Benefits of Physical Activity, some thoughts about Intensity and How to Cut Your Risk of Premature Death by 33%
So I’ve been researching the benefits of physical activity on healthy aging a lot lately. Of course, as a PT, I’m well-aware that exercise is good and we should all be doing it, but I’ve been doing a deeper dig lately into the actual specific effects on our health as I develop my therapy programs. Beyond identifying the benefits, the next step is learning how acheive them. This has led me to topic of intensity. Yes, for those of you who know me, you can stop your snickering, I’m aware I can be a *little* intense sometimes and you may find the idea of me actually having to put research into this topic a little amusing. But in reality, the topic of intensity is actually quite pertinent to healthy aging. You see, the older adult is chronically underdosed in exercise intensity by well-meaning therapy clinicians and the medical profession in general when it comes to exercise prescription. Underdosing translates into wasted efforts, and poorer health outcomes. I want better for my patients.
The first step in understanding how to better prescribe exercise to promote health and wellness in the older adult is to understand what is required to achieve said benefits. The CDC issued a well-researched and thoroughly detailed 117 page document in 2018 entitled ‘Physical Activity Guidelines for Americans,’ and after reading all 117 pages, I started wondering if I am I even getting enough exercise at an adequate intensity. While you’re more than welcome to read the document in it’s entirety yourself, for those of you satisfied by a summary, I’ll share a brief cliff-notes of the relevant details here.
Americans do not exercise enough. The average American sits for 55% of their waking time, or around 7.7 hours hours per day. This number only increases in the older adult. The average 70-85 year old American sits for 9 hours per day. This doesn’t take into account time spent SLEEPING.
28% of adults over the age of 50 are physically inactive. Physical activity levels are graded from Inactive, to Insufficiently Active, to Active, to Highly Active. Adults who are physically inactive do not get any moderate or vigorous physical activity beyond the basic movements involved with daily life. Insufficiently active adults exercise, but at less than the recommended amount. Active adults hit their target movement goals and Highly Active adults surpass them.
Inactivity is 30% higher in those with a chronic disease. 6 in 10 Americans live with at least 1 chronic disease. 4 in 10 have two or more.
To qualify as Active, you must regularly participate in the recommended level of exercise as described in the Physical Activity Guidelines for Americans. These guidelines state that to get optimal health benefits from physical activity, you should:
Perform 150 to 300 minutes of moderate intensity physical activity per week.
Participate in regular moderately challenging strengthening activities at least twice per week that target all the major muscle groups.
For older adults, the Guideline goes on to suggest every older adult should include balance training as part of their regular, weekly multicomponent exercise routine.
Where do you fall ? Are you Inactive, Insufficiently Active, Active or Highly Active? Could you do better?
And now for the good news. IF you are able to participate in this level of activity, you will not only be 33% less likely to die of unnatural causes, but you also reduce your chances of developing or experiencing:
Dementia, by 30%
Hip fractures, by 68%
Cardiovascular disease, by 35%
Type II diabetes, by up to 40%
Colon cancer, by 30%
Breast cancer by 20%
If this isn’t enough to convince you, regular physical activity has further health benefits on your cardiovascular system, pulmonary system, muscle, joint and bone health, neurological function and emotional health, helps you sleep, has a large role to play in weight management and can reduce your risk of falls, and falls-related injuries significantly. And also, it improves your quality of life. Yes, this has actually been proven.
So back to the question I found myself posing earlier. Am I getting enough physical activity to garner me all of these health benefits? I mean, I’m an active person, and I pretty much never sit still. I try to exercise throughout the week, though some weeks I’m better than others. Some days I cycle, but others I just feel like taking a walk or doing some yoga, and I try to respect what my body tells me I need. Before you, too, try to figure out whether you getting enough exercise, I want to take a moment to explain the concept of Intensity. What is ‘moderately intense’ physical activity anyways?
Exercise Intensity
A general description of exercise intensity is how hard you have to work to perform an activity. It can be further broken down system-specifically, in regards to how hard you heart has to work, how hard your lungs have to work and how hard your muscles have to pump to make the activity happen, but in a general sense, exercise intensity refers to how taxing the activity is on your body. The most specific way to measure intensity (without a whole bunch of treadmills, EKG tabs and pulmonary function tests) is to determine the percent your heart is working of its maximum capacity. You can use an online calculator, or do some simple math (220-your age) to determine your maximum heart rate, then multiply by the desired intensity to calculate your intensity range. Per the CDC, intensity ranges per percent of heart rate maximum are as follows:
Light Intensity is activity that places you at 50-64% of your heart rate maximum.
Moderate Intensity is activity that places you at 64-76% of your heart rate maximum.
Vigorous Intensity is activity that places you 77 - 93% of your heart rate maximum.
Now of course, there are all sorts of variables that go into your true heart rate maximum, and your ability for your body to reach these levels (use of beta blockers is a big one!), but to give you a sense of what this translates to, for an average 50-year old, the heart rate range for light intensity is 85-106 beats per minute, for moderate intensity is 109-129 beats per minute, and for vigorous intensity is 130 - 158 beats per minute. For a 75 year old, these values drop; for light intensity the range is 72-92 beats per minute, for moderate intensity the range is 93-110 beats per minute and for vigorous activity the range is 111 - 134 beats per minute. As you would expect, this means that the same active I perform at 37 years old, would likely be more taxing for someone who is 50, and even more taxing for someone who is 75. This means exercise prescription for the older adult cannot be a simple cookie-cutter exercise class or online program. It requires an educated health profession (a PT perhaps…) to take into account all the health variables that may determine what your personal exertion ranges can and should be.
