How many times have you heard about the importance of ‘diet and exercise’?
And how many times did that advice come from your doctor?
And how many times did the conversation end there?
One of the biggest travesties in our current medical system is this incomplete blanket prescription of “diet and exercise” given as a strategy to improve our health. It’s like if you were diagnosed with hypothyroidism and your physician recommended that you ‘take medication’ to treat it. Or if you had anemia and they said ‘iron might help.’ These recommendations aren’t very helpful without specific types, doses, frequencies, and measurable results.
But your physician is not to blame. It’s really not their fault. A 2021 study found that medical students receive an average of 3.96 hours of exercise related instruction during their clinical education (Adedokun et al.) and only 11 hours on nutrition. And a 2023 JAMA study found the average primary care visit time was 18.9 minutes. (Neprash et al.) So generally speaking, (unless they independently seek out the information) primary care physicians lack the educational background, expertise, and time to have a nuanced discussion explaining the intricacies of ‘diet and exercise.’ The vague recommendations often leave patients with more questions than answers.
Let’s imagine you’re following up with the doctor after some blood tests and you find out your A1C is elevated. 6.2%. Your doctor tells you that you’re pre-diabetic and on your way to type 2 diabetes if you don’t make some serious lifestyle changes. (This isn’t too far fetched since -unfortunately- 1 in 3 Americans are pre-diabetic and 1 in 10 are diabetic (National Diabetes Prevention Program)). Your physician explains that ‘diet and exercise’ are important and if they have a little extra time they might discuss dietary modifications to help control your weight and blood sugar.
You leave the office surprised and uncertain, but motivated. You know that getting your weight and sugar intake under control will fix this problem. So the next morning you skip breakfast. Instead, you dust off and lace up your running shoes. You hit the road for 2 miles as fast as you can and you finish in 25 minutes. But now you’re exhausted. You hadn’t run in over a year, maybe 2 miles was too much. All the sudden you start to feel weak, fatigued, maybe even a little disoriented. You get dizzy and sit down quickly so you don’t pass out. You just experienced exercise-induced hypoglycemia. This is something that can happen during or after intense exercise and is more common in individuals who have diabetes. It is easily avoidable with a little guidance, but can be frightening if you don’t know why it happened. An event like this can deter individuals from adhering to an exercise program.
A 25 minute maximal effort is very difficult, especially for someone who hasn’t been regularly exercising. The next day you are extremely sore. It’s hard to get out of bed and to stand up from the toilet. There’s no way you can lace up your shoes for another 2 mile run. This would also be easily avoidable with a little guidance but will also deter people from adhering to their exercise program and squash their motivation.
And you have questions. Is running 2 miles every day going to lower your A1C? Is it the only way? Are you working too hard? Or maybe not hard enough? How long do you have to keep this up for? Can you take rest days? What about your diet? Intermittent fasting? Keto? Joe Rogan talked about the Carnivore diet and he’s healthy, right? All of these questions can leave us feeling uncertain, and uncertainty is the impediment to commitment. But again, with a little guidance you can be confident that you are following an effective, efficient, and proven exercise program catered to helping you meet your goals.
So the general recommendation of ‘diet and exercise’ to improve your health status is setting you up for failure. We would like to try and clear up a few things regarding ‘exercise’ to help you reach your goals of living a longer, stronger, happier life.
First off, what is exercise?
Merriam and Webster’s definition is “bodily exertion for the sake of developing and maintaining physical fitness.” That isn’t very clear.
Island Performance Health defines exercise as “bodily exertion directed to develop and maintain your strength, muscle mass, aerobic efficiency, peak aerobic capacity, and stability.”
Now let’s cover each of those factors in a bit more depth.
Strength is measured by the amount of force you can exert, or how much weight you can lift. To improve muscular strength it is recommended to perform 3-5 sets of 5-7 repetitions. The weight should be heavy enough that you couldn’t do 10 repetitions and you need about 90 seconds rest between sets.
Muscle Mass is measured by the cross sectional of muscle, or how buff you are. To improve muscle mass it is recommended to perform 3-5 sets of 8-12 reps. The weight should be heavy enough that you couldn’t do 15 reps and you need about 60 seconds rest between sets.
Maximal Aerobic Efficiency is more commonly known as Zone 2 training. Technically speaking it is the greatest output you can maintain (think running or riding a bike) while keeping your serum lactate level below 2.0 millimoles. It is the maximum amount of work you can perform without triggering your anaerobic system. In real life it’s when your heart rate is about 60-70% of your max HR, or when you’re able to hold a conversation while exercising. This is the effort level you should maintain when doing 30-60 minutes of brisk walking, cycling, or swimming. To improve aerobic efficiency you will generally need to train about 3 hours per week at this intensity level.
