se, however, is stamina – or so it seems to me after last year. While, once again, I’m happy to have recovered the endurance I had in January of last year, I still sorely miss what I had in, say, 1978. This is largely related to VO2 max. This is the maximum rate (V) of oxygen (02) your body can utilize during exercise. A high VO2 max is what keeps one from tuckering out when shoveling, running, hiking, rowing, or whatever. As with strength, VO2 max declines with age holding all else equal. Our lungs simply get less efficient.
 
According to Healthline, “good” V02 max numbers are for men

Age  20–29  30–39  40–49   50–59   60–69 70–79
         45.4       44        42.4     39.2     35.5      32.3
and for women
         39.5       37.8    36.3      33         30          28.1
 
Nonetheless, again as with strength, one can counteract the decline to a significant degree with exercise. High-intensity training (HIIT) is the preferred method: exercise hard for a short amount of time, rest for a short period, and then repeat multiple times. A recuperative day following each HIIT day is also recommended. This is more effective at raising VO2 max than slow-and-steady break-free exercise, though of course both help.
 
By dumb luck (and by being too cheap to hire a landscaper) rather than by plan I follow a HIIT schedule in spring and summer. I have a lawn suited in parts to a mountain goat. The sloped areas must be cut by hand because a tractor would tip over. This slip-and-slide task was not easy for me in 1978 when this was my parents’ property. In 2023 it is arduous in a way to which level mowing doesn’t compare. Every two passes I need (not want, need) to stop and catch my breath. It takes a dozen passes. In back of the house above the retaining wall there is another similar slope. They should be enough to get me literally to breathe easier.

My front lawn

Beatenberg – Stamina