RIO DE JANEIRO — It’s not the size of your biceps that matters, it’s how use them, at least when it comes to adding years to your lifespan. A study by an international team of scientists found that weightlifting can prolong life when one focuses on improving muscle power, as opposed to muscle strength.
“Rising from a chair in old age and kicking a ball depend more on muscle power than muscle strength, yet most weight bearing exercise focuses on the latter,” explains study author Claudio Gil Araújo, professor and director of research and education at the Exercise Medicine Clinic – CLINIMEX in Rio, in a statement. “Our study shows for the first time that people with more muscle power tend to live longer.”
Muscle power, explains the research team, depends on one’s ability to generating force and velocity when it comes to movement. In mathematical terms, power is the measure of work performed per time unit (force times distance). When the same amount of work is completed in a shorter period, or when more work is performed during the same time period, power is increasing. Climbing stairs requires power because the faster you climb, the more power you need. Strength, on the other hand, doesn’t take time into account.
“Power training is carried out by finding the best combination of speed and weight being lifted or moved. For strength training at the gym most people just think about the amount of weight being lifted and the number of repetitions without paying attention to the speed of execution,” says Araújo. “But for optimal power training results, you should go beyond typical strength training and add speed to your weight lifts.”
Araújo and his team recruited 3,878 non-athletes (68% were men) between 41 and 85 years of age to take part in a maximal power test between 2001 and 2016. The age group was chosen because muscle power gradually decreases after age 40. Using an upright row exercise, participants had their highest value recorded after three attempts with increasing loads. These values were then divided into quartiles for survival analysis, and analyzed separately by sex: 2.5 watts/kg was found to be the median power value for men, compared to 1.4 watts/kg for women.
After a follow-up with participants approximately seven years later, the authors found that 10% of men and 6% of women had died. Those with muscle power above their respective median were found to have the best odds for survival, whereas participants below the median had a significantly higher risk of dying. People who fell in the 26th to 49th percentile were up to 5 times more likely to suffer an early death, while those in the lowest quartile were between 10 and 13 times more likely to die.
Araújo says an upright row exercise was used instead of a handgrip device, which is often used to assess strength and power, because the motion is commonly used for things such as lifting groceries or even grandchildren. Now he’s calling on health care providers to emphasize the importance of muscle power when meeting with patients.
“We now show that power is strongly related to all-cause mortality. But the good news is that you only need to be above the median for your sex to have the best survival, with no further benefit in becoming even more powerful,” he says. “Doctors should consider measuring muscle power in their patients and advise more power training.”
The researchers presented their findings at EuroPrevent 2019, the official congress of the European Society of Cardiology.