Your training is working if you are improving from one training block to the next. However, measuring improvement can be a little more tricky for an age group Ironman athlete than for an olympic distance athlete. A strong olympic distance triathlete can measure improvement in simple intervals workouts. For example, if they can hold a higher wattage for 2*20 minutes with 5 minutes rest, or if their 5k race time improves, they know that they have made improvements that are likely to have a strong impact on their race day performance.
However, the key improvements that most age group IM athletes need to make are a bit more slippery and difficult to measure. While some believe that improving your threshold is the sine qua non of improving your IM performance (it’s not), I’m looking to see an improvement in at least one of the following from one training block to the next:
1. Steady Endurance. I consider my endurance to be improved when I can maintain IM power or pace for a longer time without a major uptick in HR (heart rate) or PE (perceived exertion). I can measure this easily because I do lots of steady indoor sets with power. If during the last training block I could do four 30 minute steady sets before my PE & HR jumped up, and this training block I can now do 5, then I know my endurance has improved. The same thing applies to longer runs. This is the MOST important improvement I’m looking for. In fact, if you are worried about your ability to complete the distance without hitting the wall, this is pretty much the only variable that matters.
2. Improved Pace or Power @ IM Heart Rate (or keep the same speed or power with lower heart rate). Using heart rate as a measure of intensity is out of style right now, but heart rate is an essential thing to keep an eye on. While it can vary on some days (e.g. when it is hot or the day after heavy drinking), I have found HR to be quite reliable over time. If you don’t know your IM heart rate, then use the bottom of your Friel HR zone 2 as your benchmark HR (although any very comfortable aerobic HR will do) . You want to see your run pace and bike watts increase at that heart rate over the course of the season. Again, this is where indoor bike workouts are an essential tool to measure improvements. It is also useful to have a relatively flat run course that you can repeatedly run through the season with the same heart rate ceiling. This is the second most important improvement I’m looking for.
3. Ability to Recover After High Intensity Efforts Within A Workout. After I ride hills or do higher intensity reps within a workout I’ll return to my steady pace or power. I know I’m fit (and able to handle a “spiky” race) if my heart rate and perceived exertion quickly return to normal levels, even at the end of long, tough rides. If this isn’t the case for you by race day, then you’ll likely do better by being quite conservative on the hills during your race.
4. OK, An Increase in FTP Would Be Nice. Functional threshold power (FTP, or the max power you can hold for an hour) is measured by a variety of tests (some more accurate than others). Coaches and athletes love these tests because they create very concrete results that can be measured. There is also the misunderstood piece of wisdom that your FTP is the best predictor of your IM bike performance. An increased FTP is obviously a good thing, but be sure that you don’t fry yourself so much in the pursuit of a higher FTP that you don’t have the energy to do sessions that address #s 1-3. Most AG athletes have their hands full pursuing improvements #1s-3, but only top athletes who have no doubt that those elements will be strong on race day can afford to let those improvements take a back seat to pursuing threshold specific training for part of the year.
5. Ability to Handle More Training Load. If I can train more in the next training block without more signs of fatigue and with continued increases in performance, then it is a good sign that I’m developing the overall strength and capacity that is helpful for IM. This can be measured using the performance manager in Training Peaks (with very cool charts). Just remember that increased training load is a means to produce the results listed above, not necessarily an end in itself.