by Dr. Kara Fitzgerald
The right kind of exercise is an anti-aging elixir that spins the biological clock in reverse: when you look at the lifestyle habits of healthy centenarians, a commonality among all of them is that movement is a foundational part of their life. Alongside nutrition and other lifestyle practices, exercise is a core component of the Younger You program.
Exercise as a DNA Methylation Adaptogen
A big reason that movement is such a vital component of health and longevity is that it regulates the epigenome (our gene expression controls), including via DNA methylation. Positive, exercise-induced DNA methylation changes have been found in the following areas:
- Obesity, diabetes, and fat storage (this particular study showed profound, beneficial changes in type 2 diabetics who started exercising in just six months!)
- The inflammatory response and inflammation-associated diseases, when moderate exercise is practiced regularly over time
- Learning, memory, and neuroplasticity (the ability of brain cells to form new connections)
- Suppressing cancer – and this effect is more pronounced the older you are
- Reverting global DNA methylation patterns to those of a younger person
- Our exercise habits are heritable! You can hand down DNA methylation changes (favorably or not) to your offspring. Can you hand down those 6-pack abs? Probably not, but you can lower risk for diabetes and heart disease in offspring based on your habits. Wow.
How Fit Are You?
You can’t manage what you don’t measure, right? Quantifying your fitness is a good start to any exercise program. As is assessing your current rate of biological aging. In addition to finding out just how much you need to do, you can track your progress over time to make sure you’re on the right track.
For quantifying fitness, I like this online quiz developed by researchers at the Norwegian University of Science and Technology. They developed a way to quite accurately predict VO2 max, a common tool used to understand fitness levels, without having to take a cardiopulmonary exercise test at your doctor’s office. You can access it here: https://www.worldfitnesslevel.org/#/ (you’ll need to know your maximum heart rate (pulse), resting pulse, and waistline measure first).
For bio age assessment, I recommend using my at-home lab test package.
Your Foundational Aerobic Exercise Prescription
A reasonable starting goal – what we asked of our study participants, and the requirement for the Younger You Intensive program – is to aim for a minimum five sessions per week of at least thirty minutes at a moderate exertion level. As far as what kind of aerobic exercise to do, we told our study participants to do something they loved, and suggested brisk walking, light jogging, hiking, dancing, yard work, bicycling, and swimming as activities to consider. These guidelines are also suitable for everyday longevity support.
Your goal during aerobic exercise is to reach an intensity of 60 to 80 percent of maximum perceived exertion (PE) – that means you’re still able to carry on a conversation, although you might be sucking a little bit of wind in order to do so. You don’t need to wear a heart rate monitor or fancy biometric tracking device, as research suggests that using PE alone is about as reliable as using fancy tracking equipment.
Adding on High-Intensity Interval Training
When you’re ready, you can add in bursts of more intense exercise, such as the aptly named high-intensity interval training (HIIT), where you alternate periods of pushing hard for a short amount of time (somewhere between thirty seconds and one minute, typically) with periods of rest (generally for about half the time you go all out). There is a body of research on HIIT that suggests that it provides extra benefits beyond basic aerobic exercise, which is why we often layer it on when working 1-1 with individuals. Research has shown HIIT to be effective at:
- Boosting brain power
- Burning fat
- Lowering insulin resistance
- Improving markers of cardiovascular health
“High intensity” means you are going “all out” and reaching 90 percent or higher perceived exertion – your breathing is strained, it’s impossible to keep up a conversation, and your muscles are fatiguing quickly. The good news is that you only maintain this level of intensity for two minutes or less. You can either incorporate your HIIT into your regular workout – walking up a few hills as quickly as you can, if you’re walking, or sprinting if you’re jogging – or you can perform a workout that is specifically designed to intersperse short intervals of exertion and rest – like the famous seven-minute workout. If you choose to do HIIT workouts, they should be in addition to, not in replacement of, your five thirty-plus-minute exercise sessions per week.
