AxSys Blog

Speed Zones in Sport

With the use of Global Positioning Systems (GPS) in sport becoming a commonality, data collected and analysed is now more important than ever. GPS companies like AxSys allow  coaches and athletes alike to measure variables such as; player position, speed/velocity, and movement patterns in attempts to further understand physical demands and workloads.

When thinking about speed, it is common place to divide efforts into a number of speed  zones (or bands) for analysis. However, there is much debate and inconsistency when defining these speed zones and associated activity descriptors (i.e. standing/walking, jogging etc.) within and across sports.

In a systematic review conducted by Cummins et al., 2013,  the greatest variations in speed zones were found between sports. For example, a single speed zone (Zone 4) varied from 13 - 14km/h (cricket) through to 14-20km/h (AFL), with the accompanying descriptors ranging from jog through to high intensity run.

Each team sport requires a unique set of physiological characteristics and demands – so, a uniform set of speed zones seems inappropriate and could potentially lead to less than ideal data collected. There is potential however, for the development of standardised speed zones within sports, which would allow easy and consistent data comparison for coaches and athletes.

In the meantime, whilst there is no standardised speed zones and/or activity descriptors for team sports, we at AxSys provide users with a default set of 4 speed zones (Walking: 3-6km/h, Jogging: 6-12km/h, Running: 12-18km/h, Sprinting: >18km/h) while also providing the freedom to modify and customize both speed zones and descriptors to suit indiviuals and teams. We are also currently working on the inclusion of a research-based speed zone archive for specific sports.

What sport are you involved in? What are the speed zones you use for analysis?

In the coming weeks, the theme will continue to be speed zones, with posts on specific sports and the most common speed zones used for each - stay tuned!

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Cummins, C., Orr, R., O'connor, H., & West, C. (2013). Global positioning systems (GPS) and microtechnology sensors in team sports: a systematic review. Sports medicine43(10), 1025.

AxSys GPS Validation June 2017

 After 15-years of elite sport embracing GPS tracking systems, it is evident that there has one limitation to achieving the levels of distance and speed accuracy that most programs desire from such products: that of GPS sampling rates.

AxSys Performance, the latest company to enter this market has effectively solved this dilemma by integrating a high sampling rate GPS module (18Hz) to bring a new level of accuracy to the much-needed sports performance tracking market.

Several validation studies completed in recent years have clearly stated the issues with lower sampling rate systems when it comes to distance and speed accuracy, including:

 

1. Accuracy and reliability of GPS devices for measurement of sports-specific movement patterns related to cricket, tennis, and field-based team sports.

  • Vickery WM1, Dascombe BJ, Baker JD, Higham DG, Spratford WA, Duffield R.
  • J Strength Cond Res. 2014 Jun; 28(6):1697-705. doi:  10.1519/JSC.0000000000000285.

“Based on these results, practitioners of these devices should be aware that measurements of distance and speed may be consistently underestimated, regardless of the movements performed.”

2. Accuracy and reliability of GPS devices for measurement of movement patterns in confined spaces for court-based sports.

  • Rob Duffield a, Machar Reid b, John Baker c, Wayne Spratford c, a School of Human Movement Studies, Charles Sturt University, Australia b Tennis Australia, Australia c Australian Institute of Sport, Biomechanics & Performance Analysis Department,
  • Received 18 February 2009; received in revised form 23 June 2009; accepted 21 July 2009

“In conclusion, for court-based sports or movements in confined spaces, GPS technology under reports distance covered and both mean and peak speed of movement.”

3. The validity and reliability of GPS units for measuring distance in team sport specific running patterns.

  • Int J Sports Physiol Perform. 2010 Sep;5(3):328-41.
  • Jennings D1, Cormack S, Coutts AJ, Boyd L, Aughey RJ.

“Current GPS systems may be limited for assessment of short, high speed straight line running and efforts involving change of direction. An increased sample rate improves validity and reliability of GPS devices.”

AxSys GPS Validation Results:

AxSys Performance recently completed our first validation study based on our new AxSys GPS (18Hz) GPS unit.

The study, completed by Jocelyn Mara from the Sports Studies Department at the University of Canberra, indicates that the integration of a higher sampling rate GPS module (and associated architecture to deal with higher sampling rates) has effectively removed this accuracy limitation.

