Endurance exercise such as swimming, running, cycling, and cross country skiing promotes better aging than resistance exercise involving strength training with weight, according to researchers at Leipzig University, Germany.
In a new study, featured in European Heart Journal, a team of researchers evaluated the effects of three forms of exercise including endurance training, resistance training, and high intensity interval training on cellular aging of the human body. They discovered that endurance and high intensity interval training reversed or slowed aging of the cells, while resistance training did not.
Human DNA is organized into chromosomes in all the body cells and the end of each chromosome consists a repetitive DNA sequence known as ‘telomere’ that protects the chromosome’s end from deteriorating. As human grows older, the telomeres tend to reduce in size, signifying a molecular mechanism for cell aging, eventually leading to cell death when the telomeres are no longer able to support the chromosomal DNA.
The telomere shortening process is controlled by various proteins, of which enzyme telomerase can prevent the process and even add length to the telomeres.
For the study, the researchers enrolled 266 volunteers who are young and healthy but previously inactive. They were randomized to six months of endurance training, high intensity interval training, resistance training, or to an unchanged lifestyle (control group).
The volunteers who were randomly allotted to three forms of exercise undertook 45-minute sessions thrice a week, and a total of 124 completed the study. The researchers examined the length of telomere and telomerase activity in white blood cells in blood sample of the participants at the beginning of the study, and 2-7 days after completing the six months of exercise.
Compared to start of the study and the control group, telomere length and telomerase activity were increased in participants who did endurance and high intensity training, according to study leader Professor Ulrich Laufs. These two factors are important for cellular aging and regenerative capacity, resulting into healthy aging. However, resistant training did not exert such effects.
Telomerase activity was improved 2-3 folds and telomere length increased remarkably in the endurance and high intensity training group compared to resistance and control groups. According to Prof, Laufs, since it is identified that the two forms of exercise promote healthy aging, the study may help develop future studies on this key topic, accompanying telomere length as a biological age indicator.
The study has multiple implications, the data supports guideline recommendations by European Society of Cardiology that resistance exercise should be complementary to endurance exercise rather than a substitute. The data detects telomere length and telomerase activity as critical ways to measure effects of various forms of exercise at cellular level. The researchers said that these measurements could be used in guide training recommendations for people which may improve the efficacy of exercise in preventing cardiovascular disease.