Aerobic Exercises Key To Aging Well?

Me on the left. Picture by Jeffrey Keng from Cycleworx

Slightly more than a year ago, I wrote that strength training may be just as important (if not more) than aerobic exercises. Why? Strength training has been found to decrease rates of early and cancer related death.

And earlier this year I disagreed with a funded study by Les Mills International when the article suggested that lifting weights was more beneficial for losing weight compared to running or cycling (aerobic exercises).

Now, some new research seems to show that aerobic exercises (like running, cycling, rowing or swimming) can make our cells younger. That same study found that weight training may not cause the same physiological changes in our cells.

Way back in 2009, a study found that competitive middle-aged runners had extended telomeres compared to inactive people of the same age. What are telomeres? All of us have telomeres at the tips of our chromosomes. Telomeres help protect our cells from damage and have been found to shorten and fray as a cell ages.

Many of the researchers in that 2009 study came together for this recent study to investigate whether exercise would change our telomeres.  They also wanted to know what type of exercise were needed and whether intensity played a part. It is hypothesized by the scientists that exercise helps lengthen the telomeres.

The researchers recruited a group of healthy middle aged men and women who did not exercise. They were tested for  their aerobic fitness and telomere length. In addition, blood markers of telomerase (an enzyme that influences telomere length) were tested as well.

Some in this group were randomly assigned to continue with their lives as normal as a control group. They did no exercises.

Others started a supervised program of brisk walking or running for 45 minutes three times a week or a high intensity interval program of four minutes of strenuous exercise followed by four minute rests with this repeated four times.

A third group took up weight training, doing a circuit of resistance exercises three times a week.

Heart rates were monitored and the exercise program was carried out for six months. Results were tested after this and all the subjects who exercised were found to be more aerobically fit.

At molecular level however, there were differences. Those who did the aerobic exercises and interval training had much longer telomeres than before starting the exercise program and more telomerase activity.

Those who weight trained and those in the control group (who did not exercise) had no change in telomere length. Some even had shortened telomere lengths.

Those who did weight training produced less nitric oxide, which is thought to affect telomerse activity and contribute to lengthening telomeres.

Even though weight training was strenuous, overall heart rate was lower compared to running in the study. This results in less blood flow and probably less physiological response from the blood vessels.

The researchers suggested that exercise needs to be aerobically taxing to extend telomere length and slow cellular level aging. In this aspect, endurance exercise was clearly ahead of resistance training.

The findings do not indicate that weight training does not combat aging as it also helped improved fitness, which itself is a very important indicator of longevity.

Like I wrote before, current research shows that both strength training and aerobic exercises are necessary to be healthy and functional. So run, bike or lift weights, (or whatever exercise you prefer) as they are all beneficial, it's much more important to keep moving.

I wanna for live a long time, so I lift weights too

References

Werner CM, Furster T et al (2009). Physical Exercise Prevents Cellular Senescence In Circulating Leococytes And In The Vessel Wall. Circulation. 120 (24): 2438-2437. DOI: 10.1161/CirculationHA.109.861005.

Werner CM, Hecksteden A (2018). Differential Effects Of Endurance, Interval And Resistance Training On Telomerase Activity And Telomere Length In A Randomized Controlled Trial. Euro Heart J. ehy585. https://doi.org/10.1093/eurheatj/ehy585.