iPhone photo from my walk with Sophie 2 days ago.
The date may seem a little bit early but the closer it comes to Christmas the less likely it is that we can collect the whole bunch here at our favorite Italian restaurant and, the more jammed do the restaurants get all over the place. Tonight 19 of us working on the various biestmilch projects meet to let the year pass by once again and have some fun.
I found this post on my favorite sport blog »the Science of Sport«. The results of the 2 studies cited in this post from Jonathan Dugas and Ross Tucker are very much in line with our biestmilch philosophy.
In the 2004 study, cyclists had to complete a given amount of work in as fast a time as possible. This is important to note, because the mode of performance trial can influence the conclusions drawn quite substantially. In both these studies, the cyclists were able to freely select their work-rate and slow down or speed up in response to the swishing around of the carbohydrate drink or the water.
The rinsing with the malto-dextrin solution improved performance by almost 3%. The immediate question arising is of course: Could this really be a metabolic effect?
The usual thinking would be that glucose is superior because it is rapidly metabolised, converted to energy, and delays the onset of fatigue. This study clearly challenges that, for a number of reasons.
1.
The performance trial is quite short. The theory that glucose ingestion has a profound effect on performance is particularly true for long-duration exercise, where the depletion of liver or muscle glycogen may be possible.
There is some evidence that glucose ingestion improves performance even during much shorter exercise trials, which is difficult to explain because only a small part of your energy comes from that ingested glucose when you do shorter, high intensity training – that was one of the reasons this study was done in the first place.
2.
In this study, the performance of the cyclists was better on carbohydrates from the very first quarter of the trial. So when performance is broken down, it turns out that you go faster within the first few seconds, and that clearly has nothing to do with metabolic effects.
3.
Another important point is that the malto-dextrin solution was chosen because it is colourless and non-sweet, which means it’s less likely to be obvious to the subjects when they’re on it – this would otherwise introduce the possibility of a large placebo effect.
It turns out that some subjects did pick up the difference: Four of the nine cyclists guessed they were on the carbohydrates-trial, based on taste and viscosity. Of these four, three improved, one did worse. The placebo effect can never be ruled out, but it does seem to have been controlled as much as possible in the study.
Increased central drive – feedback from the mouth, output to the muscles?
So what then is the explanation? This study did not show that rinsing the mouth is better than swallowing the solution. It simply compared rinsing with carbohydrates to rinsing with water. It therefore does not indicate that you should not drink glucose-containing drinks during exercise!
However, what the study does is to help us understand how shorter exercise might be improved by carbohydrates. The authors of this study speculated that there are receptors in the mouth, which are stimulated by the cyrbohydrate-drink (but not by water), and then trigger centers in the brain that then increase the central drive for exercise.
Noakes and co-workers, (Tucker and Dugas made their PhD at Noakes’ department at Cape Town University) did a lot of research on fatigue as phenomenon of the central nervous system and not the muscles. They introduced more dynamic explanatory models into sport. According to their view it is the brain (central governor) that regulates performance by controlling muscle activation in response to various cues like heat, oxygen availability etc. This carbohydrate-finding would fit in with that kind of thinking – the brain receives information from the mouth that glucose is available and it allows an increase in muscle activation. For further explanation read the Fatigue Series
The sun rises at 8:15 and turns the landscape into a beautiful graphical pattern.
graphical pattern designed by nature
Lonely Christmas tree by the lake, close by our office in Austria.
One week ago Yvonne signed an agreement with Biestmilch Seven. Yvonne is an outstanding athlete holding the women’s triathlon world record on the long distance. In Hawaii she crossed the finishline in second place behind Chrissie Wellington.
Yvonne van Vlerken
The pencils have been Biestmilch’s first give-away. Since then the pencils draw the biest’s gentle path into the most different territories.
Headphones
Biest in the wall
Biest in supportive role
Source: Herwig Steiner, Biestmilch team member with many talents