Reliability Analysis

To determine the inter-unit reliability of the GPS for distance and maximum speed measurements, the typical error (TE), typical error as a percent of the mean (TE%) and the Intraclass Correlation Coefficient (ICC) were calculated (Hopkins, 2000). The typical error was calculated as the standard deviation of the difference (between GPS 1 and GPS 2), divided by the square-root of 2. The ICC measured the level of agreement between the values derived from GPS 1 and GPS 2. A weighted Kappa correlation coefficient was used to determine the inter-unit agreement for detecting accelerations >2.5m/s2 (Altman, 1999).

Results:  The difference between GPS and criterion values for distance and maximum speed measurements

Difference

Distance (m)

Maximal Speed(m/s)

Mean ± SD -1.56 ± 2.70 -0.02 ± 0.14
Abs. Mean ± SD 2.35 ± 2.04 0.10 ± 0.09
Range (min – max) -10 to 4 -0.3 to 0.3
% Difference -1.57 -0.35
Abs. % Difference 2.37 1.38


% Difference = the difference expressed as a percentage of mean values (GPS and Criterion); Abs. = Absolute values reportedData are expressed as the difference between GPS and Criterion values (GPS minus Criterion);

The above table shows the difference between the GPS measurements and criterion values for distance and maximum speed. On average, the GPS device underestimated distance by only 1.57% and underestimated maximum speed by only 0.35%, resulting in very acceptable levels of accuracy for these measures.

Conclusion:

This early research has demonstrated that Sport GPS systems should embrace higher sampling rate GPS modules such as that used in the AxSys GPS product, otherwise risk under reporting of true distances and speeds achieved by the athletes using these products. 

AxSys All Areas: Wi-Fi Download

AxSys All Areas provides additional insight into the AxSys technology that is unique to the market and sets us ahead of the competition.

AxSys GPS units track and collect large amounts of data during training sessions and games. However, traditional wireless methods of downloading (Bluetooth or Infrared) are ineffective to download the large amounts of data captured. Instead, the AxSys GPS units use high speed Wi-Fi to download the data from the unit to the App quickly and seamlessly. No cords or wires are needed to connect the GPS device before you can access your data.

Additionally, we have built our android Team App to automatically download data from multiple units at once. There is no limit to the number of units to be downloaded and no need for a docking station or cradle to download the data and generate reports.

This seamless integration from data capture to data download is unique to the AxSys products allowing athletes and coaches to focus on what really matters.

For more information on the AxSys GPS units head to our website or try it for yourself and purchase your very own today.

In Case You Missed It …

Summary of Adrian Faccioni’s Keynote Presentation: Utilising Wearable Tech for Improved Outcomes – 2017 ESSA Business Review

With the recent boom in wearable technology, there has been an influx of cheap and easy to use products (such as the Fitbit and Garmin ranges) and a subsequent demand for them. Predominately taking watch form, current wearables are taking advantage of the ‘timeless’, well-worn watch culture (pun intended) to provide convenient and fashionable activity monitoring. However, with wrist based wearables often comes significant accuracy/reliability issues that are now seeing a plateau in product uptake.

Firstly, collecting data based on wrist movement often does not provide an accurate or reliable indication of what the body has been expending or what activity it has performed as a systematically functioning unit.

Secondly, wrist wearables currently place emphasis on numbers rather than answering crucial questions about performance or activity. Capturing a range of biometric data such as steps, heart rate, stairs climbed, and time spent sitting, standing and walking are not necessarily the most accurate indicators of one’s activity or workload.

Lastly, activity measurement is dependent upon a field of computing known as ‘Pattern Recognition’; a technique focused on evaluating patterns in data and trying to match unknown patterns with known activities. Although a revolutionary concept in itself, the patterns that are evaluated vary greatly between individuals and activities, which gives rise to a number of reliability/validity issues. Additionally, a major flaw of wrist wearables is the generation of steps or ‘activity’ with a simple swing of the arm – leading to inaccurate data collection and load monitoring.

So, let’s assume we can progress wearable technology to provide reliable and valid data. Apart from counting steps, how can we quantify an individual’s workload/activity to provide useful information that informs decisions about future exercise routines?

