GPS Technology used in the TAC Cup
Matthew Glossop
High Performance – Strength and Conditioning
Murray Bushrangers FC TAC Cup
The use of GPS technology in football is rapidly increasing as we seek to objectively quantify the physical
demands of training and match-day. The ability to monitor every second of a training session in real-time,
manipulating individual loads and seeking specific conditioning outcomes is invaluable, while we can use
match-day data to predict and avoid injuries as well as driving rotations. Post-match, sports scientists will
analyse this data and report to relevant coaching and medical staff along with individual players.
While I am far from an expert in this area, I thought I would share with you some of our practices for how
we communicate this data.
GPS Dashboard from a TAC game
How to approach the Coaches and Players
The sports scientist needs to understand his coaching panel and identify how they prefer their data
displayed. Some will want one or two key numbers, some will want the lot while other coaches will prefer
just a brief comment to summarise. You can have the most meaningful numbers in the world and the
prettiest graphs, but if your coaches don’t understand what you’re telling them, they’re useless.
For our playing group I always avoid using the words ‘good’ or ‘bad,’ because high numbers don’t always
correlate to good performance and vice versa. Give them strategies that relate to the game, avoid “we
need you to work harder, I want your high intensity running up,” instead use “let’s focus on getting to more
contests, because the more contests you get to, the more chances you have to influence the game for us.
I’m going to watch you at stoppages, I want you to be the first to leave; this will drive your numbers up.”
What do we look at?
While there are hundreds of parameters available, teams will generally use similar variables (often with
slight variations - velocity bands etc).
Metres per Minute:
How many metres covered per minute played in the
game. This is the primary variable for midfielders and
is an expression of their work rate.
Distance:
Not overly important during match-day (more important
during training).
As you can see to the right, the Half Forward has done nearly
13km, while the Wing has covered 10.5km. But when we
include the time on ground (87% and 66%), we see the Wing
has covered 147m for every minute on the ground, while the
Half Forward has covered 137m. This is why m/min gives us a
better overall indication of work rate.
High Intensity Running:
How many metres (or % of metres), above a certain velocity. A simple set-up is to use velocities relevant to
walking, jogging, running and sprinting (on the left, displayed as % of total metres).
A more absolute way to communicate it, is to look at the total amount of sprint metres accumulated (on
the right).
Max Velocity:
Refers to the maximum speed the player’s hits (for a given
time) during the game. It’s important to realise that often a
player won’t reach his true max speed during match play,
so it may take a few games (alternatively, use data from
training).
As strength and conditioning coaches, we’re often told that
max speed is irrelevant in field sports because our players
never run the 30+ metres in a straight line to use it, but GPS
is showing us that the athletes are rarely stationary and
often they are moving relatively fast before they begin a
sprint effort, allowing them to get to a high percentage of
their max speed in a short distance.
Where this can be interesting (and often validate what the
coaches already perceive), is by looking at the above
graphs, we see that while our Half Forward has put up high
numbers for metres/min (work rate), his sprint metres
(282m) is considerably lower than the Half Back (who had a
lower metres/min). On first glance, it would be easy to tell
him he doesn’t work hard enough to get those high end
metres, but when you look at the max velocities (right), you
start to get a clearer picture.
Assuming these are genuine top speeds, the Half Back only needs to get to 69% of his top speed to start
accumulating sprint metres, while the Half Forward has to work at 82%.
Other Categories
Over the season, I have cycled through other variables such as amount and length of efforts, player load
and accelerations/decelerations to see which ones the coaches would ‘bite at.’
I’ve found some of the most useful ones have been those I have created by mixing the data with game
statistics such as metres per possession. This identified players who may have very high running numbers,
but don’t influence the game because they don’t attract the ball, along with the more ‘efficient’ runners
who tend to run smarter.
Lastly, I will include a brief comment, summarising how I interpreted each individuals physical output. This
usually includes some suggestions on which rotation/quarter he performed best in during the day and
other positions his physical profile may fit.
While GPS data can be enormously effective when used correctly, it is certainly worth noting that above all,
it is a ‘tool in the toolbox,’ and needs the coach to work with his strength and conditioning team to get the
best outcome for each player and the collective group.