Trends and prognostic rowing speeds

Trends and prognostic rowing speeds

To begin, we will make a small note about terminology. It is very often the case that rowers and coaches focus too much on boat movement and so very often, talk about: “boat speed”, “how can we make the boat to go faster?”, etc. In actual fact, the rower’s mass is the biggest part of rower-boat system, and our biomechanical models use its movement as the main efficiency criterion, so it makes sense to shift the focus from the boat to the rower, or to ‘rowing’ in general. Indeed, in other sports, nobody says “bicycle speed” or “ski/skate speed”, or “how can I make my running shoe to go faster?”. In these cyclic sports, the athlete sits on top of the equipment and interacts with the environment through it similarly to rowing, and people in these sports talk about “skier/skater speed” or simply “cycling/running speed”. In fact, average speeds of the boat and rower over the stroke cycle are equal, so the “boat speed” is the same as the “rowers’ speed”. Therefore, here and onwards we will only discuss “rowing speed”, unless we are specifically analysing instantaneous boat velocity, which is different from rower velocity inside the stroke cycle.

Analysis of long-time data samples allows to find trends: during the XX century (Fig.1), the average growth of rowing speed in M1x was 0.17% per year and in M8+ 0.15% per year, which means, over a 2km race, the singles became 68s faster and eights 49s faster over 100 years. We compared this to cyclic sports of a similar race duration: in 1500m running, the growth was 0.17% per year – the same as in M1x, and in 400m swimming, it was 0.37% per year – twice as fast, which could be related to more significant progress in technique and participation in that sport (RBN 2005/12).

Analysis of the modern trends of rowing speed since 1993 (after major changes in the Olympic program) shows that the growth is slowing down compared to the previous century: in M1x it became more than five times slower (0.03% = 0.13s per year), and about two times slower in M8+ (0.09% = 0.3s).
The trend of average speed in 13 consistent Olympic events was found slightly positive at 0.06% (0.2s) per year, but only about 6% of the results variation could be explained by rowers’ performance, and the other 94% is related to weather conditions, so prognostic times based on this trend would not be very reliable.
To detect trends more reliably, the data was filtered based on average speed Vav in each event and its standard deviation SD. It was found that the best method was to use only data points within Vav±2SD range, which rejects 1-2 slowest speeds and makes trends the most consistent and reliable (Table.1). This method showed significant differences between events: the fastest growth was found in W8+ 0.43s per year and the slowest - in W4x 0.02s per year.

“Prognostic” or “Gold Standard” times are widely used in rowing practice for evaluation of training and racing speeds, crew selections, etc. Very often World Best Times (WBT) are used for this purpose, but they were achieved in exceptionally fast weather conditions, and usually, winners of World regattas show slower times. Various versions of “prognostic” times were developed in different countries, which differ one from another in the same event, without explanation of the methods, so they look quite subjective. Table 1 presents a more or less objective version of prognostic times of the winners of the next Olympics obtained using the following method: The average speed and its trend were calculated based on data of the winners of World regattas in each of the 13 consistent Olympic events during 1993-2019 filtered within Vav±2SD. The trends were extrapolated to 2020 and prognostic speeds and times were obtained, which were found in the range from 97.1% to 99.0% of WBT. These prognostic times reflect real results in some common weather conditions and their development over the last 27 years.
Concluding, the random nature of the weather and lack of information about wind during World regattas make trends of rowing speed quite difficult to analyse. It is possible to say that within a small degree of probability, average rowing speed grows about 0.06% per year, which means the average race is about 2s faster every 10 years. Different trends were found in various events, and the fastest growth was found in W8+ (more than 4s over 10 years), which probably reflects tougher competition in this event based on wider participation of women in rowing and development of National squads in this event.

©2019 Dr. Valery Kleshnev