Recently, the IRONMAN calendar for North America has shifted to late summer and fall dates. This means that if you are signed up for an IRONMAN race this season, you have at least seven months of training before race day. With plenty of time to prepare, long indoor sessions over the winter are unnecessary.
Common Training Cycle
Most triathletes view the winter as a time to build their base fitness. Then, in the spring and summer they spend their time in various phases like the Build or Base 2 phase. If you start building your base fitness now it means long sessions indoors or fighting less than ideal conditions.
In my view, this is a bit of a backwards approach. Your training should move from more general to more specific as you move towards race day. Why do all the specific training early, then move to the intense work as way to “sharpen up”? Rather, it would be best to set up your training so you are performing your most specific training close to the event.
Using Reverse Periodization
I believe that you are more likely to have success by building power and strength first, then moving to the long distance training necessary for IRONMAN. This approach is often called Reverse Periodization.
This approach to IRONMAN training makes more sense when you consider the time of year and weather conditions. Trying to build base while on the trainer or treadmill is demanding both physically and mentally. Plus, even if you do get to a point where you can ride for five hours on the trainer, you still will have four to six months before race day. There is no need to build your endurance up so far away from race day. Instead, you should spend the winter doing shorter sessions that focus on intensity to become a faster and stronger athlete.
During the General Phase of 12 to 16 weeks, your goal should be to raise your Functional Threshold Power (FTP) and/or Lactate Threshold Heart Rate (LTHR) for the bike and your Lactate Threshold Pace (LTP) and/or LTHR on the run.
For age group athletes, IRONMAN is raced at 60 to 75 percent of your FTP and/or LTHR. So, if your FTP is 250 watts, you would be racing the bike around 175 watts. If your FTP is 280 watts, you can race at 195 watts. This means more speed at the same physiological cost.
There are many ways to increase your FTP on the bike and LTHR/LTP on the run. A typical session focuses on intervals at around 90 percent effort. Do not be too concerned about your power or pace when you start. You won’t have your goal race pace fitness yet, but as you stick with it, your power and efficiency will increase.
After building up your power and speed during winter, you can take your new power levels and start working on your endurance in the spring when you have more daylight and warmer temperatures. The Specific Phase lasts from 12 to 16 weeks depending on your goals and how long you have been in the sport.
During this phase is when you start to include the longer rides and runs on the weekends with the focus of building your aerobic capacity. With a higher FTP gained over the winter, your power will also be greater at lower intensities. If you start this phase in March, you can easily be ready for an IRONMAN in August or later without pressing your build up. If your longest indoor ride was three hours, building up to a six hour ride can easily be done over 12 weeks.
Added Benefits for Early Season Races
A proper Annual Training Plan will have you racing one or more shorter, B priority events before your IRONMAN to test your fitness, try equipment, work on nutrition, etc. If you’ve spent your winter getting more powerful, you will be able to perform better at these events as well.
You may be doing an IRONMAN 70.3 race in June, and with months of power and speed work under your belt you will be primed and ready to have a great race. If you’ve spent months riding moderately for long periods, you will struggle to cope with the intensity of shorter racing.
With an IRONMAN calendar loaded with late season races, there is no reason to rush to build your fitness over the winter. Instead, use your training time wisely and effectively to reach your goals.