Adding on Resistance Training
As we age, we lose muscle mass. Exercise, and specifically resistance training, is important for helping to preserve that muscle mass. Why is this important? – We know that losing muscle mass and strength is linked with an increased risk for disease and mortality. One reason is that lean muscle is important for healthy metabolism, keeping glucose and lipid management (especially triglycerides) in check.
Resistance training doesn’t focus on increasing your heart rate as much as it is about targeted muscle workout. Examples of this type of exercise include squats, sit ups, lunges, planks, and weight lifting. Some of these you’ll get from a pilates or yoga class – you don’t always have to head to the weight room. It’s a good idea to get a qualified trainer to help you set up a resistance training program that’s suited to your body and needs.
Adjusting Your Protein Intake
We also know that as we age, we need to consume more protein in order to be able to maintain muscle mass. The reasons for this include the fact that our bodies gradually become less efficient at digesting, absorbing, and using protein as we get older. Our protein requirements also go up when we up our exercise levels. Read more about my thoughts on protein intake, especially as we age, here: The Protein Magic Formula.
I do recommend considering a protein supplement. Mostly because I routinely see individuals struggle to meet the increased protein requirements as they age. For vegans and vegetarians, I consider a protein shake essential. Here are a few that I recommend:
Hormesis and the U-Curve of Exercise Benefit (Backing off From Over-Training)
Believe me, I understand the lure of intense exercise: I was a competitive cyclist in medical school, and it was one of the happiest, and most arduous, times in my life. I was also sick with sinusitis during that time quite often because I was always pushing myself scholastically and on the bike – I didn’t understand the importance of recovery then. I’ve not had sinusitis once since graduation, which also coincided with the end of my competitive cycling career.
Exercise triggers what’s known as hormesis, or a biological process where a beneficial effect is triggered by a limited exposure to something harmful or challenging to the body. You probably know that lifting weights causes microtears in the muscle that the body then knits back together to make it bigger and stronger. A similar process happens within cells, too: exercise causes a transient increase in mitochondrial free radicals (mitochondria are the energy factories within your cells). Free radicals are destructive molecules, which might seem like a bad thing until you consider that those free radicals induce a hormetic response where your antioxidant system is ramped up to counter them. As a result, every time you exercise, your mitochondria are drenched in the potent antioxidant elixirs that only our body can make.
It’s important to note that you want just enough exposure to free radical stress, as too much can be definitively damaging. Like most things, exercise has a U curve of benefit, and exercise that is too extreme breaks the body down in greater amounts than it can recover from. A 2018 study found that Polish elite athletes, especially those involved in power sports (such as competitive weight lifting), were significantly biologically older than healthy controls of similar mean ages. This suggests a sweet spot for exercise, which may be more or less than what you are currently doing.
DrKF’s Exercise Routine
Cycling is still my sport of choice, and I still like to get my heart rate up and work up a good sweat, but I have dialed the intensity and duration down somewhat from my days of more intense competitive riding. Because sitting is the new smoking, I also invested in a treadmill desk at work that I walk on, very slowly, for one or two hours a day, or that I just use as a standing desk. And I’ve built a few core exercises and some gentle yoga poses into my getting-ready-for-bed wind-down routine. They keep my lower back supple, strong, and pain free and help me relax a bit before sleep.
When it comes to resistance training, I am doing strength training with weights. Recently, following on from conversations with Dr. Stacey Simms (I’ll be podcasting with her soon so you’ll get to hear it too), and then experimenting with variations in my workout, I’ve learned that I can achieve better results with higher weights and fewer repetitions (Stacey proposes that it’s women-specific physiology that allows us to follow this shortcut and get better results; we don’t apparently require the same amount of rest time in between sets also). I tried this in Mexico while I was there for two months and it slimmed my workout routine down to less than 30 minutes. Interestingly, now that I’m back at my US gym, returning to what I was doing here before, I can see that I’m actually stronger for it.
What’s your exercise routine and favorite forms of exercise? Let me know, as well as any feedback you have, in the comments below.