Updated: Feb 14
This month I’ll be 58 years old. I’ve thought a lot about movement as I age and how it contributes to healthspan and longevity. While most have heard the recommendation to move 30 minutes per day, and the official recommendation is 150 minutes of moderate exercise per week, I wanted to take a different approach to movement and structure it around three specific concepts:
Maximizing Metabolic Health
Maintaining Insulin Sensitivity
Prevention of Injuries
Looking at movement from these perspectives provides a different lesson how to look at long term health. The intent is to extend, as long as possible, your ability to enjoy life, do the activities you want to do and stay independent for as long as possible. My personal goal is to be skiing, one of my favorite activities, well into my 80s.
Stop and think what you do today, or want to do today, and cast your mind 30 years into the future. What do you need to do today to build that foundation for years to come?
How do those three concepts allow us to achieve our 30 year goals?
Maximizing Metabolic Health
A few facts. Over time your tolerance for certain activities—picking up groceries, chasing after children (or grandchildren), running up and down the stairs, etc.—wanes. Why is that?
We know that cardiac output—how much blood your heart pumps per minute—slowly decreases over time in response to stress. This is due to several factors, including a decrease in the number of cardiac cells (myocytes) as well as a thickening of the heart valves and major blood vessels over time even absent hypertension.
We also know that the energy provided by mitochondria, commonly referred to as the "powerhouse" of your cells, decreases 8% per decade from our 30s as we age. There are thousands if not tens of thousands of mitochondria per cell in your body.
Both of these factors contribute to a loss of exercise tolerance over time. It starts at the cellular level and impacts every system in your body.
So, how do you improve "Metabolic Health"?
Zone 2 Training
There is an important concept called Zone 2 exercise (also called Zone 2 training). Zone 2 training has been shown to increase both the number and the efficiency of mitochondria in your cells.
Exactly what is Zone 2 training? Physiologically it refers to your body being at your "lactate threshold," which is the point at which your body switches from mostly fat oxidation (burning fat for fuel) to using glucose or sugar. Once you pass the lactate threshold your body begins to build up lactate. In most people burning lactate produces an excess of hydrogen ions resulting in the common "burning" sensation people describe.
It is used by competitive athletes, including riders in the Tour de France, for 70-80% of their total training! This is "base training." Think of building a wide base so you can climb higher.
Studies show that the longer you stay in Zone 2 some amazing things happen over time:
Increase in the number and efficiency of your mitochondria
Lowers resting heart rate and blood pressure
Lowers the risk of injury
Improvement in insulin resistance (more on that in the next section)
Improvement in ability to deal with increased resistance and load
How to Train In Zone 2
How do you train in Zone 2? Actually, it is a lot less intense than you think.
When I speak to my patients about Zone 2, I describe working to a relatively perceived effort (RPE) of mild to moderate intensity. This means you are still able to carry on a conversation like speaking on the phone, but someone would know you are exercising. You should be able to stay in Zone 2 for hours. Common activities would be walking briskly on a treadmill at a 7-10% incline, biking on a trainer to maintain a consistent output or low intensity work on a Peloton.
There are several methods to assess whether you are in Zone 2, from simple and less accurate to more complex and more accurate:
Heart rate formula of (220-your age) x 0.7
Karvonen Formula Target Heart Rate = [(max HR − resting HR) × 0.65] + resting HR
Perform a Fit test to determine maximum heart rate
Measure your lactate threshold at the end of your workout and target 1.8-2.0 mmol/liter after a 45-60 minute workout
The lactate level is the most scientifically accurate. The Karvonen formula is the best calculated since it incorporates resting heart rate and gives a better approximation of your actual target heart rate for a particular zone.
That should be done for 45 to 60 minutes twice per week. It is also acceptable to add a short period of higher intensity, zone for work, after completing 45 minutes of zone two.
Maintaining Insulin Sensitivity as we age
The second component of maintaining fitness as we age is the focus on insulin sensitivity.
A simple way to think about insulin sensitivity is that the pancreas, the organ that secretes insulin in response to a meal, has to excrete less insulin than those who are insulin resistant. We know that 50% of all adults over age 65 are pre-diabetic, and over 25% are diabetic. That is three out of four of every adults over 65 years of age!
Insulin resistance is related to many factors and worsens over the decades. What most people do not realize is 70 to 90% of glucose disposal (or removal of glucose from your bloodstream) after a meal is into your skeletal muscle for storage as glycogen and to be used immediately for energy. The loss of skeletal muscle over time increases your risk of insulin resistance and diabetes. By the age of 65, the average adult has lost 25% of their skeletal muscle in comparison to their 30s.
The loss of skeletal muscle is both a hormonal issue as well as a disuse issue. Hormones like growth hormone and testosterone decrease as we age, for men and women. The lower amount of activity we do as we get older, like sitting behind a desk, contributes to the disuse problem.
What should we do to maintain or build muscle as we age?
Move every day for 30 minutes—start with walking
Strength building compound movements slowly and gradually overtime should be part of any long-term fitness routine
The goal is to build up your core muscle strength and increase total muscle mass overtime. As well as improving insulin sensitivity, these types of movements have been shown to lower rates of depression and improve overall sense of well-being.
Finally, strength training can happen at any age. I have advised women in their 50s and 60s to start strength training with great results. If you have the means, meet with a personal trainer for a few sessions to devise a plan focused on core strength. It will pay health dividends resulting in better longevity and healthspan.
Minimize Injury Risk
The final component of a movement routine is minimizing injury risk. As we age, the risk for falls becomes a real issue. Focus on injury prevention involves three areas:
Intentional stretching to maintain joint mobility
Isolated single leg movements to improve and maintain balance
Use of the simple foam roller for muscle recovery
While stretching is important at any age the older we get the gentler we need to treat our bodies. Simple principles like a few minutes of dynamic stretching prior to working out followed by a few minutes of static or dynamic stretching after intense exercise helps with recovery and lessens the risk of injury.
Balance worsens as we age. It is a simple fact of life. As I have aged, I have been very intentional about working in single leg movements like squats and lunges at least once per week. When starting, hold onto a sturdy chair or the wall. Over time, you’ll gain more confidence as your balance improves. Other ways to improve balance include Eastern movement techniques like Tai Chi or Qi Gong. These are deceptively simple and over time will ad stability and balance to your overall fitness level.
Recovery through simple activities like foam rolling or massage both feels great and lessens the likelihood of injury. As I have begun doing this over the last few years, it has improved recovery, especially from strenuous activities. And, it just feels great.
So that was a lot. In summary, the intent as we age should be focused on three key areas:
Improving metabolic health through zone two training
Maintaining insulin sensitivity by building muscle mass regardless of age
Focus on injury prevention through stretching, improving balance and muscle recovery
By incorporating these principles into your movement and fitness rate regimen you extend longevity and improve your healthspan.