In The Nation on 17th June we read the article ‘How fit can you get?’ I’ll make two points. The author should have stated only that heartbeat can be lowered by vigorous or long exercise. However, by claiming that a lowered heart rate indicates heart health is incorrect.
A low heart rate is an indicator of the pumping action of the heart from a large stroke/volume, how much blood is pumped on each stroke, and strong contractility, the strength/speed of that pump. A young competitive marathon runner would have a resting pulse as low as 45 beats a minute, and yet in Hawaii in 1979 one such competitive marathon runner died of blocked arteries. However slow the resting heart rate.. clean arteries are needed for overall heart health. Clean arteries cannot be obtained from running or from tens of 1000s of daily paces.
Calories used during exercise cannot be accurately counted. Continuous vigorous exercise for at least 20 minutes raises one’s metabolic rate 15X.
Also, doing eight 30-second High Intensity Training sprints, HIT, (not more than 3X a week), to maximum effort/heart rate, (not to some recently invented theoretical zones), fat burn has been measured to continue for up to 72 hours due to the massive release of Human Growth Hormone and testosterone.
Consumed calories in food also don’t count as various homeostasis mechanisms exist that speed or slow metabolic rate, depending on what, when and how much or how little is eaten. One mechanism, thermic effect varies according to one’s bone structure. A light-boned person, an ectomorph, will burn off whatever is eaten, whether it be half a gallon of ice-cream or three loaves of vegan bread, and still weigh the same next day. They have a very high inherent metabolic rate rise after a meal. Conversely, a heavy-boned endomorph gains weigh on a slice of apple pie, and easily becomes obese from too much sugar, HFCS and carbs due to an inherent, very low metabolic rate rise.
Maybe in the distant future a wrist-worn gizmo will show, among other data, the calcification level in arteries, which today needs invasive surgery or a high-speed heart scan. Till then I’ll pass, and buy some juicy, fatty non-fattening,
high calorie steaks, with their fat full of artery-protective long chain fatty acids conjugated linoleic acid and Omega3;
and in the red meat, the easily assimilable and much needed iron and magnesium; all the essential amino acids and the B vitamins; always keeping in mind that if I BBQ those steaks, they’ll be forming pyrroles and acrylamides that inflame the colon, that give a high risk of colon cancer.