Peak Aerobic Capacity is measured by your VO2 max. This is an uncomfortable test that measures the maximum amount of oxygen your body can utilize during high intensity exercise (think running 1 mile as fast as you possibly can). As previously discussed, improving your VO2 max drastically lowers your all-cause mortality. Your peak aerobic capacity can be improved by performing 4-6 rounds of 3-6 minute maximal efforts with a 1:1 work to rest ratio. This can be done on a rowing machine, bike, treadmill, or in the pool. It only needs to be done once a week. This type of exercise should only be performed by people who have previous experience with high intensity exercise and have consistently been performing zone 2 exercise training for 8 weeks.
Stability is the most general term we will use. Stability encompasses standing balance, single leg balance, dynamic balance, core strength, and posture. It is your ability to control movement, stay upright and balanced, catch yourself if you stumble, and pick things up from the floor without hurting your back. It’s your best tool for injury prevention.
As we discussed in the last post, exercise is by far the most effective intervention to improve your health-span and life-span. Research shows that if you have more muscle mass, more strength, and a higher VO2 max you will live longer and have a higher quality of life. Improved stability will reduce risk of injury and more importantly reduce the risk of falling as we age.
But how can ‘exercise’ help improve your elevated A1C?
It is well established that exercise and physical activity improves blood glucose control and can prevent or delay type 2 diabetes, along with positively affecting lipids, blood pressure, and cardiovascular events. The benefits of exercise on diabetes management are realized through both aerobic and resistance training. (Colberg et al.). Type 2 diabetes starts in the skeletal muscle. Skeletal muscle provides a major sink for glucose disposal and is therefore pivotally involved in maintaining blood glucose homeostasis. Up to 80% of the glucose oxidized after we eat a meal is oxidized in our muscles. However this process is disrupted if we have ‘metabolic dysfunction’ or ‘mitochondrial dysfunction’.
Zone 2 training is the best way to improve your metabolic health. It will specifically improve mitochondrial function (efficiency and volume). This will improve insulin sensitivity, lower blood sugar, and help weight loss. Improved mitochondrial function will improve your resting metabolic function too, so you will be burning more calories even when you’re sleeping. As mentioned above, the goal for zone 2 training is to work up to 3 hours per week of low intensity exercise at 60-70% of your max heart rate. But you should build up to this level slowly. If you haven’t trained recently we recommend starting with two 30 minute sessions per week.
Muscle mass impacts how much energy we use, too. Increasing our muscle mass will increase our total number of mitochondria. The more muscle we have the more glucose will get used. Muscle is metabolically active, fat is not. So if you are able to put on lean muscle mass (even if you don’t lose any fat) your insulin sensitivity will improve, your blood sugar will be better controlled, and it will be easier to lose weight. Having more muscle mass will improve your resting metabolic rate as well, so you will be burning more calories even when you’re sitting on the couch. As mentioned before, the goal for increasing muscle mass is 3-5 sets of 8-12 reps for each muscle group. We recommend starting with 3 sets of 8 reps and having two full body workouts per week (or one upper body and one lower body workout per week) and build from there.
High intensity interval training (HIIT) can also be a very effective tool to help control blood sugar levels, improve insulin sensitivity, and manage weight. But this type of exercise should only be performed after you are in a comfortable routine with zone 2 and weight training (at least 8 weeks). We will discuss HIIT and VO2 max training in greater depth in a subsequent post.
That was a lot of information. Mahalo for sticking through it with me. Hopefully it was helpful and hopefully it’s more clear why a routine doctor’s visit is not the place to have nuanced discussion about exercise.
This is why we believe so strongly that a Physical Therapist or other exercise specialist is integral in safely and effectively implementing an exercise program to meet your specific needs.
As always, if you have any questions about how to safely start your exercise journey or if you would like us to help you design your first 12-week exercise program please contact us!
Alohaaaa 🤙
Teddy Zabel, PT, DPT, OCS
Adedokun, Candace A., et al. “Analysis of American Medical Students’ Knowledge of Physical Activity Recommendations.” PRiMER, vol. 5, 16 Sept. 2021, https://doi.org/10.22454/primer.2021.249084.
Neprash, Hannah T., et al. “Association of Primary Care Visit Length with Potentially Inappropriate Prescribing.” JAMA Health Forum, vol. 4, no. 3, 10 Mar. 2023, p. e230052, https://doi.org/10.1001/jamahealthforum.2023.0052.
“About Prediabetes and Type 2 Diabetes | National Diabetes Prevention Program | CDC.” Www.cdc.gov, 8 Aug. 2023, www.cdc.gov/diabetes/prevention/about-prediabetes.html#:~:text=Diabetes%20Is%20Serious%20and%20Common&text=Today%2C%201%20in%2010%20US.
Colberg, S. R., et al. “Exercise and Type 2 Diabetes: The American College of Sports Medicine and the American Diabetes Association: Joint Position Statement Executive Summary.” Diabetes Care, vol. 33, no. 12, 29 Nov. 2010, pp. 2692–2696, https://doi.org/10.2337/dc10-1548.
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