Encounter

Friday, July 06, 2007

After yesterday's NCAP Technical Level 1 lecture by coach, I'm reminded of one of the benefits of riding wash/doing doubles: It allows you to develop your technique for paddling at higher frequencies at higher speeds. Paddling technique is very much a matter of coordination between the brain and the body, and it is only improved through practice. As much as increasing strength allows one to increase paddling cycles, this increased paddling cycle / frequency itself requires a higher level of coordination than before. Therefore, wash riding (more possibly stern wash) and doing team boats allows for this higher frequency stroke to be practiced without the need for such strength. Eventually, increased stength + improved technique at high frequencies allows for higher boat speed.

Alright, now for some review of today's afternoon cycle. I've come to realise a decent competitive pedaling frequency should not dip below 80 rpm. Anything below that seems to fatigue my leg muscles. A good working heartrate I can maintain is at 79%, around 160 bpm. Accombination of the above 2 gives a good pace. This is achieved through the changing of gears according to conditions (slopes, wind). The only times a variation is required is for gathering speed and sprinting up a short but sharp incline, or when resting during a descent.

Speed is often not a very good indicator (although high speeds do boost morale, hur hur). For example, the same stretch of Lim Chu Kang I passed on Wednesday morning 6:20am at 40kmh at 80%, this afternoon 11:30am, I passed it at 30kmh at 83%. This is when drafting would really, really help, but that's not allowed at ironman 70.3. (It's only allowed for elite athletes racing the olympic triathlon and shorter distances)

And I shall mention some cycling technique here. Yes, surprise, cycling has technique. The cycling stroke is essentially a circle, and turning the crank uses different sets of muscles at different times, which is a good thing if not your muscles would not get any rest at all.

Although the crank is moving in a circle at constant speed, we can break down the stroke into 4 parts: down stroke, back stroke, up stroke and forward stroke.

1. The down stroke is essentially what everyone is familiar with, and where the bulk of the power is applied. A pushing motion using the quadriceps.
2. The back stroke is when your foot is at the close to 6 o clock, and is essentially a potential dead spot in the stroke. A pulling motion using the hamstrings
3. The up stroke is like the reverse of the down stroke, another potential dead spot. A pulling motion using the hamstrings.
4. The forward stroke occurs when the foot is near the 12 0 clock position. A pushing motion using the quadriceps is required.

Contrary to what I may have believed last time, the forces going through the cranks, ideally are NOT constant. The down stroke is where most of the power is applied. Followed next by the forward stroke. These 2 strokes make use of the possibly largest group of muscles in the body: the quadriceps. The back stroke and up stroke use the hamstrings, and as I have read and concluded only serve to reduce the IMPEDIMENT to the downstroke and forward stroke of the other foot. Yup, you pull back and up with enough force only so that you don't get in the way of your other leg applying power! The only time this is not the case is during sprinting, where you have to recruit even the strength of your hamstrings but only for a short time. This is so because the hamstrings are essentially quite a weak muscle group, and even with training will never be able to sustain you over prolonged periods. In triathlon, this is even more important as you really want to save some hamstrings for the run... Crampy hamstrings are no good.

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