SWEEPING PROFILE

Curling events usually last multiple days, with games being played in fairly quick succession. Sweeping requires multiple high intensity physical exertions throughout each game.

It is important to understand the characteristics of these exertions and their distribution, along with the physical demands of sweeping. This allows for athletes to optimise their training, technique, nutrition, and general preparation for curling games, events, and seasons.

In each curling game, each player has a sweeping profile that describes the distribution and nature of their sweeping exertions. The sweeping profile consists of 3 aspects:

Sweeping volume.
Sweeping intensity.
Rest between sweeping exertions.

Sweeping during a game is characterised by successive, short bursts of high intensity exertions. Each exertion is followed by a rest period. These high-intensity intervals are repeated throughout a game when needed to optimise shot outcomes.

sweeping volume

Sweeping volume is the amount of time a player sweeps for, regardless of intensity. Cleaning and maximal sweeping contribute to sweeping volume equally.

During a 10-end game, a front-end player can sweep a maximum of 60 stones, although it is generally fewer, especially with the current single-sweeper strategy. Each individual sweeping exertion ranges from <1 s to ≈25 s. This makes the maximum total sweeping volume in a single 10-end game ≈1500 s [25 minutes].

sweeping intensity

Sweeping intensity refers to how hard a curler is working. This can be measured in multiple ways:

As a percentage of an athlete's maximum power output.
Via rating of perceived exertion [RPE].
Via heart rate.

As exercise intensity increases, the body is placed under greater physiological stress to meet the demands of the muscular contractions. Exercise intensity is often divided into zones based on performance data [Sanders and Heijboer, 2019]. High intensity sweeping intervals require bursts of high power output, with expected increases in RPE and heart rate. These exertions would fall within a high intensity zone.

Different sweeping intensity measurement methods can lead to different interpretations of sweeping intensity. For example, at the end of a game, a fatigued sweeper will likely have a high RPE but be sweeping with a lower percentage of their maximum power.

In a game, sweeping intensity depends upon how well stones have been thrown. Generally, the better a stone has been delivered, the lower the sweeping intensity necessary, since stone trajectory does not need to be significantly impacted. Conversely, stones delivered further from the desired stone trajectory will usually require higher sweeping intensity, with the aim of maximal trajectory alteration.

rest

Between sweeping exertions, there are periods of rest whilst the opposing team plays their shot. This rest period lasts from <30s up to few minutes, depending on how long the opposing team takes to make decisions and complete their shot. During this time, it is important that sweepers can recover as much as possible so that they have the potential to sweep their own teams stones effectively.

Rest relieves the body from stress, characterised by reduced physiological demands. During these periods muscle reoxygenation is greater, phosphocreatine stores can be replenished, and waste products are removed, as the body begins to restore homeostasis [Schoenmakers et al., 2019].

There are other periods of rest for curlers, such as when delivering their own stones. Throwing stones is generally a lower intensity activity than sweeping, allowing for recovery to take place. Teams may also have a 5 minute 4th/5th end break and 1-minute breaks between ends, allowing them time to rest and recover. Also, not every stone requires maximal sweeping exertions. Cleaning a stone, for example, would constitute a level of rest.

In a review of High Intensity Interval Training [HIIT], it was found that longer rest periods [>80 s] result in higher subsequent power output [Schoenmakers et al., 2019]. It was also found that with longer rest periods, the fatigue index was reduced. This means the decline in power output, from the first to the last exertion, was smaller than with shorter rest periods. For curlers, this means that increasing rest durations between intense sweeping exertions will result in improved maintenance of sweeping performance over a game.

implications

Understanding the sweeping profile provides a greater appreciation of the physiological demands of curling. It also informs curlers and coaches on how to best prepare for games and events by optimising:

Training methods - to maximise physiological adaptations.
Technique - to improve sweeping efficacy.
Nutrition - to support performance and recovery.
Rest - to maximise recovery.

Creating a plan to address these variables, based on the sweeping profile, contributes towards evidence-based practice. It ensures preparations are goal-driven and specific to the demands of curling.

summary

The sweeping profile describes the characteristics of sweeping over a game, consisting of:

Sweeping volume.
Sweeping intensity.
Rest between sweeping exertions.

Sweeping volume:

Measure of the amount of time a player sweeps for.
Maximum of 25 minutes over a 10-end game.

Sweeping intensity:

How hard a curler is sweeping.
Can be measured via power output, RPE, or heart rate.
Greater intensity = Greater physiological stress.

Rest:

Allows for the body to recover.
Players can rest during opponent shots, when delivering their own stones, and between ends.
Longer rest periods = Improved subsequent performance.

The sweeping profile can help to inform effective:

Training methods.
Sweeping technique.
Nutrition planning.
Rest planning.

further thoughts

It would be a simple study to analyse the sweeping profiles of curling athletes. Monitoring the sweeping volume, intensity, and distribution, along with the rest periods involved in a game, would be greatly beneficial in better understanding the demands of our sport. With this information, athletes and support teams can optimise training and preparation to best support performance on the ice.

Studies of this nature have been performed in others sports, such as grand tour cycling [Sanders and Heijboer, 2019]. Here, they measured exercise intensity, during different stages, using heart rate and power output data. This could be replicated in curling, with the distribution and intensity of exertions, and rest periods being monitored.

references

Sanders, D. & Heijboer, M. [2019] Physical demands and power profile of different stage types within a cycling grand tour. European Journal of Sport Science, 19[6], 736-744. link
Schoenmakers, P. P., Hettinga, F. J. & Reed, K. E. [2019]. The Moderating Role of Recovery Durations in High-Intensity Interval-Training Protocols. International Journal of Sports Physiology and Performance, 14[6], 859-867. link

SWEEPING PROFILE