I explained in my previous post on “Monitoring My Triathlon Training” about the concepts of:
- Functional Threshold Power (FTP): The power one can race at for one hour;
- Intensity Factor (IF): The ratio of the power on a ride (NP) to the FTP (IF = NP/FTP); and,
- Training Stress Score (TSS): Which is the demands of a ride (TSS = IF^2 x Duration in hours x 100)
In this post, I will bring the concepts together to explain my training approach and how I hope to use it in racing during 2009.
Training with Power
Triathletes are very familiar with the concepts of training cycles. We have a base period and then build to the race fitness. For 2009 I have adopted a different approach to training, as put forward by ‘Endurance Nation‘. It can be summarized as ‘Fast then Far’. Essentially, the off season is used to train to build power and speed, with the volume coming later.
So my training weeks are consisting of a lot of interval sessions. These see my riding up towards my FTP with the goal of increasing the FTP. So why not go past the FTP in training since that could conceivably make me faster? Because the cost of doing so is too great in terms of the recovery time needed.
The graph below from Hunter Allen and Andy Coggan’s book shows this. The red line is the physiological strain of arising from different intensities. Above 100% it increases rapidly, especially above 120%. The blue line is the duration at which one can maintain that intensity. The black line which is the training effect. This shows that once you get above 95% of your threshold power, there is a negative impact on your overall training.
In training one tries to stay in the ‘sweet spot’ of about 83-97% of FTP. The calculator below from FastCat Training shows what the range is for me with my current FTP of 230 watts. I do most of my training in the zone 191-223 watts, generally at the higher end of around 220 watts.
In case you are wondering, RPE is the ‘Rate of Perceived Exertion’. It is a scale of how hard you feel you are working. I am still trying to master that one.
Racing With Power – The Theory
On the basis of my training, I will know my FTP before the race. The key question is ‘so what’. How will this help my racing? Endurance Nation argues that if you use up more than 270-290 TSS on the 180 km bike ride in an Ironman distance race, you will blow up on the run. They have a chart which shows the intensity factor vs the proposed bike split to be within that TSS range. For me, with a hopeful 5:30-5:40 bike split that works out as an IF of about 71%. An excerpt from their chart is below (you’ll need to buy the full chart as part of their training program).
From this IF there are four recommended power ranges that I should use in the race, as shown below. I’ve taken the liberty of assuming my FTP will be at 250 watts by the time of the race.
Most of the race should be spent at 178 watts, after a 30 minute ‘warm-up’ at 169 watts. Their argument is that by staying at this power, and keeping the power variability to a minimum, you will have done the bike ride in the most efficient manner possible and saved your legs for the run. What I have not worked out is whether cycling at that goal power will give me the desired bike time–that will come during my build season.
So that’s my approach for the 2009 season. Looking forward to seeing how it works!