Basically, the question we are trying to answer is;

How do we get wearables to a point where they are customised to YOU; the weekend warrior, the aspiring athlete, the proven champion?

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At AxSys Performance we possess deep pride in our product’s ability to provide simple and personalised analytics alongside an expansive mobile app that serves as an Athlete Management System.

With near-future plans to incorporate additional biometrics (i.e. heart rate) into our technology, AxSys Performance will open doors to both individualised athlete monitoring and remote coaching abilities.

 

 

AxSys All Areas: Capacitive Touch On/Off

Welcome to the first post for AxSys All Areas. These feature posts will provide an additional insight into the AxSys technology that is unique to the market and sets us ahead of the competition.

The capacitive touch On/Off technology in the AxSys GPS units is unique in the market as it ensures there are no moving parts. Moving parts in a unit that is used repetitively in high-paced and /or impact sports can be prone to damage, and reduced or eliminated functionality.

In addition, no moving parts means the unit does not require any plastic or rubber which would make it very difficult to achieve waterproofing. That’s right. Our units are waterproof. Because of the capacitive touch on/off button and the fact our units are ultrasonically welded means the AxSys GPS is the only unit on the market that is 100% waterproof.

And there’s more.

When developing the AxSys GPS units, it wasn’t just about ensuring functionality it was also about surviving general wear and tear. Let’s face it – these units have to survive the same game as you do. With no moving parts, there is no chance of the On/Off button sticking, breaking or just all together not working.

For more information on the AxSys GPS units head to our website or try it for yourself and purchase your very own today.

Am I training specific to my sport?

When it comes to training, there isn’t a one size fits all solution. What works for some athletes may not work for all athletes, which is why it is necessary to make sport specific adjustments for different types of players.

 

If you have read our previous blogs you will know that training in your Sweet Spot will maximise performance and minimise your chance of injury. However, if you are not training with the right methods then it won’t matter that you are training in your Sweet Spot. 
Incorrect training will stagnate performance and potentially limit your maximum potential.  Spending too much time performing aerobic training when your sport is largely speed and endurance focused or excessive weight training in the gym when speed and power should be your focus are good examples of this.

The challenge with training specificity is that it changes depending on your training age (i.e. how many years of serious training you have completed to date), your chosen sport, and the time of season (in-season, pre-season, preparation phase).

Training effectively

The first step to training effectively is to monitor what you are actually completing during each training session. The AxSys GPS system captures training time, distance, high speed running and body load (the physical demand placed on the body through accelerations, decelerations, impacts, etc.).

Once this information is recorded the next step is to compare your training loads and intensities to well documented training data from different performance and age levels within your sport. At AxSys Performance, we have collated 1 000’s of hours of training data to provide each client with specific advice on their training load and effectiveness.

Understanding the data/results

AxSys understands that you’re most likely not a sports scientist and as such don’t want or need to be bombarded with hundreds of figures and metrics that mean very little. Instead we have identified three key questions to be answered at the end of every training session:

  1. Did you train hard enough today?
  2. Are you training specific to your sport?
  3. Are you at risk of injury through under or over training?

The AxSys GPS system has been designed to provide you with these answers at the end of every training session, week or cycle. If you want to look deeper into your performance data we have provided web access to your own personal training database allowing you to view session by session, second by second of all the most important performance metrics.

Let’s look at an example…

As a soccer player, you feel that your endurance isn’t up to scratch compared to that of your competitors. You then start adding additional long runs to your training program which results in rapidly increasing your SLR (potentially to an overtrained state) as well as beginning to reduce your overall speed and acceleration capacity which are key to your ultimate success in your sport.

Luckily, the AxSys GPS has recorded this information and identified the problem. Instead you should be completing field specific endurance training, such as repeated intervals with and without a ball with short recoveries to simulate the demands of the game.

Finally, to maximise your performance it is important that your training program is challenging you over time. The SLR and sports specific analysis tools have been designed to ensure you are following typical training load and performance increases over time. Comparisons of your performance with peers or even the most elite players in your sport will allow you to see where your strengths and, in particular, weaknesses are in order to target these areas for better long term performance.

