Running Hurts

I’ve got it in my head that I want to be a runner. I’ve tried this experiment a couple of times and at one point long ago ran a 5k in just under 25 minutes.

I bought some new shoes because the padding in my 993’s was shot and hit the proverbial bricks. Ouch…running hurts. I was pretty disappointed after these results:

A little under two miles in 25 minutes sort of sucks. In my defense this is the first time I’ve tried to run in over a year.

Last night I went out with the Garmin again and turned in similarly pathetic results:

Now, here’s where it gets interesting. If you look at the timing I suck, if you dig a little deeper then maybe I’m not so bad.

My average heart rate for 25 minutes of running and walking was 130 bpm. If you look at the chart you can see the little peaks that correspond to the peaks in speed. The slower speeds are when I was walking, higher speeds are running obviously. Here’s the interesting part. If you go back and look at Sunday Afternoon Ride you can see my average heart rate is 156 over the course of an hour. There are still peaks and valleys or times of exertion and rest. My point is that my cardiovascular health is such that I can maintain 85% of my maximum heart rate for an hour except when I’m running.

In summary, my excuse is that my problem is leg strength or more specifically muscle memory. Here’s what wikipedia has to say:

When participating in any sport, new motor skills and movement combinations are frequently being used and repeated. All sports require some degree of strength, endurance training and skilled reaching, in order to be successful in the required tasks.

Evidence has shown that increases in strength occur well before muscle hypertrophy, and decreases in strength due to detraining or ceasing to repeat the exercise over an extended period of time precede muscle atrophy.[13] Specifically, strength training enhances motor neuron excitability and induces synaptogenesis, both of which would help in enhancing communication between the nervous system and the muscles themselves.[13].

However, neuromuscular efficacy is not altered within a 2 week time period following cessation of the muscle usage; instead it is merely the neuron`s ability to excite the muscle that declines in correlation with the muscle`s decrease in strength.[14] This confirms that muscle strength is first influenced by the inner neural circuitry, rather than by external physiological changes in the muscle size.

Reorganization of motor maps within the cortex are not altered in either strength or endurance training. However, within the motor cortex, endurance induces angiogenesis within as little as 3 weeks to increase blood flow to the involved regions.[13] In addition, neurotropic factors within the motor cortex are upregulated in response to endurance training to promote neural survival.[13]

Skilled motor tasks have been divided into two distinct phases; a fast learning phase, in which an optimal plan for performance is established, and a slow learning phase, in which longer term structural modifications are made on specific motor modules.[15] Even a small amount of training may be enough to induce neural processes that continue to evolve even after the training has stopped, which provides a potential basis for consolidation of the task. Additionally, studying mice while they are learning a new complex reaching task, has found that “motor learning leads to rapid formation of dendritic spines (spinogenesis) in the motor cortex contralateral to the reaching forelimb”.[16] However, motor cortex reorganization itself does not occur at a uniform rate across training periods. It has been suggested that the synaptogenesis and motor map reorganization merely represent the consolidation, and not the acquisition itself, of a specific motor task.[17] Furthermore, the degree of plasticity in various locations (namely motor cortex versus spinal cord) is dependent on the behavioural demands and nature of the task (i.e. skilled reaching versus strength training).[13]

Whether strength or endurance related, it is plausible that the majority of motor movements would require a skilled moving task of some form, whether it be maintaining proper form when paddling a canoe, or bench pressing a heavier weight. Endurance training assists the formation of these new neural representations within the motor cortex by up regulating neurotropic factors that could enhance the survival of the newer neural maps formed due to the skilled movement training.[13] Strength training results are seen in the spinal cord well before any physiological muscular adaptation is established through muscle hypertrophy or atrophy.[13] The results of endurance and strength training, and skilled reaching, therefore combine to help each other maximize performance output.