I came across this on-line news story. It concerns a study done in individuals with ‘impaired glucose tolerance’ (essentially, individuals who do not handle glucose well in the body but are not impaired enough to be classed a diabetic. The report (and other reports) say the study was published today (4th January) in the journal Diabetes Care, but I can’t find any trace of this study around now. I did, however, find this study [1] which the reports appear to be referring to which was published back in print in August (and on-line in July).
In this study, 87 adults with impaired glucose tolerance were managed with one of three strategies:
1. The provision of a short information leaflet about impaired glucose tolerance
2. The provision of a three-hour seminar about impaired glucose tolerance (focusing on things like cause and the potential benefits of exercise)
3. The provision of the same three-hour seminar about diabetes, plus a pedometer (that counts steps) as well as a step-per-day target.
(Sedentary individuals were encouraged to increase their activity levels by at least 3,000 steps per day, equivalent to about 30 minutes of walking. Those achieving >6,000 steps per day were encouraged to try to reach at least 9,000 steps per day, an amount that is likely to include 30 min of walking activity in addition to usual daily activity. Those achieving >9,000 steps per day were encouraged to at least maintain their current activity levels and were informed that health benefits could be achieved by increasing their activity levels further).
After a year, individuals had their fasting glucose levels measured, as well as their glucose levels after a ‘load’ of glucose was given to them. Compared to those who got just a leaflet (the ‘control’ group), those who got the three-hour seminar (without pedometer and stepping target) saw no improvement in their biochemical parameters. However, those who got the seminar, and pedometer, and stepping target did.
Those who used the pedometer saw their blood sugar levels fall by about 15 per cent. If this benefit were sustained, it would be expected to reduce risk of developing type 2 diabetes by about half, according to the authors of the study.
For a long time I have been a fan of walking, partly because of the evidence linking this activity with benefits for mental and physical health and well-being. I also like walking because it can be done by just about anyone (including those that do not consider themselves ‘sporty’), does not require much in the way of special equipment (so appropriate foot-ware is a good idea), and tends not to induce much in the way of injury (unlike more vigorous activities such as running).
This results of this study showed that those who got a pedometer and a ‘stepping target’ did actually end up significantly more active, even after one year. Which suggests that a pedometer might be a worthwhile investment for those seeking to step up (excuse the pun) their activity this year, and in future years.
By the way, this research is not the only research which links pedometer use with increased activity. See here for research from a couple of years ago which summarises the findings of several relevant studies.
References:
1. Yates T, et al. Effectiveness of a pragmatic education program designed to promote walking activity in individuals with impaired glucose tolerance: a randomized controlled trial. Diabetes Care 2009;32(8):1404-10
To be honest, if I had to choose between taking 1 gelcap of Vitamin D3 5,000iu/day (costing 3p) or walking 3,000, 6,000 or 9,000 steps/day, I would always choose the former. From Vitamin D:-
“An Oral Glucose Tolerance Test in September 2008 showed that I had absolutely normal Glucose Tolerance (2 hours post-glucose load serum glucose = 3.7mmol/L) whereas in 2003 I had moderately impaired Glucose Tolerance (2 hours post-glucose load serum glucose = 8.7mmol/L).”
Dr John, this will be familiar stuff to you but I want to be certain I have this clear in lay terms.
The body has a system to manage energy being the metabolism. There are several pathways within the metabolism used to manage energy, be that burn it, sequester (save) it for use later, or release it from storage. The metabolism extends to real time energy management, short term, and long term storage.
Short term storage is akin to a buffer or a ‘sink’ which is intended to cope with the excess of energy following a meal and release it later in the normal course of periodicity between eating meals. The nature of the buffer is the capacity to store energy rich glycogen in the muscles and liver, I believe, but for this to work there is the imperative for the stored glycogen to be depleted between meals.
Reasoning then suggests that large portion sizes and/or inadequate levels of activity between meals fails to deplete the buffer and therefore negates its’ effectiveness to cope with the next meal and comparable to filling a washbasin without having emptied the contents arising from the previous use. So this research is a pertinent reminder to empty the washbasin, so to speak, after use.
The clever bit is in attaining a functional understanding of how and why. If the short term buffer is full then I can see increased likelihood of the next meal being directed to deposition as fat via alternate metabolic pathways for no more complicated reason than the appropriate pathway being ‘closed’ with a ‘no-vacancies’ sign hanging from the door at its’ end.
Exercise would clearly consume and deplete muscle glycogen to restore normal service but exercise also improves glucose tolerance. It’s a topic that interests me. Can you offer some direction as to how a layperson can comprehend how GT is improved?
Can I deplete glycogen reserves while thinking?
I agree, a pedometer is a great and simple way to record activity levels. The activity can be intentional, as in deliberately going for a walk, or be intrinsic to the normal business of life. I think increasing the latter is under-rated.
I like the attention given to vitamin D but as a comment on Nigepoos post might I inquire if a multilateral approach may have merit over a unilateral one?
Doing both is probably better than doing one. However, I can’t walk around & surf the internet at the same time and I know which activity I’d much rather be doing!
Is not walking 1,000s of steps every day really that bad? In Paleo times, women of child-bearing age would have stayed at “home” to look after the children rather than walking around gathering stuff.
Chris,
Your glycogen stores provide energy for physical exercise and thinking. The harder you exercise or think for that matter the more glycogen you will use up. Hard exercsie will use up alot more glycogen than deep thought however.
You are right that if your glycogen reserves are full then you will tend to deposit your last meal as fat. What happens if you exercise both hard and often (as I do), is that your glycogen reserves are depleted and your body uses the last meal to top it up.
The whole topic of metabolism is part of biochemistry and if you can find a layman’s guide to it you may find that useful.