There are also a few subjective, but frequently, more useful measures to gauge intensity. The measure I use most frequently is called the Rate of Perceived Exertion Scale, or RPE. While the original tool used a 6-20 scale to self-report level of perceived exertion, a modified version has since been validated and uses instead self-rating on a 0-10 scale. I find this is more user-friendly for my patients, and I use it more often. When I use this scale, I explain 0/10 is when you are completely at rest, and 10/10 is running a marathon and you couldn’t possibly take another step. 5/10 is working hard, but you can maintain this level of exertion. This scale has been validated to correlate well with intensity as measured by heart rate ranges as above, and can be used in lieu of this measure of intensity for general purposes. To gauge how intense your physical activity with this modified RPE scale:
0-3 reflects a subjective experience of light intensity (rest, little to no fatigue or comfortable level of activity with slightly evaluated breathing rate - you should still be able to carry on a regular conversation)
4-6 reflects a subjective experience of moderate intensity (moderate, walking a brisk to rushed pace, breathing more deeply and level of activity more difficult to maintain - you should be able to talk, but not sing)
7-10 reflects a subjective experience of vigorous intensity (very strong, difficult to maintain level of activity, could not sustain for long, can barely talk)
So, if you find yourself in a session with me, wondering why the heck this PT lady is making you run around your house or get up and down from your chair so many times in a row, or even *gasp* lift weights (‘I’m 80-years old, why in the world does this chick have me deadlifting?’) it is because I am trying to get you what you deserve - the benefits of moderately intense physical activity and the most effective therapy treatment possible. The days of ankle pumps and seated exercise are behind us. We know better. You deserve therapy that not only fixes your pain and dysfunction, but helps you adopt a lifestyle that promotes health and wellness in more meaningful ways. And that takes participation in moderately intense, multicomponent regular physical activity. But your hard work will pay dividends; you will decrease your chances of developing disease and can increase your lifespan. Seems like a fair trade, right?
Getting your 150…
So back to me. With these thoughts in mind, I decided to check myself and see whether I am actually getting the recommended level of physical activity each week. I mean, if I can’t practice what I preach, what business do I have giving other people health and fitness advice? While I track my activity on my Apple Watch intermittently, I don’t often circle back to see what my weekly numbers are. I decided last week track my activity each time I exercised, and see where I wound up for the week. While I got plenty of exercise minutes, I was surprised to see how many of them didn’t qualify as moderately intense physical activity. Now, fortunately, this is likely reflective that I am in good cardiovascular health, and my never-stop-moving baseline level of activity doesn’t pose a physical challenge for me beyond light intensity. But that said, level of physical activity is person-specific; even if I’m active for the recommended number of minutes per week, if they aren’t at ‘moderate’ or higher level of intensity, I’m not going to get health benefits associated with an ‘Active’ lifestyle. All said and done, last week I worked out for 222 minutes. I only tracked my specific work out times, as I assumed none of my busy-body daily movements would be high enough to register as moderate activity. Of those 222 minutes, 155 of them qualified as moderately intense, while 68 of them registered as light. 2 of my workouts were bike rides, 2 of them were strengthening sessions and 1 was a 3 mile brisk walk around a local state park. So what did I take from my experiment? Of my five workout sessions, 30% of the time spent was not intense enough to garner the health benefits I am striving to achieve. And this is not to say that the light exercise I performed wasn’t worthwhile - some of was time spent in warm up, some of was walking that I do just to relax and some if it is the stretching and flexibility work I use to keep my back from bothering me. But, on the other hand, I barely broke the recommended minimum for moderate physical activity! I could absolutely be doing more. And I know I’m not the only one who struggles with this. I’ve heard from so many friends, colleagues and acquaintances that this year in particular, has made getting adequate levels of physical activity even harder. Many of us rely on getting out and going to work for our regular physical activity. Staying home has had a tremendous impact on all our our lives and daily rhythms. But with the stress of pandemic life higher than ever (oh dear god...school starts next week), it is even more important that we prioritize ‘getting our 150’ to help balance out the chronic stress and immobility that has unfortunately, become part of this pandemic life.
If someone told you there was a way to reduce your risk of dying early by 33%, wouldn’t you take it???
So back to you. How are you going to get your 150 this week? Do you need help? Extra motivation? Guidance? Have questions? I’ll post how I get my 150 each week if you post me yours. Keep an eye on my Facebook each week for a Getting Your 150 thread and share with me your plans, workout pictures and stats and lets celebrate together when we hit our goals. But don’t forget - something is better than nothing, so even if you start small, share your victories with me and I’ll root you on.
Need some extra help? Exercise is for everyone, even if you’re young, old, limited or living with a disability. My job as a physical therapist is to make exercise accessible. I am an expert at making exercise safe and efficient and enjoyable for people of all ages and abilities. I offer 1:1 Wellness Training and ongoing community education as part of my efforts to offer health promotion on a greater scale than I can with physical therapy alone. Check out these links to learn more.
HAE/FIT 1:1 Fitness Training
HAE/ED Community Seminars
Coffee Talks with Katie (Doctor of Physical Therapy)
References:
CDC Physical Activity Guidelines 2018
CDC Physical Activity Guidelines Executive Summary
