People ask what’s the one thing I can do to improve my times and I tell them that the number one mistake that most triathletes make is training too hard on easy days and too easy on hard days. Simply put, each workout is designed to train either your aerobic or anaerobic system, so you train within a specified heart rate training zone. The mistake is that people tend to train down a zone on their really hard days and up a zone on their easy days, which changes the focus of the workout. Let me profile a set of athletes to help explain.

Each athlete is training for an Olympic distance triathlon and runs about an 8:00/mile pace in a triathlon. They did two run workouts one week; one was a threshold workout and the other was an LSD (Long Slow Distance), over-distance run. The results of their threshold workout were as follows:

At first pass, nothing seems wrong with these results, until you see that they didn’t push either their PE into the very hard effort level or their HR into Zone 5, the focus of the workout, to train their anaerobic threshold, AT; they were running using primarily their aerobic system, not their anaerobic system. Because of this their AT will either not increase or only increase slightly because of this workout. To be able to swim, bike, and run faster, you need to raise your AT so you can go faster longer. The workout these three athletes did leads to plateaus in an athlete’s training, even though they think they’re training hard enough.

Note, if you’re not all that familiar with using a HRM and heart rate training zones, I refer you to Joe Friel, the author of the Triathlete’s Training Bible and many other sports related books, as one of the best references. Google “Joe Friel, heart rate zones” for more information, or better yet, read his books! I added a Run HR zone chart at the end as an example.

If the athletes looked at their average HR for the workout, they probably thought they got in a good workout, with a high average. For this kind of workout, your average HR isn’t that important. What is important is their average and/or maximum HR was for each of the 8OOm laps they performed, going high enough into zone 5 to be beneficial.

Ultimately they fell into the trap we all fall into, settling into a pace that is in our “comfort” zone, and not the one we were supposed to be running in. The bottom line is that they ran too easy on their hard day.

The results of their LSD workout were as follows:

Again, nothing seems wrong with this workout, until you see that none of the athletes ran easy enough or long enough in what is basically a long recovery run. Their legs were not that tired from their threshold workout as it wasn’t run hard enough. As such they felt good and proceeded to run too fast on an easy, if not, long run. This type of run should be run at “conversation pace”, so that you and your training partners can hold a somewhat clipped but complete sentence conversation. If you can’t do that, then you’re running too fast.

The other issue is classic of athletes that run based on distance alone, and not on time, they didn’t run far enough. They only covered about seven miles, not really the definition of an over-distance run when you’re training for an Olympic distance tri. The idea behind LSD and over-distance runs is to work on muscular endurance, the ability for your body to continue moving, regardless of pace. This seems counterintuitive to many athletes, that running slower and longer is more beneficial than running shorter and faster. To define how long these runs should be, use your expected 10k race time and add 25%. For an 8:00/mile runner, that’s about an hour, while they focused more on distance and came up a little short. This is why they made the second mistake and ran too hard on their easy day.

If you look at these results and understand the subtle difference in what they were trying to do and what they actually did, then you realize that it only takes a bit more focus during your workouts to make an okay training day into a good training day. By paying attention to the purpose or focus of the workout, be it a threshold run or a LSD run, in the end your body will gain the benefits of going hard on the hard days and easy on the easy days. Do that and you can start working on the #2 mistake that triathletes make!

HR Training Zone Chart

Below is an example of a HR training zone chart taken right out of Joe Friel’s book, for an athlete that has done an AT test to determine their anaerobic threshold HR. Based on this number, 162 in this example, the associated HR zones are calculated, as well as their HR range for each zone.  These zones are specified in the athlete’s training plan to define their effort level for each workout. For the examples above where the athletes didn’t train hard enough during the threshold workout, it is that last 5-10% of effort that helps our bodies develop and potentially raise our AT. The same for their LSD run, where they were working out in the intensive endurance zone versus the extensive endurance zone, and didn’t run long and easy enough to develop their aerobic base further.