If you would like to find out more about training specific to your sport, visit our website at www.axsysperformance.com or contact Adrian on 0417 290 854 to see how AxSys GPS can work for you.

How do you know if your injured players are ready to return?

 

When an athlete injures themselves one of their main concerns is how long they have to wait until they can play again. However, each injury and each athlete is different and will require a unique exercise program in order to transition back into a full training schedule and eventually game competition. In the past 10 years some great research on the underlying cause of common sporting injuries in athletes has shown that high training volumes and/or intensity increases the risk of injury, particularly:

  • excessive high speed running increases the chance of hamstring injuries;
  • excessive rapid acceleration training increases the chance of hip flexor injuries; and
  • excessive jump training increases the chance of shin, ankle and knee injuries.

The challenge for sub-elite athletes is typically their technique is not yet robust and as fatigue sets in, their technique changes further increasing the risk of injury in certain muscle groups.

Measuring risk of injury

It's possible to apply several standard principles to assist athletes ease back into training and prevent further injuries.  These principles include:

  • Maintain your Sport Load Rating (SLR - training Sweet Spot) between 80 and 130.
  • Acknowledge that rapid increases in total intensity in a given period is a sure fire way of increasing injury risk.
  • Avoid high intensity training two days in a row – for example completing heavy weights exercises or high speed training on consecutive days. Also try to have 2-3 days between plyometric (jump) training.

Returning from Injury

Following injury, it is very important that the athlete gradually resumes to full training and 100% effort over a structured training period. The AxSys GPS system can assist in guiding athletes back to this stage and ultimately achieve full competitive performance again.

When athletes or coaches do not measure performance it is difficult to know if the athlete is running at 70% or 80% which can be the difference between a successful comeback from injury or re-injuring themselves because they came back too soon. By using the AxSys GPS unit, the player is able to track every step taken, ensuring that training loads and intensities are progressed at an appropriate rate until the athlete is able to perform at 100% without fear of re-injury.

The SLR is a useful indicator for athletes returning from injury. A low SLR means the athlete has not exposed themselves to a full training load that would be expected in a game environment. The athlete must return their SLR to a value above 80 to ensure their body has been appropriately exposed to the demands of their sport and typical injury risk movements (sprinting, jumping, etc.). Extensive research has found that underpreparing an athlete who is returning from injury and then placing them in a competitive environment will dramatically increase the incidence of re-injury. For example, a soccer player returning from a hamstring injury who has not performed adequate sprint and acceleration training leading back into game competition is more likely to re-injure their hamstring when required to sprint repeatedly during the game.

Athletes at all levels should take great care when returning from injury. Decisions regarding training schedules that are too strict, too lenient or too arbitrary can lead to inadequate recovery and preparation causing further delay in returning to competition. AxSys Performance has designed a unique system that uses key metrics to determine the performance and readiness of an injured player returning to competition.

For more information on injury management visit www.axsysperformance.com, or call Adrian on 0417 290 854.

 

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References:

Peter Blanch & Tim Gabbett. Has the athlete trained enough to return to play safely? The acute:chronic workload ratio permits clinicians to quantify a player’s risk of subsequent injury. Br J Sports Med 2016;50:471–47.

Ever wondered what makes AxSys Performance different?

With so many new technologies developed each year focused on improving athletic performance, it can be hard to know what actually works and what will be right for you. 

 

We have developed our products with the athlete in mind. This doesn’t mean just elite athletes; AxSys Performance provides an elite product at a consumer price so all athletes from any age and any stage can use our sport performance system.

So what makes us different?

Professional level of analysis, but at a consumer price

For just $299* per year, the AxSys unit measures total distance, high speed running, and the physical demand placed on the body through accelerations, decelerations, impacts, etc. This is all summarised into one simple score, your Sport Load Rating (SLR).

Easy to understand the data

You don’t need a sport science degree to understand and interpret the data. Information is easy to read at the end of a recorded session or when comparing sessions over time.

Individual and Team capability

The AxSys units and app can work individually or in a group/team environment. So whether you want to monitor your own performance or you’re a coach that wants to ensure your players are in peak condition, AxSys has the technology to suit both functionalities.

Instant results

The data from a session or game is available within minutes of finishing, right to your phone or tablet through your AxSys app. 

