The bad science behind fitness watches

The idea that data from a fitness watch will somehow affect our health is outdated and erroneous. Fitness watches mainly measure two things: amount of exercise and calories burnt. Vigorous cardio exercise for 20 minutes or longer speeds up the metabolic rate by 15 times! Eight 30-second sprints at maximum effort, interspersed with 90 seconds slow jogging, done three times a week, boosts the release of human growth hormone by 400 per cent. That’ll burn your body-fat for 24 hours, (and strengthen heart muscles and lungs). A million steps are therefore next to useless for fat burn! Exercise does not clean arteries nor slow their calcification, (heart disease and stroke) as shown when in 1979 a 28-year-young competitive marathon runner in Hawaii died from blocked arteries. Arteries clog up from high homocysteine, high triglycerides and inflammation. These three main factors are easily addressed with nutrition, but sadly the answers are very different to what mainstream doctors and dieticians tell us. (At 81, my arteries are scanned as clean).
Counting one’s calorific intake for weight control is meaningless. It’s the carbohydrates that fatten. (Vander Sherman & Luciano, “Human Physiology”, Chapters 5 and 7)
Digested carbs first top-up muscle and liver glycogen – stored sugar. The rest is rapidly converted to body fat in the cells’ mitochondria via the Krebs cycle. Digested fat only slowly converts to usable energy molecules in the liver. Refined sugar and HFCS (high-fructose corn syrup) convert rapidly and directly to body fat in the liver. 
Then we have homeostasis mechanisms that slow or speed metabolic rate, MR, depending on what, when and how much is eaten. Another such mechanism, the thermogenic effect, is bone-structure dependent. A light-boned ectomorph can quaff half a gallon of heavily sugared, HFCS ice-cream and yet weigh the same next day, since they experience a rapid, inherent MR rise after such a meal. A heavy-boned endomorph gains fat on a slice of apple pie with their very low inherent MR rise.
Thomas Turk