are Glucose Monitors a Game-Changer or Wellness Gimmick?
continuous glucose monitors; a meer ten years ago this medical grade device was used by a small percentage of the population diagnosed with a metabolic disease such as type 1 or 2 diabetes. now, these devices are popping up across the internet from biohackers on social media to some of the most elite athletes in the world such as eliud kipchoge, the fastest marathoner in the world.
but what are they?
continuous glucose monitors, like the one used by kipchoge, are small devices that are stuck on the upper tricep through a long term adhesive, designed to be affixed for a period of time. once attached to the tricep, a micro-needle pierces the skin to come in contact with your interstitial fluid, a watery fluid that fills the space between cells, vital for transporting nutrients like oxygen and glucose. the device uses the needle to track real time changes in the concentration of glucose in this space.
tracking your glucose this way is a scientifically valid way for doctors and scientists to understand how efficiently your body metabolizes the food you eat.
but what even is glucose and why should we care?
glucose, what’s being measured by these devices, is a simple sugar molecule that your body uses for energy and is derived from carbohydrates. when you consume a carbohydrate (like bread for example) your body breaks that bread into microscopic pieces, typically glucose, fructose and/or galactose. however, glucose is the most common simple sugar found in blood because your liver rapidly converts fructose and galactose to glucose. since glucose is the most prevalent simple carbohydrate source in your blood, your body has adapted to primarily rely on it to create energy using it to power everything you do, from running a marathon to bending your finger.
but, the only way to convert glucose into energy is to transport it from your blood into your cells, where energy production occurs, which is where issues may arise and why tracking the concentration of glucose is even a thing.
now, in order to facilitate this transportation we need insulin. how does this work?
your body naturally releases insulin during both digestion and exercise. insulin has two jobs (1) pause the natural process your body does on the regular of creating glucose —termed gluconeogenesis (you’re already creating glucose from the food you just ate, you don’t need another cycle creating even more, that’d be crazy!) and (2) shuttle the free glucose from your blood into your cells to be used for energy.
if you don’t need energy at the moment your body stores those glucose molecules in your muscles and liver for short term storage as glycogen —you can quickly metabolize this stored glucose if you need to, let’s say, sprint away from a cheetah at a moments notice.
for long term storage, after your glycogen stores are fully saturated, you’ll store excess glucose as fat. this isn’t necessarily a bad thing as you can metabolize this glucose but it takes much longer and is second to storing glucose as glycogen.
to relate this to the real world, if you’re sedentary and overeat foods rich in carbohydrates and simple sugars —soda, candy, cookies, etc— you’re consistently flooding your body with an excess amount of glucose and making it harder on your body to remove that glucose. if you remember above, insulin helps transport glucose from the blood into the cells, when you consistently flood your body with an excess amount of glucose you can end up not being able to produce enough insulin for the amount of glucose in your blood. overtime, if this continues, your body can start not to not respond with the correct actions to insulin, this is termed insulin resistance.
when you can’t remove excess glucose from the blood a host of negative health consequences can arise such as cognitive decline and risk of stroke, kidney failure, blood clots, and fatty liver disease. This is because some organs (brain, kidneys, liver, and erythrocytes) don’t require insulin to absorb glucose, so they end up absorbing and storing more than they need. overtime this excess absorption can result in oxidative stress, inflammation and blood vessel damage leading to the diseases stated above. this can be serious and is what led scientists to develop medical grade glucose monitors in the first place.
by in large these monitors have been successful in helping metabolic patients understand what foods and exercise routines are right for them to maintain a steady glucose level and avoid excessive periods in hyperglycemia or hypoglycemia (high or low blood glucose/sugar).
so what’s good for one population is good for another, right?
health companies sure think so. according to abbott, the company that created and sells the device kipchoge uses, understanding your blood glucose (through their device of course) will “improve your health and wellness” by being, “the first step to providing you with unique insights about how your food, exercise, stress, or, in some cases, medication is impacting your health.” with the shift in wellness leaning towards wearables and trackers it’s no wonder companies have turned their attention to glucose monitors as a new market venture; advertised as a necessary health metric for healthy individuals but designed for and tested on diseased patients.
as a health and wellness professional I’m about as critical as one can get about “new” interventions touted to improve your health, and i’m especially critical when these claims come from a company or someone with influence, like kipchoge, talking about the positive impact a device can have on your health and performance. in 2021 kipchoge is quoted in saying, “using abbott… has transformed my training program. I am learning how my glucose levels relate to my running performance and have already started to see how quickly small adjustments can make a big difference."
interesting how big of an impact this device has had on kipchoge when four years prior to him using this device he broke the world record marathon time in berlin with a time of 2:01:39 (2018). then, a year later, he set another record for the first person to unofficially run a marathon in under 2 hours. I mean, how much more dominant can you get? i will give him credit however that he did break his own world record again at berlin running a time of 2:01:09 in 2022. could it have been due to his glucose monitoring? who knows.
for the vast majority of the population free from metabolic disease and curious if purchasing this device can actually improve their health and personal performance, let’s take a look at what the research has to say.
folks interested in this device for improved health and longevity could argue it’s crucial to prevent fluctuations in glucose spikes to improve mood and energy, prevent trends in fasting and regular glucose levels to prevent diabetes development, and/or learn what foods work best for you. let’s touch on all of these.