We provide answers, not more questions

At the end of every session we provide the answers to the key questions important to all players:

  1. Did I train hard enough today?

    Did I put in the effort that will improve my performance?

  2. Am I at risk of injury?

    Did I do too much in that session? Should I train at a reduced load next session to ensure I don’t over-do it?

  3. Did my training compliment my position and sport?

    Was my training appropriate for my goals and specific to my sport?

And if all that doesn’t convince you? Why not try if for yourself by downloading the free AxSys app available on the App Store and Google Play. By using your mobile device during training sessions you are able to get many of the benefits of regular GPS and performance systems but for free!

 

*Price based off an individual user subscription on a 2 year contract.

Welcome - AxSys SLR App

Congratulations on taking the first step in taking control of the management of your training performance. The AxSys SLR App has been designed to monitor your training loads and intensities with a focus on providing you with a daily Sport Load Rating (SLR) score. 

Your SLR score is based on the latest research on training loads, performance improvement and injury management. At the end of every training session your SLR score will provide you with immediate feedback on your performance for that day by answering two key questions:

  1. Did you train hard enough today?
  2.  Are you at risk of injury from over or under training?

By using the key indicators for injury management (Total Distance Covered, High Speed Running Distance (>18km/hr) and Body Load (the sum of all your accelerations, decelerations, jumps and impacts) AxSys is able to find your training “SWEET SPOT” indicted by your SLR score. 

If your SLR is <80 or >130 then this indicates that you are putting yourself at risk of injury. 

<80 means you are not training hard enough and you may put yourself at risk of injury during game day or if you are competing in a tournament with multiple days of games, whilst a score >130 means you are training too hard compared to previous sessions putting you at risk of an overtraining injury.

If your SLR score at the end of each session is b/w 80-130 then you are training in your “SWEET SPOT” which will maximise your chance of performance improvement and minimise your chance of sustaining an injury.

AxSys would also like to record your view on how hard you found the session – this rating is achieved by providing a score between 0-10 as part of your RPE score (Rating of Perceived Exertion) just prior to uploading your session for analysis. RPE has been shown to be a valid measure of training load for team sports and the combination of the SLR and RPE allows AxSys to better customise our feedback to you.

To help you with understanding the RPE score – see the scale below:
Score  Description
 0. Nothing at all
 1          Very Light
 2          Fairly Light
 3          Moderate
 4          Somewhat Hard
 5          Hard
 6          Very Hard
 7          Very Hard
 8          Very Hard
 9          Very Very Hard
10        Maximum 

Want to know more – Click Here for a more detailed explanation of your SLR score.

ACUTE:CHRONIC RELATIONSHIP

If we use total volume as the key metric to calculate the ACUTE:CHRONIC Relationship – the following ratios are of importance.

  1. A ratio below 1.0, suggests the athlete is likely to be in a state of “freshness” with the load over the past week less than their average weekly load over the past four weeks.
  2. A ratio above 1 represents the workload over the past week has been greater than the average weekly load over the past four weeks, so they may be more likely to be in a state of “fatigue.
  3. Recent research has suggested a ratio greater than 1.3 represents a “spike” in workload that is related to a significantly higher risk of injury (Blanch and Gabbett, 2015).

Training within this ratio range is often described as the “Sweet Spot” for training loading.

A recent article in the British Journal of Sports Medicine (BJSM) has proposed the issue of players in team sports especially not being exposed to game demands (eg high intensity running) in the off season and preparation phase and then using High Speed Running (HSR) as a metric in-season resulting in players being predisposed to injury. Also specifically looking at different metrics (distance vs HSR) to create acute:chronic ratios and examining preparedness highlights the evolution of using data to firstly plan then hopefully predict issues occurring.

Another BJSM paper* looked at a number of variables with the focus on distance >24km/hr in Australian Rules Football and hamstring injury. There existed a relationship between injury and 4 week averages of HSR versus 2 year averages and what seemed lower incidence if a “light” HSR week was introduced once every 4 weeks highlighting the importance of building a training load periodization model into your training programs, both pre-season and in-season.

* “Effect of high-speed running on hamstring strain injury risk BJSM 2016 Gabbett et al “