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.

Barbells Or Bikes?

Both weight training and aerobic exercises are necessary

I came across this article recently which suggested lifting weights was more beneficial for losing weight compared to hopping on your bike for a ride or going for a run. The article suggested that burning calories via strength training will help you lose more fat than burning the same amount of calories doing moderate aerobic exercises.

Those headlines are good for creating media buzz but I'll say that it's not totally true if you look at that particular study in detail.

Now, before you say I'm biased, bear in mind I've written earlier how strength training is just as important as aerobic exercise. After not strength training for almost nine years, I started strength training again last year after I realize I was losing muscle mass with each passing year.

The study was funded by Les Mills International, a New Zealand company behind BodyPump, a barbell workout class. That means the study was commissioned by Les Mills International, thereby having a vested interest in promoting weight training.

There were only 12 female subjects in that particular study. They were tested during and after a resistance training workout (a BodyPump class) compared to a steady state moderate intensity session on a stationary bike.

In both workouts, the female subjects burned around 335 calories and had increase in levels of Human Growth Hormone (HGH), which is known for rapidly build muscle and to promote fat burning.

The women's HGH levels were 56 percent higher after the weight training session (light to moderate weights with high reps) compared to the steady state cycling session. Now, many previous research has shown increases in HGH levels in response to weight or resistance training, even in the elderly.

That's another reason why I resumed weight training, to make sure I get those doses of HGH, believed to be the elixir of youth, but that's probably another post.

For weight loss, the results were not unexpected as our metabolic rate stays up for a few hours after weight training. This ensures that more calories are being used even after training.

Bear in mind that strength training affects your body differently compared to aerobic (or cardio) exercises even if the calories burnt are similar. The headlines of this article generated by media buzz may claim that strength training is superior to cardio, but current research shows that both are necessary to be healthy and functional.

Actually, another study (Nindl et al, 2014) found that doing two hours of cardio boosted HGH secretion more than one to two hours of strength training.

As runners, cyclists and triathletes, we don't just exercise to burn a certain number of calories. I certainly don't. I do so because I love that adrenaline rush, the release of endorphins that I don't get with strength training. If I can solve some other problems while running, well, that'a a real bonus.

In my group rides, we don't always go at 68 percent heart rate (like the study), we do put the hammer down at times (at Coastal road), or surge up hills when we go up Mount Faber or NTU. I'm sure you do the same while riding with your friends or running intervals.

When we push the pace, our heart rate as well as our HGH levels soar. A study on sprint interval (Stokes et al, 2002) showed that doing just one 30 second sprint interval caused HGH levels to increase more than 430 percent!

Next time you feel your legs burning when your friends try to drop you, it's a good sign you're gonna have elevated levels of HGH.

So run, bike and lift weights, they are all beneficial but don't be too worried about counting how much calories you're burning.

If you're trying to lose weight, don't be too obsessive over what calories you are eating or what you are using.  As human beings, we are athletes, not Bunsen burners. Calories from drinking coconut juice or eating an avocado are processed differently by your body compared to drinking Coke or eating donuts or fried kuay tiao.


References

Harris N, Kilding A et al (2018). A Comparison Of The Acute Physiological Responses To BODYPUMP Versus Iso-caloric And Iso-time Steady State Cycling. J Sci Med Sp. DOI: 10.1016/j.jsams.2018.02.10.

Nindl BC, Pierce JR et al (2014). Twenty-hour Growth Hormone Secretory Profiles After Aerobic And Resistance Exercise. Med Sci Sp Ex. 46(10): 1917-1927. DOI: 10.1249/MSS.0000000000000315.

Stokes KA, Nevill ME et al (2002). The Time Course Of The Human Growth Hormone Response To A 6s And a 30s Cycle Ergometer Sprint. J Sports Sci. 20(6): 487-494.