GPS devices in Sport.
It has become common place to see athletes, especially in team sports, wearing GPS devices – usually worn in vests under their shirts. GPS devices record an athlete’s movements using algorithms to calculate positioning information having acquired signals from satellites.
Once we know an athlete has travelled from one position to another, we have a record of distance and the time it took to cover that distance.
If an athlete has run 10 metres in 1 second we know they have run 10 metres per second. If previous to that second the athlete was running at 5 metres per second, we know there has been an acceleration of 5 meters per second (5 m/s^2).
If the athlete then slows from 10 metres per second to 0 metres per second we know the athlete has decelerated.
But why are GPS devices measurements so important?
Deceleration is a point where fatigue is most prone, and it is the point where injury is likely to happen.
If we take into account an athletes body weight, 70kg as an example, and that the athlete has decelerated from 10 metres per second to a stand still we have to take into consideration the effort made to get a weight of 70kg’s to a speed of 10 metres per second, and that the weight of 70kg now needs to decelerate to 0 metres per second.
The strain on muscles and knee joints at these points of deceleration can be massive. This is why players in sports like football can be more prone to knee problems.
We have seen that using GPS data we can work out metrics that help to ascertain the exertion made by an athlete in any given second.
Some of these metrics include distance, maximum speed, maximum acceleration and maximum deceleration.
We can record how many times an athlete accelerated and decelerated in various speed bands demonstrating how hard an athlete performed in a match or training session. This might lead a coach to changing training plans to aid recovery.
Heart Rate Information:
If we include heart rate information with GPS metrics we can build an understanding of how fit our athlete is and how hard they worked in any given session.
As an example, let’s presume an athlete spends most of their time at around, or above, 85% of their maximum heart rate – we know they worked hard and probably need time to rest.
If the athlete takes time to recover from exertions like sprinting in a match, or training session, we know we need to look at their fitness.
Combining Heart Rate and GPS Information:
Combining heart rate information with the GPS information allows us to see metrics such as how fatigued the athlete was when they decelerated from sprints, for example, demonstrating points of possible injury.
Utilising heart rate and GPS information we can also see the effects of training and how well it is, or is not, helping an athlete’s fitness.
If we are over training or under training an athlete it will show in their overall performance giving coaches immediate insights and putting them in a position to make educated changes.
The use of GPS devices in sport gives us extra insight into our athletes, enabling us to have visual representations of efforts made and fitness. The magic of knowing your players!
About the Author: Anadi James Taylor
I am expert in helping sports clubs and universities with their Sports Video Analysis and their GPS Performance Analysis. I developed iSportsAnalysis.com with top sports scientists, coaches and trainers to help maximise training gains and to optimise the performance of athletes and teams.
I have developed an online system that has helped over 120 universities, private schools and clubs to reach their true sporting potential; whether that has been from them using the online video streaming services, the online sports video analysis or the GPS performance analysis, the results speak for themselves! You can find out more at iSportsAnalysis.com.