We’re living on the run – so snacking is a cultural norm. Snacking is seldom GOOD FOR YOU, but exercise snacking is the exception, so go on, indulge yourself….
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How to use exercise to keep your sugar levels in-check
Dinner time !
Growing up, this was the cue to abandon what you were doing, head for the bathroom to you’re your hands. My caregivers worked hard at programming the
“Wash your hands before dinner behaviour”
This two minute exercise is designed to avoid unwelcome bacterial guests and bits of dirt, joining the dinner table.
Dinner time habits
Hopefully it’s not a routine you’ve completely abandoned, now that you are all grown up. Although let’s be honest, most of the time, the bacteria living on your keyboard/phone are potentially a lot less hazardous to your health than the pond critters.
Actually probably not – soil bacteria are the good guys.
The creatures on your phone and laptop are human commensals-cum-pathogens. Who is there will depend on where your phone has recently been. If that includes scrolling the gram in the bathroom…… it might not be that “healthful”. Lol !
But we’re not talking microflora today, we’re talking dinner time habits.
Introducing exercise snacking
Science suggest it might be time to add a new pre-dinner activity to your routine…..
It makes biological sense and there is plenty of evidence, it can make a difference to glycaemic control. Let’s start with the evidence….
The value of exercise snacking
One of the first groups of researchers to study the value of exercise snacking, was a team based at the University of Otago. They put 9 rather tubby individuals, who were insulin resistant, on an “exercise” regimen.
The protocol went on for several days, but the day that WE are interested in is DAY 3.
This is the day when the EXERCISING HAPPENED. Everyone had an opportunity to do one of each of the “regimens”. There were actually three regimens explored, but to simplify things, I’m only sharing two : the continuous and exercise snack.
The exercise prescription
The CONTINUOUS/CONTROL regimen
This is what you are being told to do. It was a standard exercise session and involved a 30 minute moderate intensity (60 % of maximal heart rate) work-out on a tread-mill.
The EXERCISE SNACKING regimen
This involved six 1 minute bursts of intense activity on the treadmill. Participants had to get their heart thumping like a race-horse i.e. they had to reach 90 % of their maximal heart rate, for the 1 minute. Following the “torture”, they were allowed to rest for a minute, before the next big push. Resting did not involve sitting down, they kept going on the treadmill at a more comfortable pace.
NOTE : Health gurus would refer the EXERCISE SNACKING regimen as HIT (high intensity interval training).
Timing of the exercise pill
The continuous exercise session, equates with the guy, who stops at the gym on the way home from work for a work out and when he/she is done, goes for dinner. The exercise snacks, happened 30 minutes before breakfast, lunch and supper.
For the curious, below is breakdown of the meals.
When all was said and done, the exercise programmes were “identical” in terms length, the difference was in the when the exercising sessions happened.
The benefits …
Here is the mean glucose concentration of the participants throughout the day.
At first glance it’s pretty obvious. The exercise snackers (represented by the blue line) had lower sugar peaks following all three meals and their sugar levels returned to baseline more quickly. Remarkably, the 10 minutes of exercise, packed the same punch as the 30 minute session – highlighting that SHORT & HARD, is as beneficial as LONG.
This is good news if you are time constrained….
It’s not a big surprise
Exercise requires muscles to fuel up – so as expected, the exercise sessions improved sugar levels post-prandially i.e. after the meal.
The interesting finding…..
Exercise snacking did a better job at keeping the sugar levels in check overall.
And as a rule, lower sugar levels, create BETTER BODY CHEMISTRY and WOW-ZA, all this happens in less time….
Why does it work ?
Muscles are big glucose consumers all the time, but especially when they’re exercising. Now it turns out, that bulk imports of glucose, into muscle cells, depends on the GLUT4 gates being up.
The trouble is, the default location of these gates is deep inside the cell.
They’re actually tethered down, only when “the appropriate signal” is given, are they translocated to the surface, to facilitate glucose uptake.
Insulin the gate keeper
Unfortunately insulin gives the signal, which means when you are insulin resistant the gates are stuck inside i.e. they are not where they’re meant to be, when they are meant to be there. Eish !
Now they do eventually make it to the surface, but their arrival is delayed.
