Endurance training better than resistance exercise for slowing aging process: study

Distance running could indicate favorable reproductive potential, according to a new study. (YanLev/Shutterstock.com)

New European research has found that endurance exercise such as running, swimming, and cycling may be better than resistance exercise at slowing down aging on a cellular level.

Led by researchers at Leipzig University, Germany, the new study looked at the effects of three types of exercise, endurance training, high intensity interval training and resistance training, which involves strength training using weights, on the way cells in the human body age.

The team recruited 266 young, healthy but previously inactive participants and randomly split them into four groups.

One group was required to complete six months of endurance training of continuous running, another six months of high intensity interval training, while the third did resistance training using machines. The fourth group made no lifestyle changes and acted as a control.

The researchers also analyzed the participants' telomere length and activity of the enzyme telomerase in white blood cells taken at the start and end of the study. Telomeres are the protective "caps" at the end of chromosomes which are found in all the cells in the body. They naturally get shorter as we age, every time our cells divide, however certain lifestyle factors appear to accelerate this process. When telomeres get too short it is believed that cells are no longer able to divide in order to repair the body -- a sign of aging. Telomerase is able to counteract this shortening process and can even add length to the telomeres.

The findings, published in the European Heart Journal on Wednesday, showed that in the endurance and high intensity training groups telomerase activity increased two- to three-fold and telomere length was increased significantly compared to the resistance and control groups.

The researchers suggest that these two types of exercise may affect levels of nitric oxide in the blood vessels, which contributes to the changes in the cells.

Although the small sample size is a limitation of the study, the researchers noted that it is the largest study to date to investigate the effects of different exercise on cellular aging in a randomized controlled way.

Co-author of the study, Dr. Christian Werner, also added that, "Our data support the European Society of Cardiology's current guideline recommendations that resistance exercise should be complementary to endurance training rather than a substitute."

However, strength training also brings benefits for health. A recent study carried out by St. George's University in Grenada, found that when it came to heart health, strength training appeared to be more effective at reducing the risk of heart disease than cardiovascular exercise such as walking or cycling.

Meanwhile a US study published earlier this month also found just 1 to 59 minutes of weightlifting per week, split over either one, two, or three sessions, was associated with a 40 to 70 percent reduced risk of experiencing a cardiovascular event.