Light Weight Trainers and Neuromuscular Transmitters

[oldstyle]

There have been a lot of questions recently about the benefits if any of running in light weight trainers. I'll give plus reps to any and all who can connect the dots between light weight trainers and neuromuscular transmitters. Coaches please hold your answers and opinions for a while. Lets see what the H.S. and College runners have to say.

[S.E.B.runner]

Light weight trainers are generally more flexible and with a lower heel height. This means that the foot (the arch in particular) is allowed to flex more by the shoe, so the muscles in the foot have to make up for the lack of support. The way the muscles 'know' this is that they have nerves in them which allow proprioception/ kinesthesia- the ability to sense the position of the different parts of the body (here, in particular the foot).
The muscles have stretch receptors in them, and being heavily supported and cushioned by an inflexible shoe would reduce the range and speed of motion of the muscle, so these receptors would be less stimulated. Added to this is the reduced ability to feel the variation in the surface of the road (with thin shoes or no shoes any small bumps can be detected by pressure on the sole of the foot, making muscles work more to position/cushion the foot but cushioning in a shoe reduces this).
As for the link to the transmitter, when a receptor is stimulated it causes the release of a chemical that initiates the nerve impulse. I imagine the 'neuromuscular transmitter' itself would be something like acetylcholine (though as a high-shcooler who quit biology 2 years ago my memory of this may be a bit hazy:)).

[oldstyle]

Light weight trainers are generally more flexible and with a lower heel height. This means that the foot (the arch in particular) is allowed to flex more by the shoe, so the muscles in the foot have to make up for the lack of support. The way the muscles 'know' this is that they have nerves in them which allow proprioception/ kinesthesia- the ability to sense the position of the different parts of the body (here, in particular the foot).
The muscles have stretch receptors in them, and being heavily supported and cushioned by an inflexible shoe would reduce the range and speed of motion of the muscle, so these receptors would be less stimulated. Added to this is the reduced ability to feel the variation in the surface of the road (with thin shoes or no shoes any small bumps can be detected by pressure on the sole of the foot, making muscles work more to position/cushion the foot but cushioning in a shoe reduces this).
As for the link to the transmitter, when a receptor is stimulated it causes the release of a chemical that initiates the nerve impulse. I imagine the 'neuromuscular transmitter' itself would be something like acetylcholine (though as a high-shcooler who quit biology 2 years ago my memory of this may be a bit hazy:)).
Not the answer I was looking for, but a very informative reply! You earn a + rep. for effort.

[B Hark]

Because the shoes are lighter, the whole kinetic chain of your leg is lighter. So you'll lift legs more, recruiting more motor units (neuron and the muscle fibers it innervates), a more complete percentage of the range of motion is being utilized. The more motor units that are recruited, the more that can see training adaptations. If you don't recruit them they wont get better.

A single neurotransmitter does not control a large muscle's (aka hamstrings, and quads) so in order to see a better training adaptations more motor units have to be recruited.

[oldstyle]

Because the shoes are lighter, the whole kinetic chain of your leg is lighter. So you'll lift legs more, recruiting more motor units (neuron and the muscle fibers it innervates), a more complete percentage of the range of motion is being utilized. The more motor units that are recruited, the more that can see training adaptations. If you don't recruit them they wont get better.

A single neurotransmitter does not control a large muscle's (aka hamstrings, and quads) so in order to see a better training adaptations more motor units have to be recruited.

Ding! Ding! Ding! We Have A Winner!

The research paper I originally read said something to the effect that your central nervous system needs to be trained just like any other pathway. After all it's your electrical system that fires your muscles. So the lighter your shoes are the faster your turnover will be and your central nervous system will adapt. Kind of like muscle memory. It's been a few years since I've read the report. I think it was Running Research News or Peak Performance Sports. Anyway, Good Job B Hark! 1 + rep. on the way!

[luv2run]

. So the lighter your shoes are the faster your turnover will beNot necessarily true, especially not at normal training paces. But you're on the right track.