It’s the delay, that is a big part of the trouble in the metabolically challenged.
The mucking about, allows the sugar levels to remain high, for longer than they should and contributes to bad body chemistry.
Now insulin is one of the triggers to mobilize the GLUT4 gate, but he doesn’t actually cut the cord, he just issues instructions – but insulin is not the only trigger.
Hungry muscles kick the gates down
When muscles are contracting, they initiate a cascade of chemical signals, which see calcium levels sky rocket, inside the muscle fibers, this signalling facilities is also able to snip those cords…….
So GLUT4 gates end up at the surface.
NOTE : To be perfectly honest, the distribution is a little bit different, but this difference is not an issue, it works.
Bulk glucose imports happen effortlessly….
It’s all in the timing
By exercising, just before eating a carb heavy snack, you’re able to get the gates up EFFICIENTLY.
And it is this efficiency that saves the day.
Because it means that any glucose being consumed, which makes it past the gate keepers in the digestive tract and into the circulation, it is able to IMMEDIATELY enter the muscle cells.
There is no hanging around, until the pancreas/liver get their act together.
Of course, what happens when the sugar gets inside, is a little different. A loss less of it will be burned, while a lot more will be stored, in the form of glycogen.
But, the point is…. the circulating glucose is not dependent on the body’s compromised insulin responses.
It goes in.
The post-prandial sugar spike is lower.
Both in the moment and for hours thereafter…….
In the table above, you can see the average glucose levels, before, on the day of the exercise and the day after. The exercise snacking benefits were still in play the next day.
Putting away the GLUT4 gates is slower
When a muscle stops contracting – the biochemistry changes QUICKLY, in a jiffy, calcium levels return to normal, but despite these rapid adjustments, the GLUT4 gates don’t immediately drop back down.
Putting them away is a slow drawn out process.
Mice studies suggest it can take as long as 130 min to pack them all away.
And this is GOOD NEWS, it means, muscles will continue to import glucose a wee bit longer than “normal”, providing glycemic benefits, beyond just the post prandial window, which in the metabolically healthy is done and dusted at 90 minutes.
And it’s the perfect solution for the time constrained metabolically challenged.
Exercise for busy people
It is often difficult to schedule BIG exercise sessions into a very busy day. And a BIG exercise session at the gym, although beneficial, can still leave you with lots of “sitting on your butt” time.
Squeezing in a 10 minute exercise snack, between things, is much more do-able.
And, potentially more beneficial.
Have an exercise snack
So grab a skipping rope and hop to it. Hop for a minute, take a short breather. Rinse and repeat.
Not co-ordinated enough to avoid getting tangled in the skipping rope. Try a few
- jumping jacks
- run on the spot (aim to keep your knees high)
If cardiovascular fitness isn’t your jam, LIFT SOMETHING HEAVY a couple of times.
The type of exercise you’re looking for, is something that is “exhausting”, you want to do it until you’re “exhausted” i.e. you can’t anymore. Then see if you can do it once or twice again, until you are “exhausted” – only then call it quits.
Exhaust yourself and WIN
We’re living on the run – so snacking is a cultural norm. Snacking is seldom GOOD FOR YOU, but exercise snacking is the exception, so go on, indulge yourself…………
For more ideas on how to minimize those sugar spikes at dinner time, head on over to the “Suppressing sugar spikes” library page.
Kinetics of contraction-induced GLUT4 translocation in skeletal muscle fibers from living mice. Diabetes (2010) 59:2134–2144. Hans P.M.M. Lauritzen, Henrik Galbo, Taro Toyoda, and Laurie J. Goodyear
Insulin- and Contraction-Induced Glucose Transporter 4 Traffic in Muscle: Insights From a Novel Imaging Approach. Exerc. Sport Sci. Rev. (2013) Vol. 41 (2) : 77Y86. Hans P.M.M. Lauritzen.
When you’re insulin resistant, sugar can’t leave the blood, because the glucose gates, normally used by the sugar molecules, are missing. Gate moving needs…
If you’re metabolically challenged, late afternoon exercise, will give you MORE bang for your buck, in terms of health benefits.
Modern hunter-gatherers don’t move more than the average Westerner – so lack of energy expenditure is not to blame for modern man’s weight problems.