Q - Power
30r20 (1 of 3)
Everything you wanted to know about 30r20s
Rowers have been doing 30 minute pieces rate capped at 20 for as long as I can remember, and most rowers are aware of Sir Matthew Pinsent’s 9,009m score at an altitude of some 2,000m.
So what is the reasoning behind doing them? Well, I cannot comment on why others think they are a good idea, but I can certainly set out why here at Q-Power we think they are a good training investment.
We have to go back to the physiological demands of a 2,000m race. We are not going to consider all of them here (such as the heart’s ability to deliver oxygenated blood). Instead we are going to focus on the working muscle. In the race it will be asked to perform about 200 repetitions or thereabouts, producing the largest possible force that can be sustained over that period. The problem is that in attempting this feat, large amounts of lactic acid will be produced which will limit the ability of the muscle to perform.
A very substantial part of the training we do is designed to reduce the amount of lactic acid produced at a given power output, thereby allowing us to work harder. (We can also train to improve the efficiency with which that acid is taken away from the working muscle cells and handled by the body as whole, but we can put that to one side for the moment).
The muscles consist of different fibre types, which can simplistically be described as “fast twitch” and “slow twitch”. There is a bit more to it than that, but it is enough for present purposes. The majority of the energy provided in a 2,000m race is produced aerobically (in fact approximately 80%) and slow twitch fibres have a far greater capacity to work aerobically than their fast twitch counterparts. Whereas slow twitch fibres may be beneficial to rowing, does that mean we cannot derive performance benefit from fast twitch fibers?
The answer to that is that we can still get our fast twitch fibres to meaningfully contribute to the process. To understand the issue we need to consider briefly what is going on in the working muscle.
When glucose is metabolised (being pretty much the only source of energy up at 2k intensity), the molecule is always divided into two identical halves (a process which does not require oxygen) and releasing about 15% of the available energy. These halves are acidic (somewhat simplifying what actually occures). Either the acid accumulates, or it is loaded into the mitochondria which are the engines of the cell. Just add oxygen and the mitochondria will churn out energy, carbon dioxide and water.
Now this is where it starts to get interesting. Even if there is sufficient oxygen available, the cells will not load all of the acid into the mitochondria (which is why you start to accumulate lactic acid in the body below 100% VO2max). Some cells “like” to produce lactic acid, whereas others “like” to load it into the mitochondria. This “desire” to load acid into the mitochondria can be trained.
A major difference between fast twitch fibres and slow twitch fibres is that fast twitch fibres are happy to allow the lactic acid to accumulate. Slow twitch fibres prefer to work aerobically.
Yes, all very interesting, you might say, but what has any of this got to do with 30r20s. Nearly there!
Read more...
