Why Chasing PB’s can be harmful

Fitness Trainer

Personal best times and distances are a very important part of the sport of triathlon. PB’s are often the reason some athletes seek out a triathlon coach Melbourne or Ireland based, or for online triathlon coaching.

In disciplines like swimming, cycling and running, personal best records are subject to all sorts of external conditions. These uncontrollable environmental factors, in most cases, make it difficult to compare races, even if we are talking about the same course. In this blog, we will discuss why being fixated on only personal bests can become a debilitating problem for your physical and mental health.

It must be noted that by nature, both running, and triathlon are sports that are mainly completed outdoors. This means that every participant is subject to all sorts of conditions such as, weather, course route, elevation, etc. These elements affect some disciplines more than others, so let’s have a look at how each leg of a triathlon can be affected.


The swim leg has some of the most unpredictable conditions. Air temperature, water temperature, the depth and floor profile of the ocean, wind, waves, sunlight, natural flora and fauna, sand type and depth just to name a few.

Swimming distances for a Sprint Distance event can range from 500m to 750m. Comparing each swim to the last swim time requires using your overall pace instead of overall time.

Another element that comes to mind when considering the times of a triathlon swim is whether you are swimming in a lake or in the ocean. A freshwater lake is far less buoyant that the salty ocean. This added buoyancy will help improve your body position and increase your swimming speed. This can make a big difference between triathlon courses even of the same distance.

The last element to look at in the swim is the human factor. In some races, organisers might decide to create a course in a way that you get a better result or a more comfortable course. For example, in some races, the course is a triangle, some it’s a square, some it’s an ‘M’ shape and sometimes it may consist of 2 laps with a small portion of running in the sand in the middle.


When thinking about the cycling leg, most athletes will instantly think about wind and drafting as fundamental factors of overall speed on the bike. They would be right, but there is much more to it than what meets the eye. Not everything is watts.

Firstly, we need to consider the drafting rules. Some races are draft legal, others are not. Some races have a huge number of athletes out on course at the one time. This means that if you are actively moving up though the field, you get the drafting affect coming into play as you approach and pass each slower rider.

Another element that is rarely considered in Australia but is prevalent in our Irish races is traffic. If there is traffic on a side road moving in the same direction, a drafting tunnel will be created helping athletes get that extra bit of speed. At the same time, there are also the chances of a tractor popping out of the local farm that will cause you to slow down!

Other elements that influence the athlete’s performance on a bike leg are course elevation, the number and steepness of any hills, U-turns, corners, road surface, tyre pressure, clothing choice and the amount of fluids and nutrition you are carrying on the bike with you.


Temperature and humidity are two of the biggest elements to consider when facing the run leg. And of course, a run leg with more climbs will be harder to tackle than a flat one.

A good rule of thumb is that for every degree above 15ºC, our expected pace should be increased by around 1 sec/km. For example, if you are running in 33ºC heat, you are running 12 secs/km slower, equating to approx. 4 mins on a half ironman 21.1 km run course. All of these calculations are assuming that you have met your required hydration and nutrition needs.


All transitions are different. There is no rule about how long a transition must be. Most athletes who have done the triathlon series in Melbourne will remember the short flat 100m jog in St Kilda as opposed to the 400m uphill climb in Sandringham. Things like this will add huge chunks of time to your transition splits.

*Fun Fact: Athletes who run the Sandringham Enticer triathlon run more from the swim to the bike transition than what they run on the actual run leg.

For all of these reasons, it ends up being almost impossible to compare one race with another. As athletes, we are able to control a certain number of variables, but it is impossible to have complete control over everything that happens around us. There comes a point, in both a coach and athlete’s eyes, where a 4:30:00hr half ironman on a flat day in good conditions becomes less valuable than that same distance in 5:20:00hrs under tougher conditions.

The moral of this blog is to stop stressing by thinking solely about a personal best. Letting that define your success not only becomes tortuous, but also useless when comparing it to the big picture of a sports program. Getting a PB is one of the goals, but a good program aims to develop consistency in your health and fitness. It is meant to allow you to practice the sport you love for years. Most important, a good sports program should work towards giving you years of happiness, health and open the door to a dignified old age in years to come.

Leave a Reply

Your email address will not be published.