One week in numbers:
Bike – 380km
Run – 66km
Swim – 2 hours
This coming week will have similar totals with a nice upbeat tempo and small intervals of race pace during my training sessions. I am really pleased with my flat running speed average during training sessions as I am cruising at 4 minute 21 second kilometers. If I can average this pace in the Ironman I would be very pleased and it would mean running a low 3 hour time over the Marathon distance. I only hope my legs know how to run like that after I get off the bike after the 180km cycle!
Cycling is on track with 33-34km/ph averages on rides around the 100km mark which have tended to be anything but flat rides so the goal will be to see if I can average between 34-35kmph average during Cairns. I think if I maintain this speed it will allow me to rest my legs sufficiently for the run. Swimming, well I’m sick of the black line on the bottom of the pool enough that I can admit now that I have not been swimming as much as I would have liked to, but as a fellow competitor once said to me, it’s only 10% of the race. I am still confident I am capable of that low 1 hour time but more realistically I think it’ll be around the 1 hour 8-10mins as the course is a two lap, which means more swimming around congested buoys which is so nerve-racking with the numbers in the water (something that I could do without at the start of the longest race of my life).
Something I found out just before mothers day was that my mother is also in the 5km Run/WALK in Cairns. So excited to see her out there enjoying the atmosphere as well. Happy mothers day mum, I didn’t realise you were also getting this blog until you told me about the 5k!
Dinos Cycling tip – Ways to reduce cycling energy requirements
At speeds over 16km/h on level roads most of the energy cost of cycling comes from overcoming wind drag. Riding immediately behind another rider can reduce the energy cost of cycling on a flat road at 40km/h by over 25%; riding in the middle of a tightly packed bunch can produce energy savings of up to 40%.
Drafting has been described as a very important skill for a competitive cyclist since it can have a huge impact on energy requirements. Scientists analysing data from Tour de France competitors have remarked not only on the exceptionally high power
outputs, but also on how riders are able to use drafting skills to complete stages with surprisingly low average powers. One rider was able to complete a six-hour stage of the Tour with an average power of 98W despite a 40km/h average speed.
In our case, the data was from one rider in a group of just three, so there was limited potential for drafting. However, since many thousands of riders take part in the Etape, drafting is one of the most effective ways of reducing the energy cost.
The downside for riders using these skills in the Etape is that fast moving bunches tend to keep moving quickly on the climbs. One of the first things people notice when riding a cycle equipped with a power meter is how even small gradients have a huge impact on power requirements.
Recently, scientists modelling cycling time trial performance have debated the merits of using more power on climbs than on flat and downhill sections. The reasoning is that wind drag increases as a cube of the speed, so, for example, much less effort is needed to go from 16 to 17km/h than from 30 to 31km/h. This means that going harder on climbs will theoretically result in faster times than an ‘even power’ strategy because the energy losses through wind drag would be lower.
Pedalling cadence and energy
Failing to change down gears when pedalling cadence falls can also increase the rate of carbohydrate usage. Low pedalling frequencies increase the torque on the muscle and so increase the recruitment of fast-twitch muscle fibres.
These fibres prefer to use carbohydrate as a fuel since they lack the enzymes necessary to process high quantities of fat. The SRM trace shows that in our example cadence dropped to less than 50rpm for significant time periods (especially towards the top of the first climb) with a gear of 39×27. Most competitors in the real Etape would do well to have gears at least this low.
Although gradients may not look so great on course profiles, competitors need to take account of the length of the climbs and also the effect of altitude. Aerobic power declines by about 5% when compared to sea level at elevations of as little as 500m.
Cheers all, happy training to those who are out there training for their own events. My brother Peter’s marathon running training programme has started and sounds like it is going well. Keep it up Pete!!
