Fit for purpose
Sports wearables were formerly targeted only at semi‑professional and professional athletes. In 2009, European football clubs were among the first to use wearable technologies to measure players’ workloads. Now athletes as well as coaches and trainers use them to optimize performance, monitor health and reduce the risk of injury.
For the vast numbers of people who are interested in recreational sport and keeping fit, and who find inspiration in the Olympic Games motto, “Citius, Altius, Fortius” (faster, higher, stronger), devices and applications incorporating the latest video and body measurement technologies, combined with increasingly sophisticated software, allow them to track personal health and performance.
Several IEC Technical Committee (TCs) and Subcommittees (SCs) develop International Standards for the different components of multi-sport wearable devices including sensors, microelectromechanical systems (MEMS), batteries, voltage regulators and microcontrollers.
They include TC 47: Semiconductor devices, SC 47F: Microelectromechanical systems, and TC 21: Secondary cells and batteries. TC 56: Dependability, covers the reliability of electronic components and equipment.
Marginal gains win medals
In Rio de Janeiro more than 10 000 participants are competing for 306 gold medals across 42 different disciplines, although only a minority of sports make extensive use of data analytics.
For the British rowing team, winning margins of fractions of a second made all the difference in the 2012 London Olympics. In training sessions, the team’s boats are equipped with force sensors, angle sensors and accelerometry to provide individual athlete data as well as data from the hull on the boat’s overall movement. In the quest for marginal gains, “we look particularly at the angles the rowers are rowing through, the stroke length, the forces, the power they’re putting down onto the water and the acceleration of the boat”, said British Rowing’s performance analyst Jack Mercer. Although regulations forbid the use of telemetry during races, the steady stream of data during training can also offer insights about the rowers’ physical state, potentially assisting with injury prevention and aftercare.
The US diving, gymnastic, rowing, BMX and Paralympic track and field teams all use some form of wearable technology to track athletes’ fitness levels. “We are beginning to venture into the smart fabrics and functional textiles area as well”, said Mounir Zok, Director of Technology and Innovation for the US Olympic Committee. The US cycling team wear “smart glasses” during training rides which incorporate heads-up displays inside the goggles and audio technologies to provide riders with performance metrics such as heart rate, speed and wind conditions, cadence, distance and duration. The glasses can also track data on a dedicated smartphone app, and are expected to go on general sale in October.
In Olympic taekwondo, sensors in the protective equipment worn by competitors are used to measure the impact of strikes delivered and to record valid points automatically. When the system was launched at the London Games four years ago, it was limited to trunk protectors and socks. Rio 2016 will mark the first Olympics to feature sensor‑equipped headgear for electronic scoring.
On the right track
The tracking and analysis of data from wearable technology depend on increasingly sophisticated sensors transmitting data to the cloud. Teams in various sports use these data for training and health monitoring as well as for real-time analysis during matches of players’ fatigue index, collision load and distance covered, allowing informed decisions about tactics and substitutions to be made.
Australian football pioneered the use of location-tracking GPS devices in 2004 to record distances run during a match and the speed of the run. Now many top-flight football clubs, including English Premier League 2016 champions, Leicester City, equip players with wearable personalized trackers containing sensors that can collect up to 900 data points per second relating to acceleration, direction, position and the impact of collisions. Rugby has adopted similar technology, with players in a number of international teams wearing GPS units between their shoulder blades to measure speed and distance covered while training and playing, while sensors fitted in players’ shoulder pads can capture data from collisions on the field. In the US, Major League Baseball has also approved the use of wearables during games. American football players in several NFL teams wear monitoring devices for GPS data collection during training sessions and helmets with embedded sensors to measure the impact of hits to a player’s head.
Bill Gerrard, professor of business and sports analytics at Leeds University Business School, says the ability to combine data from wearables with other data, such as tactical analysis of previous games and opponents’ playing styles, would allow coaches to tailor training workloads to individual players.
