14 DAY TRIAL // Exercise not only makes us look younger, but it seems that - in case of healthy elder individuals - resistance training actually restores the muscle tissue's youth.
A recent approach led by Buck Institute faculty member Dr. Simon Melov and Dr. Mark Tarnopolsky of McMaster University Medical Center in Hamilton, Ontario, made a gene analysis (before and after) in tissue samples from 25 healthy older men and women who did resistance training for six months, twice weekly, for an hour.
Their results were compared to tissue samples from younger healthy men and women. The research focused on age-specific mitochondrial function, linked to cell burnings. Mitochondrial dysfunction has been linked to muscle loss and functional impairment, common symptoms in aging.
In the case of older adults, the researchers discovered a decline in mitochondrial function with the aging but exercise induced a remarkable reversal of the genetic activity back to patterns observed in the younger adults. Also, before training, the older adults displayed 59% less power than the younger adults.
After the six months training, their strength rose increased with about 50%, being just 38% weaker than the young adults.
"We were very surprised by the results of the study. We expected to see gene expressions that stayed fairly steady in the older adults. The fact that their 'genetic fingerprints' so dramatically reversed course gives credence to the value of exercise, not only as a means of improving health, but of reversing the aging process itself, which is an additional incentive to exercise as you get older." said Melov.
The younger subjects (20 to 35 with an average age of 26) and older (older than 65 with an average age of 70) followed the same diet and exercise and none took drugs or had conditions interfering with the mitochondrial function. Tissue samples came from the thigh muscle and strength test was made on knee flexion.
"The older participants, while generally active, had never participated in formal weight training" said Tarnopolsky, who directs the Neuromuscular and Neurometabolic Clinic at McMaster University.
"In a four month follow up after the study was complete, most of the older adults were no longer doing formal exercise in a gym, but most were doing resistance exercises at home, lifting soup cans or using elastic bands. They were still as strong, they still had the same muscle mass. This shows that it's never too late to start exercising." said Tarnopolsky.
The researchers will investigate if resistance training induces any genetic impact on other types of human tissues, like those encountered in organs and if endurance sports (running, cycling) influence the mitochondrial function and the aging process. The research could also lead to finding drugs for activating gene expressions and modulating the aging process.
"The vast majority of aging studies are done in worms, fruit flies and mice; this study was done in humans," said Melov.