When you run, you're training your muscles how to fire, how much power to put out and in what way.

You might not move your legs any slower or with less range of motion when wearing heavier shoes. It's hard to tell, since runners adapt to the shoes they're wearing. BUT you will be putting out more force on takeoff and absorbing less on landing, which trains your muscles (or the neuromuscular signals from your brain if you prefer) to fire a certain way.

The more dissimilar your training shoes to your racing shoes, the less practice your muscles have at pushing off with the exact power/force that they will in the race. Wearing lighter shoes will help you adapt/get used to that, but that doesn't mean from a neuromuscular signalling standpoint that it's necessary to wear light shoes every run. Only on intervals near/above race pace might be plenty to get your CNS used to sending those signals.


If you want to train your central nervous system to fire faster or increase maximum turnover, I recommend barefoot strides. If you want increased range of motion, stretch. Running at 7-8 minute pace will probably not improve either of these no matter what's on your feet.


P.S. I prefer light trainers. But mainly because they strengthen small stabilizer/absorbing muscles, not really because of neuromuscular benefits.

[oldstyle]

Not necessarily true, especially not at normal training paces. But you're on the right track.

When you run, you're training your muscles how to fire, how much power to put out and in what way.

You might not move your legs any slower or with less range of motion when wearing heavier shoes. It's hard to tell, since runners adapt to the shoes they're wearing. BUT you will be putting out more force on takeoff and absorbing less on landing, which trains your muscles (or the neuromuscular signals from your brain if you prefer) to fire a certain way.

The more dissimilar your training shoes to your racing shoes, the less practice your muscles have at pushing off with the exact power/force that they will in the race. Wearing lighter shoes will help you adapt/get used to that, but that doesn't mean from a neuromuscular signalling standpoint that it's necessary to wear light shoes every run. Only on intervals near/above race pace might be plenty to get your CNS used to sending those signals.


If you want to train your central nervous system to fire faster or increase maximum turnover, I recommend barefoot strides. If you want increased range of motion, stretch. Running at 7-8 minute pace will probably not improve either of these no matter what's on your feet.


P.S. I prefer light trainers. But mainly because they strengthen small stabilizer/absorbing muscles, not really because of neuromuscular benefits.
I agree with you that it is not necessary to run in LWT's every day. This thread was started because of questions about the benefits of running in LWT's and I was curious to find out what runners knew about what they are doing.
Not meaning to be argumentative but I disagree with you on your point of adapting to the shoes you are wearing. Using myself as a guinea pig I've experimented with trainers and LWT's on daily runs. Over the summer I rotated shoes every other day. Running 6-8 miles on the same course times are faster at the perceived effort level in LWT's by :15-:20 at the beginning, :30's in the middle and a full minute the last mile. Just my opinion but carrying less weight on your feet (in my case 7 oz.) seems to improve speed.

[Father Russia]

I don't think anyone would say that there is a significant benefit or detriment. Slightly improved contractual efficiency probably is second to the raw, mental advantage of running in spikes.

[luv2run]

I agree with you that it is not necessary to run in LWT's every day. This thread was started because of questions about the benefits of running in LWT's and I was curious to find out what runners knew about what they are doing.
Not meaning to be argumentative but I disagree with you on your point of adapting to the shoes you are wearing. Using myself as a guinea pig I've experimented with trainers and LWT's on daily runs. Over the summer I rotated shoes every other day. Running 6-8 miles on the same course times are faster at the perceived effort level in LWT's by :15-:20 at the beginning, :30's in the middle and a full minute the last mile. Just my opinion but carrying less weight on your feet (in my case 7 oz.) seems to improve speed.Oh yeah, I definitely agree that your training runs will be quicker in lighter trainers. I'm just not sure that that'll improve top end speed or make you any quicker in a race.

On the other hand, it makes less sense to me to put extra weight on your feet. So I'd still go with the light trainers.