• Thin or not thin – what is best for performance?


    Hi Gale! I have a question and haven't been able to find a satisfactory answer. It seems there's a trend towards not being overly lean for long distance athletes. The latest article coming from Sutton. In it he says, "...too much weight loss will negatively affect performance on the swim and bike..." I get the swim but if this is the case for the bike why is there such a focus in the cycling community to be lean?

    There's a ton of articles like this one on TrainingPeaks about why it is important for cyclists to be thin. So it seems like a conflict. If being to lean negatively affects the bike why are cyclists seeking to be lean and seem to perform better as such? Any help or insight would really be appreciated.



    Hi Anna,

    The debates about body weight for endurance athletes can certainly be confusing. If you want the short answer skip right to the end. For more explanation, read on.

    When looking at body weight and performance, I think there are several things to consider. The first thing is your specific sport.

    Sport demands in cycling

    In cycling road racing there are several specialties within the peloton. Sprinters need enough endurance to be in the finishing pack at the end of a race, but they need to generate enormous power to get primes and overall race wins. These riders generally carry more muscle mass and weigh more than the climbers.

    Road racing climbers tend to be the leanest of the cycling community. They are very light and can power their way up climbs while sprinters and time trial specialists suffer terribly.

    Time trial specialists likely carry more mass than climbers, but less than sprinters – though I don't have data to support this concept. They don't need high-end power production, but they specialize at redlining lactate threshold power for extended periods.

    General contenders, or GCs, for stage race races need some of each specialty in order to be ranked highest overall.

    Using the advantage of the peloton for road racers is critical. Deciding how to reserve enough power in order to unleash your specialty at the right time is part of racing strategy. The 2014 World Champion road racer crossed the finish line in 6:29:07

    Mountain biking

    Notice in the TrainingPeaks link that the mountain biking world champions tend to be slightly heavier than road racing champions. These riders need upper body strength in order to be skilled technical riders. They do not have a peloton to pull them for some portion of the race and their race is shorter. World Champion in 2014 crossed the finish line with a time of 1:27:06. This is essentially a solo effort.

    World Cup Triathlon

    Changing sports, International Triathlon Union (ITU) triathletes are swimmers, peloton pack riders and runners. When Craig Walton was racing (referenced in the Sutton column), he would absolutely crush other men on the bike. He could typically put enough time between him and the others on the bike that he could often hold them off, even in drafting races, on the run.

    Around this same time Barb Lindquist and Sheila Taromina, to name a couple of the top swimmers, would work together on the swim to gap the field and then work together on the bike to put in an enormous lead before the run began. Few racers could run fast enough to close the big gaps.

    The goal for many triathletes at that time was to work on swimming in order to be fast enough to stay with Craig, Barb, Sheila and Loretta Harrop coming out of the water so they could ride together and put time on the rest of the field.

    The sport has changed since that time and we seldom see solo efforts off the front of the field on the bike. Many triathletes now possess a high level of swimming and cycling power. The 10K run paces have gotten faster as well. Of course there is course consideration (hills or flat) and heat as well, but here is a glimpse:

    World Champion or Grand Final Champion







    Alistair Brownlee







    Ivan Rana







    Olivier Marceau








    These athletes need the power and speed to swim, bike and run around the two-hour mark.

    I traveled to many World Cup races between 2000 and 2011. The athletes that appeared to be trending toward very thin did not do well across the season. They might have had one great race or two, but they were often sidelined with illness or injury in subsequent races. If not sidelined, they seemed to lose power and speed as the season progressed. It was not the skinniest athletes that had strong, consistent race seasons.


    The 2014 Ironman World Champions were Mirinda Carfrae (9:00:55) and Sebastian Kienle (8:14:18). Obviously this race is over four times the time duration to completion as ITU racing. There is no (or not supposed to be) any drafting on the bike. It is a solo, time trial effort. Recall in professional cycling that the time trial specialists are not the "skinniest" riders.

    Mirinda's ride time (5:08) was 56 percent of her total race time, Sebastion's was 53 percent (4:21). Because the bike alone takes over half of the race time, a strong bike ride is critical to Ironman success.

    Of course, strong ride alone won't win Ironman. We saw Mirinda pull off a come-from-behind win off of the bike by running down the other women. If you look at her finish-line photos, she has quite beautifully defined muscles. She is a powerhouse.

    Thin to win?

    Athletes need to be lean, yet powerful. This does not mean skinny.

    Athletes must train their bodies for the unique demands of their sport. For some, this means carrying more body mass than others. More mass is more power and it is an advantage for particular sports.

    Optimizing weight must never come at the expense of health. Sickly or injured athletes can never complete the training volume and intensity necessary to optimize personal performance potential.

    What does this mean for you?

    Track your health markers to be sure you stay in the optimum ranges suggested by your doctor. Complete blood panels once per year are great because you can watch for trends. Additionally, you can do a mid-season check if you don't feel good.

    Body weight is but one measure. If you are aiming for podium performances, it is safe to say you cannot be overweight. However, if the number on the scale is your only goal, I suspect you will never be able to find your potential.

    Monitor sport performance and how your clothes fit, along with body weight. With these measures and your health markers, you can optimize your performance.

    Hope that helps,

    Coach Gale

  • ← Next Post Previous Post →
  • Leave a comment