This post highlights a way I approach coaching busy triathletes, including Ironman racers.  This “minimum effective dose” approach was the foundation of my 10 hours per week Ironman training experiment.   However, it’s a good way for ANY triathlete to think about their training.

Most triathletes, especially Ironman racers, (as well as some coaches) think of training primarily in terms of overload and adaptation.  In other words, they pile on as much training as they think they can handle or whatever they think it takes to achieve their goals.  They feel the more they can pile on without injury, the more their body will adapt and get stronger.

This is the classic “more is better” idea that is so prevalent among triathletes.  The problem with this idea is that it doesn’t work for many people, especially if they are busy and stressed out to begin with.   Even if we have a strong foundation for adaptation, if we train too much we exceed our body’s capacity to absorb the training and get faster.   Our bodies are so tired that they can’t muster the energy to heal and make the changes necessary to get faster.  We end up tired, grumpy and frustrated at the limited results we are getting for our hard work.

Instead of “Overload and Adaptation” think of our training in  terms of “Dose and Response”. 

Our training needs to be at a “dose” below the maximum we can absorb and above the minimum it takes to keep us improving.   That’s the sweet spot.   Go above what you can absorb and the dose is too much.  If the dose is too small,  you will stagnate   If you are like most triathletes, right now you are thinking, “OK, I’ll target the maximum training I can absorb.”   But, especially if you are busy, go the other way and ask yourself  “what’s the MINIMUM training I can do and keep improving?”   That level is your “minimum effective dose of training.”

A friend of mine once told me that he wanted to improve his swimming so he started swimming close to 20,000 yards per week.  I asked him if he was getting any faster and he admitted that he wasn’t.   The same might happen to someone who starts biking 300 miles per week.  Even for “low impact” sports like cycling and swimming, if you do too much your body might be too darn tired to respond and get faster.   Of course there are stories where an “overload” approach works for some people.  Those people have great recovery ability and a big natural capacity to train (and plenty of free time).  If that’s you, a “minimum effective dose’ approach might not yield the best results, but the rest of us should consider it.

At least for the first part of your race builds, target that Minimum Effective Dose.

Start relatively small and make your training a just a little bit harder as you go along.  If you find you are getting stronger week by week without excessive fatigue, you know you are doing “enough,” even if you feel like you could do more.   Eventually your training will be quite “real” and challenging but always remember that we want the minimum you need, not the maximum you can do!

Example 1:  Let’s say you are returning to run training after a break.   You start off with 25 minutes nice and relaxed at under 140 bpm for your first “long run.”   Let’s say you felt a little tired at the end of 25 minutes.    The next week you do 30 minutes are you are slightly faster and you don’t feel tired at the end.   The next week you do 35 and are still improving.   Then all of a sudden you feel you are back in shape and want to run an hour the next week.  DON’T DO IT!!!   As long as you are seeing improvements, stick to small increases, even if you can “handle’ much more.

Example 2: you are on a 10 hours per week training plan  in the first half of your build.   As long as you are improving, you don’t need to add more and more volume.   If your speeds are going up and you are feeling stronger at the end of our workouts, we know the “dose” of training is effective.

More notes:

  • Give yourself time to build more slowly.  Start your build (especially the first build of the year) with enough time so you don’t have to rush things.


  • At some point, you will have to transition from “minimum effective dose” mode to “be ready for the race” mode.   You’ll need to start making sure that you are ready to “go the distance” for your A race.   If you build correctly, you’ll have have come close to maxing out what you can do on a relatively minimal plan and can get a final bump from the bigger training.


  • Remember it’s a build.  As you get fitter, your body will need a bigger “dose” of training to keep improving.   The perfect dose at week 4 of your build will be too easy at week 10.   And, of course, hard 4 hour rides might the perfect dose for 6 weeks out from race day, but it would be too much on week 3.   That’s one of the biggest mistakes I see self coached athletes make– not building methodically.


  • The 6 week rule: as a general rule, you’ll start hitting diminishing returns after 6 weeks of a certain type of training.  That’s why we target a good 6 weeks of bigger training before an Ironman to get fit.   After a good 6 weeks of long rides, e.g., you might get  over 80% of fitness you’d get from 12 weeks of long rides.     A basic build might be structured as: (a) 6 weeks “get back in shape training; (b) 6 weeks solid 10 hours per week training; (c) 6 weeks bigger “be ready to race” training, followed by (d) 2 week taper.

If you are a busy athlete, take a minimum effective dose approach in the first half of your next build.  You’ll feel better, improve steadily, and probably have more time and energy for recovery and life!

Here at TriForce our mission is to support you in being a lifelong athlete.   If you have any questions or ideas for blog posts please let us know in the comments.

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