Diabetes and physical activity recommendations. How much is enough?
The department of health describes physical Inactivity as a silent killer. The benefits of physical activity are well known and it is an important part of being healthy and fit.
Exercise can also have a positive impact on blood glucose levels too. When you exercise your body doesn’t need insulin to use the glucose in your blood for energy. Glucose is therefore able to exit the blood and get to the cells independently of insulin. This is true in all types of diabetes and can therefore help reduce blood glucose levels.
In the UK, physical activity levels are dramatically below the recommendations. 26% or over one quarter of adults are inactive and sedentary. This is big numbers in a climate where lifestyle related diseases are on the rise. Particularly type 2 diabetes.
In fairness, once you delve a little deeper into the figures and break them down into age groups, it paints a slightly different picture. Only 15% of people aged 16-24 years old compared to 54% of people aged 75+ are inactive. So you can see how the average can be slightly misleading.
Nonetheless, 15% of 16-24 year olds failing to meet the recommended activity levels is quite significant. Furthermore, many patients I see do not meet the minimum recommendations for physical activity. This can be frustrating because I know how much their conditions could be improved if only they increased their activity levels.
It can be even more frustrating when you actually look at what the recommendations are.
What are the exercise recommendations?
The baseline activity levels for general health are 150 minutes per week of moderate activity, like a brisk walk. This is what the above people are not meeting.
Another way of putting this is you need to do only 30 minutes per day, 5 days per week. This can even can be built up over the day by separating it into chunks.
For this to work though, you need to increase your core temperature. You must feel like you are moving and therefore get a little warmer or sweaty.
You can reduce this number to 75 minutes per week or just over 10 minutes per day if you perform high intensity exercise.
Both should also include resistance training such as weights training or carrying shopping bags on 2 of those days.
In reality most people will do a combination of each. Essentially, the time spent doing activity can come down as intensity goes up and vice versa.
I pulled the following straight from the NHS Choices website (link here) explaining the benefits of meeting the 150 minutes per week:
- up to a 35% lower risk of coronary heart disease and stroke
- up to a 50% lower risk of type 2 diabetes
- up to a 50% lower risk of colon cancer
- up to a 20% lower risk of breast cancer
- a 30% lower risk of early death
- up to an 83% lower risk of osteoarthritis
- up to a 68% lower risk of hip fracture
- a 30% lower risk of falls (among older adults)
- up to a 30% lower risk of depression
- up to a 30% lower risk of dementia
Remember this is doing only the bare minimum recommendations.
Weight gain prevention & maintenance
The recommendations are increased if specific fitness or weight loss is your goal. The National Institute for Health and Care Excellence (NICE) unfortunately make no recommendations for losing weight through physical activity. Instead they focus on preventing obesity and maintaining weight loss.
Without dietary changes, you should aim for 45-60 minutes per day of moderate physical activity to prevent obesity. You may be able to decrease this if dietary changes accompany your activity.
People who have been obese and lost weight need to aim for 60-90 minutes per day of moderate physical activity to prevent weight re-gain. This is only from a physical activity stand point (NICE, 2014).
From personal experience, the thing with exercise or physical activity is the more you can manage the better. This is particularly the case with weight loss.
Blood glucose control
I mentioned in the introduction exercise can help reduce blood glucose levels. The research isn’t conclusive on this in type 1 diabetes but I can speak from experience. Those with type 1 who do exercise tend to have lower glucose levels compared to those who are idle but it can leave them prone to hypo’s. With type 2 diabetes and gestational diabetes, the benefits are more obvious and it does help to reduce glucose levels.
First the theory, why does it help?
Your cells do not need insulin to accept glucose when you exercise. Instead they use receptors called GLUT-4 receptors, which act like mini shuttle buses. The GLUT-4 receptors drive to the glucose and shuttle it back to where it is needed and thus remove it from the blood. This happens because during exercise your muscles need energy quickly.
Insulin, which is usually responsible for getting the glucose into the muscles and liver is used more for storing glucose (known as glycogen) and energy requirements when at rest.
During exercise, the body needs glucose quickly and so does not want insulin telling the liver to store glucose as glycogen but rather release it. Therefore, during exercise insulin production is pretty much stopped and the body uses the GLUT-4 receptors to get it’s glucose fix.
If you’re taking insulin or sulphonylureas please be aware that these medications plus exercise can leave you prone to hypo’s. This is because your body can’t switch off the medications once taken and therefore they need to just run their course. Add exercise to this and you get a double effect of two variables trying to reduce your glucose levels at the same time. If you find you hypo frequently around exercise it may be worth speaking with your diabetes team about how to reduce your medications around exercise.
Cause for concern
Fair enough if the recommendations were for 2 hour gym sessions each day. However, they are actually pretty achievable.
I’m not usually one to give the motivational pep talks in my blogs as I like to remain objective. However, I calculated how many minutes there are in a week and compared it to the physical activity guidelines. The results are quite staggering.
There are 10,080 minutes in a week. The recommendations are between 75-150 minutes per week. That works out as 0.7-1.4% of the total week. Don’t forget, physical activity doesn’t necessarily need dedicated time set aside to do it as it can be built into everyday life.
What worries me though isn’t just the fact 26% of people do not meet the minimum requirements of 75-150 minutes per week. Rather, the many people who meet the minimum requirement but just barely. I’ve been unable to find data on the number of people achieving at least an hour or above per day but it would be an interesting read.
150 minutes of brisk walking does not burn up many calories and therefore as a weight loss tool, it is pretty ineffective. Therefore, even if you meet the minimum requirements, you are still prone to weight gain. In order, to lose weight from activity alone, you need to go above and beyond. This is particularly relevant in type 2 diabetes because the vast majority of cases are brought about due to weight gain.
When it’s not appropriate to meet guidelines
Some patients I see have very valid reasons why they cannot meet the recommendations due to health reasons. Often this is due to health or mobility reasons and often these patients can struggle with their weight also.
Patients unable to mobilise shouldn’t over do it and unfortunately have to do the best with the hand they have been dealt. Unlike poker though, you cannot bluff and still get results. In these patients, the majority of lifestyle change needs to come from diet. Especially in those patients who are prone to weight gain as a result of their low calorie expenditure.
If you can continue to exercise then this is something you should aim to do. Perhaps knee pain prevents you from walking far but you are still able to swim, use upper body equipment at the gym, or join a specific exercise group. For most people there generally remains a way of overcoming specific problems but I appreciate in some people activity is very problematic.
All physical programmes need to match your current fitness level. Don’t over do it too soon and build up gradually. So maybe don’t start lacing up the ultra marathon shoes just yet but aim to build up.
Great resources include couch to 5km (click link) which can also be downloaded as an app. It provides a training plan which is easy to follow and builds you up gradually. Otherwise, there are many events where you can sign up with friends in order to increase your activity levels and even raise money for good causes. MacMillan and Race for Life are just two organisations that regularly have events running throughout the year.
Physical activity doesn’t have to be any of these though. Integrate it into your everyday life. Walk short journeys, park further away from destinations, walk up and down the stairs twice etc. It can really be that simple.