05 May 2011

Hill Sprints

So today was the day to get out on the road and do some hill sprints - up hill and down dale! First task was to try to find the best spot to do these. I eventually settled on Diamond Creek Road, between St. Helena Road and the big roundabout, as it's long, wide, and has a fairly constant rate of gradient change, except for one rapid change from 4-5% to 8-9% which, though it must be climbed/descended, doesn't form part of the actual sprints.

After a bit of a warmup/orientation where I chose the markers for my sprints, I headed back uphill to the starting point of my first attempt. I shifted in to 53x17, came as close to a stop as I could, and started off, trying to concentrate on my form. Upon reaching my finishing marker, I looked down to discover I'd only travelled approximately 60 of the required 80 metres! So I tried to dig in for the remaining 20 and looked for another tree to mark the new finishing point. Fortunately there was a handy one at close enough to the right spot, so I filed that one away and continued on up the hill to my turnaround point - which is not ideal, as it's an extra 200m or so of 8-9% climbing which makes it impossible to get back for a 4-minute cycle.

My stats for the uphill sprints were (approx) 73/25.2km/hr, 70/27.6, 66/24.6 and 74/29.3, starting (I think!) R,L,L,L, all in 53x17, all seated, not out of the saddle.

Downhill sprints were a little smoother, though I changed gearing for the last two - from 53x13 to 53x14 because the cadence was a little low. In theory each should start at a cadence of 120, but that's a bit tricky! Sprinting from 120RPM for 8 seconds should presumably see some sort of an increase, but my 4 results were:

i) Entry 114/59.7, Max 121/64.6
ii) Entry 113/59.4, Max 121/61.9
iii) Entry 117/56.5, Max 124/59.2
iv) Entry 115/59.4, Max 124/63.3

The slope is still approximately -1% at the start of the sprint, so I wonder at the extent of the influence of the slope. Clearly the entry speed makes a big difference to the final speed, even though my cadence on entry was lower in the final attempt. Interestingly, though max cadence was slightly higher once I dropped down a gear, entry cadence wasn't significantly greater, suggesting that the limiter of spin speed was me, not the gear. Which is odd, considering that in the 'spin' on Tuesday I was maintaining 130+ for 10 seconds or so - though that was absolutely head down smashing myself, which I wouldn't do on the road since I like to see where I'm going then! I didn't notice any rocking of the hips though. At any rate, much work still to do.

Brief stats here.

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