In the world of endurance sports, the question of which is the hardest is a hotly debated topic. The two-time Olympic champion and multiple-time world champion triathlete, Alistair Brownlee, has taken on this challenge by crunching the numbers and analyzing the data. But is it really that simple? Let's dive into the details and explore the complexities of this debate.
The Data and the Findings
Brownlee and his colleague Halvard Ramstad analyzed a dataset comprising thousands of European athletes across nine activity types. They looked at average heart rate (HR) per session and peak HR per session to determine which sport puts the most strain on the cardiovascular system. The results were surprising.
Running came out on top in terms of average HR per session, with a median of 145. Indoor cycling was close behind with a median of 134, followed by cross-country skiing (131), outdoor cycling (125), and open-water swimming (119).
However, when comparing average HR per session to peak HR per session, running again came out on top. This suggests that runners push their bodies to the limit, maintaining a high heart rate throughout their sessions.
The Nuances of Endurance Sports
But is it really that simple? The truth is, endurance sports are complex and multifaceted. Running may have a higher average HR, but it's not the only factor to consider. As Brownlee points out, running demands more power for what people think of as 'steady' pace, and many runners are stuck in Z2 'semi-tempo' running, which can contribute to higher HRs.
Additionally, the nature of genetics plays a role. We weren't meant to run long distances as part of our evolution, and this can impact the cardiovascular system. HR is still a poor way to measure the actual body impact of a session, especially in athletes over 65 years of age.
The Importance of Intensity and Time
Another factor to consider is intensity and time. While running may have a higher average HR, it's not the only measure of cardiovascular load. Brownlee introduces the concept of 'intensity-minutes', which takes into account both intensity and duration. In this calculation, downhill skiing comes out on top, followed by outdoor and indoor cycling, and then running.
However, Brownlee also points out the limitations of this approach. A linear model ignores the exponential rise in metabolic cost of exercise above the lactate threshold, and recovery cost per minute increases sharply. This means that a straight duration × intensity calculation may not be the most accurate measure of cardiovascular load.
The TRIMP Approach
To address these limitations, Brownlee and his team used the TRIMP (Training Impairment Points) approach, which is described as 'the academic standard'. This approach takes into account the intensity and duration of a session, as well as the recovery time required. According to this method, cross-country skiing comes out on top, followed by running, indoor cycling, and outdoor cycling.
The Coach's Perspective
We asked Joe Beer, a hugely experienced coach who has been coaching cyclists, triathletes, and other endurance athletes for 35 years, for his perspective. Beer agrees that running is hardest on the body due to impact and the nature of genetics, and he points out that running produces more consistent HR data, which can be a quick way to get fit.
However, Beer also emphasizes the importance of controlled HR and steady sessions. He believes that the majority of athletes are not training enough steady sessions because they believe they might be an Alistair Brownlee if only they push enough sessions hard enough. In his opinion, the best endurance sport is cycling, as it allows for easy or moderate intensity, and it's a great way to get fit without pushing the body too hard.
The Final Verdict
So, which is the hardest endurance sport? The answer is not straightforward. It depends on what you mean by 'hardest' and how you measure it. Running may have a higher average HR, but it's not the only factor to consider. Cycling may be the best endurance sport, but it's not without its challenges. Ultimately, the best approach is to find an activity that suits your body and your goals, and to train smart and steadily.
In my opinion, the debate over the hardest endurance sport is a fascinating one, and it highlights the complexities of human physiology and the nuances of different sports. It's a reminder that there is no one-size-fits-all approach to fitness, and that the best way to get fit is to find an activity that you enjoy and that challenges you in the right ways.
