Monday, February 8, 2010

Slow-mo a go go

A new tack for building up speed - running for a heart rate

I am now back on Interurban running on the flat and level. I came across a intense dissertation on target heart rate and exactly why running slow builds speed. It makes sense on a cellular level and since I have a marathon coming up in 4 months I thought it was worth 6 weeks of my time to note improvement. Maintaining a heart rate within 5 bpm (130-135) is not easy - for the first few minutes it is impossible as there is a certain hysteresis as your heart gets used to new demands. So far 130-135 is approx 4.4 mph = a very slow jog, more of a shuffle.

Pulse and breathing

At first the relationship between pulse and breathing seems rather elementary. When your pulse is fast you breathe harder and faster. This is a truth, but the corollary would be that if you breath hard your pulse should race. This is not true. which leads us to the reasons behind breath technique. Breath technique comes a close second to running technique. For a given pace if you focus on breathing more deeply and quickly your pulse will drop. When you think about it it makes sense - the reason why your heart beat increases is due to your muscles request for more oxygen. Your body does not care if your heart is beating fast or slow as long as it gets the oxygen it needs to metabolize nutrients to power the efforts of your muscles. Your heart rate can be an indicator of how efficient the process is. and that leads us to a discussion on the scale of the metaboli-meter...

The heart-o-meter

There have been various articles covering running and training and the opinions all focused on "target heart rate" which is established by the apparently arbitrary calculation available everywhere on the web.
While I took this number as the rate I was to shoot for, I did not know the reasoning behind it. After a modicum of research I believe I've found an answer that makes sense. When your exercise, you move your body by contracting and releasing muscles. To do this your muscles require oxygen and nutrients. Now we must talk metabolism and how your heart rate can be used as a meter to tell you how your body is doing

Cellular communications - your muscles saying "Can you hear me now?"

Mitochondria within the cells provides the cells with energy by metabolizing the oxygen and nutrients (glycogen). When you are exercising aerobically, the mitochondria can keep up with demand, and will actually increase in the cell. However when our muscle use exceeds the ability of the mitochondria to produce energy the cells will excrete lactic acid and shut down. This happens over a period of time and is commonly referred to as "THE WALL" as your cells shut down one by one, your body will slow down. and during that time your cells are shut down, they are not growing mitochondria. Lactic acid build up in the muscles is what causes the day after soreness - it is not all bad, and has it's place in the workout regime.

Intense Relationships

Mitochondria feed your cells, exercising at a rate that the mitochondria can keep up with increases the amount of mitochondria in the cells. With a higher level of mitochondria, your muscles can work harder. Are you picking up what I'm laying down???
Exercise at a higher rate than the mitochondria can keep up with is termed "Anaerobic" and has it's place in exercise - it strengthens the muscles and increases the amount of short term work a muscle can do. However maximizing your mitochondria has a much higher value for distance runners as it allows you to feed your muscles more efficiently and allows you to increase both pace and endurance.

Now, what about that heart-o-meter??

I'll quote the trainer's blog for this so as to capture the thought completely

"As a general guide, and in my experience, this is what I have found works best. Marathon HR will be approx 15-20 beats lower than HRmax (no better). And aerobic conditioning HR needs to be another 30 bpm below THAT (and hence ~50bpm below HRmax) "

That's the theory I'm working on now, maintaining 130-135 heart rate and hoping that over time my pace picks up ( before the marathon, June 5th!)

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