T -203 - Cadence

As I finish 2nd lunch or early supper I've been thinking a bit about cadence and had a look on the internet for a bit more about it.

Cadence is the speed at which your legs push the pedals or hit the ground each minute. When your running your speed is your stride length times your cadence. So if you stride length is 100cm and your cadence is 80spm (strides per minute) you'll be running 80m per minute or just under 10km/h. Increasing your running speed means either longer strides or more steps. Longer trides are good - think of all those long legged runners - but the further ahead of the body the foot lands the greater the breaking effect - bad news.

Increasing cadence is thus a good way of increasing speed. The other advantage that it gives is that because strides are shorter - stride time with cadence of 80spm is about 12% shorter than with a cadence of 70spm. This means that the muscles are contracting for less time. Interesting/ Not really you say - but here is the rub. Shorter time of muscular effort means less lactic acid build up which all other things being equal means you can run further and faster for less energy.

The downside is that it is difficult to change you running cadence and needs sustained hardwork. Just think of all those drills that you do when swiming to improve your stroke. You also have to do them running. Hah ha ha ha.

Pretty simple really though. At the moment during my base training I'm doing strides in most foundation run sessions. What do I mean by strides - well basically I try to increase my cadence as high as possible. I see how fast I can do thrity right foot landings - but I don't try and run faster. I go a lot faster though.

Looking at the metrics this morning I took my cadence up from 85 to 110spm for 30 strides and saw my heart rate increase by 20bpm but at the same time my speed went up from 10km/h to 20 km/h. If this is a constant ratio a 30% increase in cadence doubles speed. :) Ok if I'd maintained that I'd be anaerobic pretty quickly but you can see the effect.

you can see the metrics here http://connect.garmin.com/activity/514740 and I did the strides at about the 10 minute mark

Trifuel http://www.trifuel.com/triathlon/run/improving-run-cadence-strides-and-plyometrics-001250.php gives this cadence improving drill.

run 10 minutes to warm up and end at a field where you can do your drills.
one leg hops 20-30 times (for distance)
two leg hops 20-30 times (for distance)
one leg hops 20-30 times (for height)
two leg hops 20-30 times (for height)
6x100 yd skipping for distance (walk back to the start)
6x100 yd skipping for height (walk back to the start)
jump rope 10 minutes
run 8x100 yds quickly, walk back to the start

Another useful site is the British Airforce Triathlon team http://www.raf.mod.uk/raftriathlon/rafcms/mediafiles/498B1498_1143_D71E_469F6513AD1643D5.pdf which discusses cadence whilst running and cycling in a lot more detail.