What Type of Exercise Should I Do?
New research once again points to health and longevity benefits of endurance exercise compared to resistance training. Now, no one is suggesting resistance (weight) training is in any way harmful— numerous studies tout its many health benefits, as they do with any type of physical exercise.1,2
Recently, however, a handful of studies have measured protective and longevity benefits of exercise by measuring effects on length of the protective caps of DNA chromosomes, called telomeres.
Stress and aging have been shown to shorten telomere length. Elizabeth Blackburn won the Nobel Prize in 2009 for her discovery of the link between shortening of telomeres and accelerated aging process.3 Since then, numerous researchers have set out to discover ways to lengthen and protect telomere length.
We Recommend3 Herbs to De-Stress + Lengthen Your Telomeres
For Telomeres: HIIT, Endurance, or Weights?
In a 2018 study in the European Heart Journal, researchers measured telomere length and telomerase activity in 124 healthy but inactive adults for six months. Telomerase is an enzyme that blocks telomere degeneration or shortening.4,6
This study divided volunteers into three exercise groups and a control. One group performed high-intensity interval training, one aerobic endurance training (continuous running), and the final group resistance weight training. The control group was asked not to make any changes in lifestyle or activity. Each exercise group performed a 45-minute workout three times per week for six months.
Aerobic endurance training consisted of continuous running at a long, slow, duration pace. Interval training employed a classic 4×4 method, consisting of a 10-minute warm-up at 60–70% maximum heart rate, followed by 4-minute high intensity intervals at 85–95%. There were 3-minute active breaks at 60–70% maximum heart rate between each interval, and the session ended with a cooldown.5 Resistance training included a circuit of eight weight-lifting exercises on machines: back extensions, crunches, pulldowns, seated rows, seated leg curls, seated leg extensions, seated chest presses, and lying leg presses.4,6
The study concluded that aerobic endurance training and interval training (both endurance activities), but not resistance training, increased telomerase activity (protection form shortening of telomeres) and telomere length, which are important for cellular longevity, regenerative capacity, and, thus, healthy aging.4,6
Should I Stop My Resistance Training?
Researchers in this study are not suggesting that endurance training replace resistance training, as there are numerous health benefits from resistance training, such as positively affecting health risk factors like insulin resistance, resting metabolic rate, glucose metabolism, blood pressure, body fat, and gastrointestinal transit time, which are associated with diabetes, heart disease, and cancer.2
The study does suggest resistance training be combined with endurance training and that it is best not to perform resistance weight training alone, although more research is needed here.4,6
Ayurvedic Breathing, Yoga + Meditation Lengthen Telomeres
The strong relationship between stress, aging, and shortening of telomeres was well-documented by Elizabeth Blackburn’s original research.3 Since then, studies have been done on yoga, breathing, and meditation that have also shown lengthening of telomeres, suggesting these practices extend life.7
Research once again suggests the benefits of nose breathing versus mouth breathing during exercise, and in particular during long-distance endurance exercise, where the greatest telomere lengthening was found.
In my book on nose-breathing exercise, Body, Mind, and Sport, I cite stories of ancient runners who would run with pebbles or water in their mouths to force them to breathe through their noses.
Nose Breathing + Nitric Oxide
One of the mechanisms for increased telomerase and longer telomeres is production of nitric oxide, the Nobel Prize-winning “panacea” molecule. Follow-up research has found nitric oxide is produced during nose breathing and not during mouth breathing. Nitric oxide is produced in the paranasal sinuses and delivered into the lower, more vascularized alveoli of the lungs during nose breathing (and only minimally during mouth breathing).8
We also published brainwave studies on nose versus mouth breathing to prove that nose breathing may be the factor in producing “runner’s high.” We found a burst of coherent alpha brainwave activity during nose- versus mouth-breathing exercise, suggesting that more meditative, calm, runner’s high brain functioning was established during nose breathing.
Many factors could explain this phenomenon, but increased production of nitric oxide during nose breathing may explain this calming effect during vigorous exercise. During vigorous exercise, brainwave function is typically stressed, demonstrated by an increase of beta-wave activity and incoherence, which is what we saw in our study.9,10
Read my articles on the benefits of nose breathing exercise and how to do it here.
The Bottom Line
If your goal from exercise is a longer, healthier life, make sure that a good portion of it is endurance nose-breathing activity. Enjoy the high while taking care of your telomeres!