One drawback to GPS trackers is their reduced accuracy when measuring high acceleration or braking and rapid rates of change of direction. They face a potential challenge from recently developed devices with inbuilt inertial sensors, such as accelerometers, gyroscopes and digital magnetometers.
These small devices can be attached to the lower back or the lower limbs, and have the advantage of not having to be within satellite range, so they can be used in indoors sports such as basketball and netball.
Crossover into consumer market
The increasing popularity of wearable devices has been a major technology trend in recent years. A survey by the American College of Sports Medicine identified wearable technology as 2016’s top fitness trend. Its adoption by the global sports industry will get a boost from the Rio Olympics and Euro 2016.
The IEC Standardization Management Board (SMB) has set up Strategic Group (SG) 10: Wearable Smart Devices (WSD), which is responsible for establishing the terminology, agreed understanding of WSD, market needs and coordination of activities within and outside the IEC. This Group can draw on the expertise and knowledge of several TCs whose work is relevant to this area, among them audio/video, electronic display devices, medical equipment, environmental, safety of electric equipment, semiconductor devices including sensors, electromagnetic compatibility and printed electronics.
A 2016 report by the research and consulting firm MarketsandMarkets said the wearable fitness technology market was expected to grow at a compound annual growth rate (CAGR) of 13,7% from 2016 to 2022, at which point it would be worth almost USD 12,5 billion.
The consumer boom in sensor‑equipped sports equipment reflects the dramatic drop in sensor prices and the advances in technology that make it easier to integrate data from multiple sensors.
Fitness trackers and smartwatches are the most visible examples. Smartwatches are expected to dominate the mass market for sports wearables, as they enable users to receive calls, text messages and calendar alerts as well as measuring heart rates and collecting fitness tracking data.
Wireless sensor technology can also be embedded in sports equipment to measure sporting performance rather than biometric data. For example, sensors fitted inside a football can track its speed, distance, trajectory and rotation, and a wireless sports sensor patch can measure the acceleration and angular velocity of a golf club head.
Multi-sensor wearables with up to nine different sensors, each processing up to 1 000 data samples per second, can provide instant feedback on a tennis player’s biomechanics. Wearable sensors help golfers to track hand and wrist movement in multiple axes, sharing data with a mobile application for detailed analysis. For swimmers, sensors attached to the plastic hand paddles worn during training can transmit data on stroke parameters wirelessly to smartphones or tablets. And a system designed for ski jumpers combines seven inertial sensors on a jumper’s body and one in each ski with a laser scanner to track trajectory, measure aerodynamic forces during jumps and illustrate the effects of small changes in body positioning.
Engineers at University of California, Berkeley, have developed wearable sweat sensors that can be fitted in smart wristbands and headbands to measure metabolites and electrolytes in sweat, calibrate the data based on skin temperature and transmit the results wirelessly to a smartphone or mobile device. The university says “the advance opens doors to wearable devices that alert users to health problems such as fatigue, dehydration and dangerously high body temperatures”.
The popularity of smartphones and wearables has driven down the cost of MEMS devices, including accelerometers, gyroscopes, magnetometers and pressure sensors. Such devices need to combine the ability to process complex sensor data while incorporating power management features to cut power consumption to the absolute minimum to maximize battery lifetime, a critical parameter in wearables.
Protect and survive
As advances in mobile and wearable technology continue to transfer into the mass market for sports wearables, the future is likely to see the increasing incorporation of sensors into protective equipment, and predictive injury analytics will allow teams to better assess and prevent injury risk. Mounir Zok of the US Olympic Committee predicts that flexible forms of smart sensors could be integrated as part of garments or even as patches on the skin.
The massive volume of sensor-based data from sportsmen and women will improve the evaluation of team and individual performances and could be used by sports marketers to engage with fans and enhance spectators’ experiences. Non-professionals and casual keep-fit fans too will have access to ever-increasing amounts of data, including unstructured data such as social media activity, to improve their own performances or compete “virtually” against others.