Berlin: Endurance exercise, such as running, swimming, cross-country skiing and cycling, will help you age better than resistance exercise, which involves strength training with weights, a study has found.
The study, published in the European Heart Journal, looked at the effects of three types of exercise -- endurance training, high intensity interval training and resistance training -- on the way cells in the human body age.
Researchers from Leipzig University in Germany found that endurance and high intensity training both slowed or even reversed cellular ageing, but that resistance training did not.
Our DNA is organised into chromosomes in all the cells in our bodies. At the end of each chromosome is a repetitive DNA sequence, called a telomere, that caps the chromosome and protects its ends from deteriorating.
As we grow older, the telomeres shorten and this is an important molecular mechanism for cell ageing, which eventually leads to cell death when the telomere are no longer able to protect the chromosomal DNA.
The process of telomere shortening is regulated by several proteins. Among them is the enzyme telomerase that is able to counteract the shortening process and can even add length to the telomeres.
The researchers led by Professor Ulrich Laufs of Leipzig University enrolled 266 young, healthy but previously inactive volunteers and randomised them to six months of endurance training, high intensity interval training, resistance training, or to an unchanged lifestyle.
The participants who were randomised to the three forms of exercise undertook three 45-minutes sessions a week, and a total of 124 completed the study.
The researchers analysed telomere length and telomerase activity in white blood cells in blood taken from the volunteers at the start of the study, and two to seven days after the final bout of exercise six months later.
"In volunteers who did endurance and high intensity training, telomerase activity and telomere length increased, which are both important for cellular ageing, regenerative capacity and thus, healthy ageing. Interestingly, resistance training did not exert these effects," Laufs said.
Telomerase activity was increased two- to three-fold and telomere length was increased significantly in the endurance and high intensity training groups compared to the resistance and control groups.
The study identifies a mechanism by which endurance training -- but not resistance training -- improves healthy ageing.
"It may help to design future studies on this important topic by using telomere length as indicator of 'biological age' in future intervention studies," said Laufs.
