Researchers have found evidence that endurance exercise, such as running, swimming, cross-country skiing and cycling, will help you better than resistance exercise, which involves strength training with weights.
In a study published in the European Heart Journal Today, researchers in Germany looked at the effects of three types of exercise-endurance training, and they found that endurance and high intensity training both slowed or even reversed cellular aging, but that resistance training did not.
Our DNA is organized into chromosomes in all 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 are shorten and this is an important molecular mechanism for cell aging, 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, Germany, enrolled 266 young, healthy but previously inactive volunteers and randomised them to six months of endurance training (continuous running), high intensity interval training (followed by four bouts of the high intensity running with slower running, and then a final cool down of slower running), circuit training on eight machines, including back extension, crunch, pulldown, seated rowing, seated leg curl and extension, seated chest press and lying leg press), or to an unchanged lifestyle (the control group).
The participants who were randomized to the three forms of exercise underwent three 45-minutes sessions a week, and a total of 124 completed the study. The researchers analyzed the telomere length and telomerase activity in the blood of blood, and after two to seven days after the final bout of exercise six months later.
Prof Laufs said: "Our main finding is that the volunteers who did endurance and high intensity training, telomerase activity and telomere length increased, which are both important for cellular aging, regenerative capacity and thus, healthy aging. Interestingly, resistance training did not exert these effects. "
Telomerase activity was increased by two to three fold and telomere length significantly increased in the endurance and high intensity training groups compared to the resistance and control groups.
"The study identifies a mechanism by which the weight of training is improving the health of aging.It may help to design future studies on this important topic by using telomere length as the indicator of 'biological age' in future intervention studies," said Prof Laufs.
Co-author of the study, Dr. Christian Werner, of Saarland University, Germany, said: "The study has many implications: our data support is that the resistance exercise should be complementary to endurance training rather than a substitute. Using this measurements to guide the training recommendations for individuals may both improve both the exercise and efficacy of exercise training programs in preventing cardiovascular disease. "
Previous research has shown that longer telomeres and increased telomerase activity are associated with healthy aging. However, this is the first prospective, randomized controlled study of the effects of different forms of exercise on these two measurements of cellular aging.
Prof Laufs said: "Physical exercise is widely recommended, but they are a great effort and there are no funding sources from the industry. This is the largest randomized study comparing well defined training modalities with a control group and with a long duration of six months.We hope that our project will stimulate confirmation and further studies in this field. "
A possible mechanism that may explain why the endurance and high intensity training can increase the telomere length and telomerase activity is that these types of exercise affect levels of nitric oxide in the blood vessels, contributing to the changes in the cells.
"From an evolutionary perspective, endurance and high intensity training may mimic the advantageous travelling and fight or flight behaviour of our ancestors better than strength training," said Dr. Werner.
Limitations of the study include the fact that the number of participants is small, even though it represents the largest study to investigate this in a prospective and randomized control path; and the everyday activities of the training sessions may have included elements of the other forms of exercise, but this would be in all groups, including the control group.
In an accompanying editorial by Professor Konstantinos Stellos and Professor Ioakim Spyridopoulos, from Newcastle University and Freeman Hospital, Newcastle Upon Tyne, UK, who did not involve in the research, write that so far there was no evidence that played by telomerase to maintain telomere length is implicated in the onset of cardiovascular disease, except maybe for heart failure. Rather, it appears that the acceleration in the telomere shortening may be a sign of increased oxidative stress and a higher turnover of cells, coinciding with diminished telomerase activity. However, telomerase leads to enhanced nitric oxide, reduced oxidative stress, reduced damage to cells' DNA and reduced cell death, which are all important for delaying the clogging up of arteries with fatty deposits. They conclude that the findings from the study by Dr. Werner and Prof Laufs "clearly underscore the advantage of aerobic endurance training compared to resistance training in cardiovascular ageing".
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"Differential effects of endurance, interval and resistance training on telomerase activity and telomere length in a randomized, controlled study", by Christian Werner et al. European Heart Journal. DOI: 10.1093 / eurheartj / ehy585
"Exercise, telomerase activity and cardiovascular disease prevention," by Konstantinos Stellos and Ioakim Spyridopoulos. European Heart Journal. DOI: 10.1093 / eurheartj / ehy707