first, glucose fluctuations are completely normal. some foods will spike your glucose more than others, oats are a great example. oats are an excellent staple to a healthy diet as they are rich in whole grains and fiber which can help lower cholesterol. a glucose device may influence you to avoid oats completely since they will spike your blood sugar. instead of avoiding entirely, if you pair oats with a fat (like nuts or chia seeds) you’ll most likely notice a smaller glucose spike due to the slowed rate of digestion from the fats. a quick google search will show you a list of whole foods that spike your blood sugar (candy and soda aside), if you know this you can easily pair these foods with a fat source and minimize your blood sugar spike. if you use a glucose monitoring device you’ll save yourself a google search and will know the exact mmol that your glucose spikes by after eating oats and how quick it drops, but is this information valuable, or is it just more data? I’ll let you decide.
next, looking at trends in your blood glucose on a day by day or hour by hour basis may be slightly overkill, in my opinion of course. your glucose will fluctuate over the course of the day, week and month —totally normal. for example, during the holidays you may have a slightly higher fasting blood glucose level compared to another month like june, ya know, because of all the sweets we eat during the holidays. will this kill you? probably not. should you not enjoy a slice of pie because you want to minimize your glucose spike? definitely not (diabetic and prediabetic folks aside). our body’s are incredible organisms and with that they fluctuate constantly in an effort to maintain homeostasis. because we’re now seeing what’s going on under the hood we can cause unnecessary stress by misinterpreting routine changes our body’s go through as warning signs. when you go to your yearly physical your doctor should test your fasting glucose and interpret the information with you, that data and conversation should give you all the information you need to make appropriate lifestyle and dietary changes. remember, day to day fluctuations are no cause for alarm, negative trends over multiple months is when next steps should be taken if necessary.
lastly, learning what foods work best for you is a completely valid reason to use a glucose monitor. with this device you will absolutely learn what happens in your body when you eat one food over another, and if this helps you move towards a more unprocessed whole food diet then I am all on board. just be careful not to switch from whole to processed foods just to keep your blood sugar from fluctuating, like swapping oats for a a fiber powder. you’ll be much better off adding whole foods (like nuts) to your diet versus replacing whole foods with processed options.
now let’s talk about monitoring glucose for improved athletic performance.
a small subset of clinicians theorize that there are certain blood glucose levels where the body operates at peak performance (there is virtually no evidence for this belief, and even less research on this nichè population as it’s such a small subset and continuous glucose monitors, for healthy populations, are so new).
let’s look into what research there is about this topic.
a study on 7 ultramarathoners found that their glucose concentrations ranged from 61.9 to 252.0 mg/dl across their training and event itself. the runner’s Average glucose concentrations over the entire race ranged from 104 to 164 mg/dl —for reference, normal glucose levels typically range from 70 to 140 mg/dL. researchers also found that Running speeds correlated significantly with glucose concentrations and with energy/carbohydrate intake.
so maybe tracking your glucose levels during a race or workout seems like overkill, but what about the athletes in the previous study who were at the low and high end of the range, that can’t be good, right? surely we’d want insight into that to prevent athletes from spending excessive time in hypo or hyperglycemia.
there is very little information out about consequences stemming from time spent in a hypo or hyperglycemic state. one such unpublished white paper study looked into this very thing and found that among four national elite swedish swimmers three had occurrences of hypoglycemia (below 70 mg/dl). these swimmers were hypoglycemic for 224 minutes per week, which represented 2.59% of the entire week.
less than 3% across an entire week. this is another example that everyone’s body responds differently to glucose and the removal rate varies as well. what we do know is that No study has been reported in the medical literature as to (1) whether an otherwise healthy person with normal glucose tolerance or an elite athlete can use continuous glucose monitors to attain a narrow glucose range generally accepted as peak performance level of glycemia and (2) whether increased time living at such a level indeed improves performance at any task.
with all this said, i am in favor of being informed about your body. it’s definitely good to know what’s going on; but a lot of the new metrics that “are crucial for health” are honestly a load of eye-wash. the right kind of data is great, too much data is useless. whatever decision you decide is right for you and your circumstances, i just hope this article helps provide more education to this topic so you can ultimately make an informed decision off fact and research, not marketing tactics.
i also know no-one asked but i feel unsolicited advice can sometimes be helpful so here’s what I would do if a client of mine asked what they should do to live a healthier life (with or without a glucose monitor).
eat whole foods more than you eat processed food: vegetables, fruits, nuts, seeds, legumes, whole grains, lean protein sources. this doesn’t mean you can never have a candy bar just, on average, eat more of the foods mentioned instead of chips, soda, and cookies. your body responds to averages, no one is perfect, just try and eat the unprocessed option the majority of the time.
exercise. no, you don’t need to run a marathon or make working out your new personality, just move your body and move it consistently — walking, strength training, yoga, biking, whatever you enjoy doing just MOVE. exercise (of all kinds) stimulates insulin secretion and promotes the movement of glut-4 to your cells surface (which, if you remember from earlier, is a glucose transporter that helps bring glucose from the blood into the cells, helping in maintaining a balanced blood glucose level). both of these, insulin availability and increased surface area and external location of glut-4, is a perfect recipe for healthy blood glucose control.
miles is a trainer, speaker, writer, and consultant who specializes in performance and longevity within the health and wellness space. with over ten years of experience, a masters degree in exercise and nutrition science and multiple strength and conditioning certifications miles aims to combine practical application with research to provide actionable strategies for people looking to live longer and excel athletically.
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