A new study challenges common assumptions about metabolism and aging. The research, led by Duke University associate professor Herman Pontzer and an international team of scientists, analyzed the daily calorie expenditure of almost 7,000 people of all ages in 29 countries using the “doubly labeled water” method, a urine test considered the gold standard for measuring energy expenditure. The study revealed several surprises:
- The study found that energy expenditures remain stable during the 20s, 30s, 40s, and 50s, which means human metabolism doesn’t start its decline as early as assumed.
- Metabolism does begin to slow down after age 60, with a gradual decrease of only 0.7% per year. So by the age of 80, a person should only see about 14% decline in metabolism than someone in midlife.
- Loss of muscle mass in old age contributes to the metabolism decline, as already shown through other studies, and these researchers also suggest that changes in cell activity play a significant role, as cells slow down over the lifespan.
- Strength training builds muscle mass and increases the metabolic rate because muscle is the active tissue, while fat just sits there as an energy storage tank.
- Endurance training (Xertion over a period of time vs. shorter Xplosive lifting like traditional training) increases the number of mitochondria and improves their health and function. Every mitochondrion Xpends energy to do its work, which increases your overall metabolism.
- Cardio training (intervals are best) also increases the number of mitochondria and improves their health and function.
All three of these slow the rate at which cells slow down through the aging process.
- Our Time Under Tension (TUT) aspect provides endurance.
- The Complete Muscle Fatigue (CMF) aspect provides strength.
- The interval nature of our workout creates heart rate spikes (when approaching CMF), which provides the cardio effect. And for those who want Xtreme cardio results, we have Xardio classes available to all members, whether group or 1:1!
Here’s an Xample of a man 70 years young, proving all the claims above: