40th anniversary of BolderBOULDER – facts and stats


BolderBOULDER in Boulder (Colorado) belongs to the top 20 of the biggest road running races in the world. On Monday, 28 May, it celebrated its 40th anniversary. Let’s have a look at the statistics!

The event is not only known for its high number of participants, but also for its ceremonial aspects. The race takes place on memorial day, which a federal holiday in the USA to remember the people who died while serving the country’s armed forces. The event is very much associated with memorial day, as, for example, active military members are offered discounts on participation fees. Have a look at this video, in order to see how important the relationship between the race and memorial day is. A reason why this race is especially interesting for us is the fact that Frank Shorter, who is our ambassador, is co-founder and organiser of this 10km-long race. He is a long-time resident of Boulder and a life-size bronze statue of Shorter stands outside the stadium.

Now, let us turn to some facts about this years race. About 38’000 people finished the competition. While there is also a separate race for the elite runners, we would like to focus our analysis on the performances of the runners in the regular classes.

1) Nailing the 1 hour bench-mark

A first interesting point is the distribution of the 38’000 participants in terms of their running time. Graph 1 illustrates this:

Graph 1: Distribution of runners on running time

As you can see, the peak of the distribution is at 1:00:00. More than 700 runners completed the race in around one hour, while most runners had times above that. The number uf running times below one hour decrease strongly with decreasing time. Towards the other side of the spectrum, we see that the amount of occurrences per time drops rather fast at the beginning, while the distribution seems a little bit more even for the times between 1:30:00 and 2:00:00. A possible explanation for this pattern is the fact that the times of 60, 90 and 120 minutes all are some kind of bench-marks to which people try to orient and which they try aim for or to underbid.

2) 31-year old men and 36-year old women are the fastest!

Let us now look a bit more closely at the sociodemographic correlations with running times. First, we’ll look at the fastest time ran by members of each age class and gender. This is shown in graph 2.

Graph 2: Fastest time run by member of each age class and gender 2018

What we can see here is that, not unexpectedly, males generally had lower times than females. While the fastest 6-year-old girl was faster than the fastest 6-year-old boy, the fastest times for males were always faster than the fastest times for females. The smallest difference between the genders can be seen for the 36-year-olds, the 43-year-olds, the 54-55-year-olds, and the 70-year-olds. In general, performances improve rather fast in younger years, while they remain constant within a wide range of age groups, getting worse only after about 45 years of age. The best performances were delivered by 31-year olds for men and 36-year olds for females.

3) Slower as from the age of 45?

Also when looking at the average times of all members of each age group depending on gender, we see that the average performances of males are lower than the ones of females. Thee difference seems to be the smallest for the ages of 6 to 14 years, 26 to 28 and 76. Also this graph reflects the result above, that performances increase fast with increasing age at the beginning, while there are only small differences between the times of 20-year-olds and 45-year-olds. After that, times start to increase again. Also average times were the lowest for males around 30 and females around 35.

Graph 3: Average time per age group and gender 2018

4) Respect for the Alabama runners!

Another interesting fact to look at is the comparison of average times in this year’s race across the different states of the USA. The table below shows the average time for each state.

Table 1: Average time in 2018 for each state in the USA

The fastest average time was achieved by runners of Alabama with 1:13:16, followed by New Mexico and Maine. Somewhat surprisingly, the host state of the competition, Colorado, only scored the 36th best average time. However, the best time ever by a runner of a US American state was achieved by a Colorado runner (which we cannot see in this table, however).

5) Ladies chasing the men in the 70ties

Now, apart from the numbers of this years race, we are also interested in the comparison across genders and age groups over the years, as well as the development in performances.

Let us start with the best time ever run by members of each age and gender (since the first competition 40 years ago). This is shown in graph 4. We see a similar pattern as we did for the comparsison of times across age and gender for 2018, except from the fact that at some point in the history of the race, there were both a very fast 58-year-old and a very fast 68-year-old female. Also, the best times ever run by 73- and 75-year-olds were run by females, not men.

Graph 4: Best times ever run by members of each age group and gender

6) Numbers of records was increasing – is this about to change?

But what can we say about the level of performances across the years? Do people tend to run new records or are the numbers of new records stagnating? The following graph shows the amount of runners per year who ran a time among the best 20 times ever run by runners their age.

Graph 5: Amount of runners per year with a time among the all-time top 20 in their age group

The graph shows that a first peak with new records (over 100 cases) was reached in 1984, while it took 20 years until this number was reached again. After 2006, the numbers of new records for different age classes was always higher than 100, the highest ever number of new records being registered in 2015. The number of new records has thus been growing during the last 20 years overall. This year, however, during the last couple of days, we can observe a decrease. Of course, these results can be interpreted in different ways. The higher amounts of records might, for example, be explained by higher amounts of participants. However, in order to determine this, we would need to conduct a more in-depth data analysis.

7) People are faster than we thought…

Now, we also had a couple of running.COACH users running the competition! We are, of course, interested in the degree to which our prognoses for those users’ running times turned out to be accurate.

According to our calculations, our users were, in average, 0.6% faster than what we had said in our prognoses.


This blog entry was written by: Marion Aebi

How to reach your competition weight


Sports and nutrition scientist Dr. sc. nat. Joëlle Flück explains how you can achieve your competition weight and which individual factors play a role.

Our body weight fluctuates depending on the training period we are in. Especially when recovering from a long-lasting injury or a break from training we gain weight relatively easily. How can you get back to your competition weight? What do you need to consider?

Achieving a healthy body weight

Depending on the sport, the typical body weight is usually lower during competition season than during the rest of the year. The optimal competition weight is very hard to keep over a long period of time and during training season it brings with it the danger of injuries and illness. However, the difference between competition and off season weight should not be too big (< 3% of the body weight). This way, it can be avoided that the athlete has to lose a lot of weight within a short time frame. Before a big weight reduction you should always ask yourself whether this weight reduction brings with it a risk for your health, whether the goal is realistic (e.g genetic preconditions) and whether the goal is appropriate for your age and level of fitness. Further, you should be able to keep the weight without having to follow a strict diet all the time and without developing an eating disorder or a disturbed eating behaviour. Sports people who keep losing and gaining weight all the time probably have an unrealistic goal for their body weight.

Regulating factors for the energy balance

Different factors can considerably influence the balance between energy intake and energy usage. This can be, on the one hand, factors from the environment, and, on the other hand, individual factors such as stress, hormones or personal conditions. How much energy you use also depends on your individual restic metabolic rate (RMR). This is influenced by age, gender, but also muscle mass, stress or certain hormones. Depending on the athlete, this energy varies between 1300 and 2500 kcal per day. For a more accurate determination of your individual restic metabolic rate, it is recommendable to conduct a measurement in sober conditions. The RMR is added by any physical activity throughout the whole day, be it work or household, means of transport (e.g. biking to work, walk up stairs, etc) or in form of specific sports activities.

Genetic factors play a role, too, such as the way of energy intake and the composition of our nutrition. All of these factors strongly influence how much energy our body uses and how much energy we need to give it in order to keep our body and its weight balanced.

What do sports people need to consider when reducing their body weight?

Most people wish to lose a lot of weight within a short period of time. For sports people, this is unrealistic and not sensible at all. A negative energy balance increases the risk of losing not only fat mass, but also muscle mass. This has negative consequences for the performance capacity. It has been shown in a scientific study that, with a reduction of the body weight by 0.7% per week, more muscles could be retained than with a reduction by 1.7% within the same time frame (Garthe et al. 2011). The consequences of an excessive energy restriction are not only a decrease in performance, but also reduced muscle force, reduced storages of glycogen or reduced ability to concentrate. It also increases the risk of getting injured due to tiredness or shortage symptoms (bsp. too low bone density, iron deficiency, etc.). You should also not forget about psychological factors such as the emotional state of a person. That is, for an athlete with an existing training programme, it is recommendable not to decrease the daily energy intake by more then 500 to 700 kcal per day.

Another important factor is the protein intake. When reducing your energy intake, you normally also reduce your protein intake. However, sports people are generally recommended to consume more protein (1.4 to 1.7g per kg body weight) on a daily basis than what is recommended for a healthy, inactive person (0.8g per kg body weight). Generally, it can be said that with a weight loss through reduced energy intake, the intake of proteins per day should be increased (e.g. 1.9 to 2.1g per kg body weight). It could be shown (Mettler et al. 2010) that, through a higher protein intake during weight loss, a higher share of the muscle mass is retained. However, the protein intake should be apportioned during the day, in order for the body to always be provided with enough proteins for the forming and reparation of muscle mass. For this reason, it is sensible to talk with a specialist about how to adapt your nutrition to your training.

Very important for sports people is also the timing of the energy intake. Especially for intense sessions, carbohydrates are important in order to achieve an optimal training intensity and qualitiy. Further, the nutrition intake after training is very important for optimal recovery until the next session. It is recommended to never leave out a meal (Manore, 2015), but to adapt the amount and the composition of your food – especially the share of carbohydrates – to your training. You should also be careful to eat enough vegetables and fruit (at least 5 portions a day), so that you reach the recommended amoung of micro nutrients (e.g. vitamins and minerals) per day and that you avoid deficiency symptoms.

Practicle tips:

  • Avoid reductions of energy intake of more than 500 to 700 kcal per day
  • Be aware of a sufficient supply of proteins (at least 1.4 to 1.7g per kg of body weight)
  • Adapt your nutrition to specific trainings (duration, scope, intensity, goal of the training)
  • Eat enough carbohydrates before trainings which have the goal to achieve an especially high quality or intensity (e.g. intervals, HIIT, competitions, etc.)
  • Don’t aim for too high weight reductions without a shor time frame (< 5kg in 12 weeks)
  • Be aware of a healthy and balanced nutrition
  • For athletes with high ambitions, it is recommendable to talk about the adaptation of nutrition to training with a specialist in sports nutrition

At the third annual meeting of the Swiss Sports Nutrition Society , the topic of weight reduction in sports will be treated more closely. Further, a lot of interesting topics within sports nutrition will be discussed by renowned presenters from within and outside Switzerland.


This blog entry was written by sports and nutrition scientist Dr. sc. nat. Joëlle Flück. She works at the sports medical centre in Nottwil and coaches athletes of all levels in terms of sports and nutrition. At the same time, she conducts studies in the area of sports nutrition and is the manager of the Swiss Sports Nutrition Society. As a former middle distance runner she has been able to collect countless medals at Swiss championships. Today, she focuses on longer distances.