Fatigue Early In Bike Leg During Triathlon

by JR
( Wokingham)

I have competed in 11 triathlons - mostly sprint - over the past 3 years and I suffer from fatigue early in the bike leg in race conditions. I start OK but then find that after 2-5km my heart rate and blood pressure rise and my legs lose all power.

I have spent the winter doing endurance training to increase my lactate threshold. Have you any advice that will help me?

Mark replies:

This is a fairly common problem, particularly early in the season. People come out of winter training and struggle to put the 3 disciplines together.

There can be a variety of different issues that lead to this problem and one, some or all of them may be relevant to any individual. The trick is to find the most significant and address this.

The first reason could be that you don't train as a triathlete. Remember that the sport is one event, made up of three disciplines, not three sports bolted together. The issue you describe is very common with single discipline athletes transitioning to triathlon, especially runners and cyclists. They find that they cannot access all of their potential in their specialist discipline.

Do you do any 'brick' (swim to bike or bike to run) sessions in your training? If not then I would begin to include these in your programme.

As it is the bike you appear to struggle with this would seem the obvious place to start. If possible, do a normal swim session, but have your bike available. Finish the swim on a hard section, get out, change into race suit quickly (not necessarily race speed) and head off on the bike. Initially it does not need to be too long a ride, maybe 15 - 20 minutes and only moderately hard (below threshold). After a couple of weeks begin to make the ride harder. Set out just below what you would expect to be race speed, and build through the 15 - 20 minutes to above race pace. You should begin to find that it is easier to build the pace and then maintain it.

If it is not practical to get out on the road, see if you can set a turbo up in the gym or somewhere convenient. Poolside is usually not a good option as they are often really hot and humid and you will feel awful!

Have you assessed how much you have improved your lactate threshold and do you have a good idea for what your LT2 Heart Rate is?

It is possible that you are trying to get up to race speed too quickly, and pushing yourself over the 'red threshold line' and this weak feeling is your body making you calm down before allowing you to build up again.

Another reason for struggling early in the bike that I have encountered occasionally is the change in orthostatic blood pressure. Swimming is obviously performed with you in a horizontal position - lying flat. As you stand up and run to T1 all the blood that has been spread out through your body is suddenly pushed to your lower extremities. This can cause dizziness and loss of power. This usually occurs in people who have a low resting blood pressure, as this means the blood can be re-distributed very quickly around the body.

You say you have been trying to increase lactate threshold. Does this also include swimming? Is it possible that in your Sprint races you are swimming at a higher pace for a longer period than you are used to in training? If so then it could be that you are putting yourself in to the red before you get onto the bike and therefore you have to recover before you can begin to push properly.

Another related issue could be that you use your kick excessively. This will lead to local muscular fatigue in your legs and make it difficult to ride powerfully. There are lots of thoughts on the ideal leg kick in triathlon (2, 4 or 6 beat). What doesn't change though, is that the kick needs to be primarily for balance in your stroke and not as the dominant means of propulsion.

Hope this helps!

Click here to post comments

Join in and write your own page! It's easy to do. How? Simply click here to return to Ask The Triathlon Coach.

 Be Coached By Intelligent Triathlon Training!

 Achilles injury? Our e-book will get you back running pain-free

Sign Up Below
To get free triathlon training tips,
news and ITT site updates, and a
FREE Training Planner!
Find out more

Enter Your E-mail Address
Enter Your First Name (optional)

Don't worry — your e-mail address is totally secure.
I promise to use it only to send you Intelligent Triathlon Talk.

Bikes & Reviews

Wetsuits & Reviews

Beginner Triathlete