Life Fitness provides more than 300 different cardio and strength-training products to the fitness industry, delivering products that are used in health clubs worldwide. The company employs more than 1,700 people at 12 international subsidiaries and manufacturing facilities, with 186 dealers and distributors in more than 120 countries.
 
As the fitness industry has matured, its annual revenue growth rate has slowed from high, double-digits to low, single-digits. The health clubs and gyms that are the customers of Life Fitness are looking to maximize the use of exercise equipment, which must be easy to install, monitor, move around, and upgrade. The gyms seek new ways to keep their members loyal and satisfied, and to improve total cost of ownership for their workout machines.

“Our biggest customers tell us that their number one challenge today is ensuring that the mileage on equipment is uniformly spread,” says Raj Rao, general manager, Connectivity Systems, Life Fitness, Schiller Park, Ill. “If you have several treadmills on a floor, you’d be surprised how different the usage is of each machine over its life cycle. So you could end up replacing a treadmill earlier than you would have if you had just switched a heavily used unit with one with less mileage. Club owners don’t know when to rotate the treadmills because they don’t know the mileage on them to start with. Then, just to move a treadmill three feet to the left to improve its utilization, the staff has to rewire the network, or possibly take it down for a day or two.”

To address the issue, Life Fitness sought a technology solution that would add value and address a series of needs. First, in order to avoid having cables strewn throughout the workout areas, the solution would need to be wireless.

Secondly, the solution would allow operators to perform installations and upgrades with no downtime of the exercise machines.

“Gyms simply cannot afford to shut down machines,” says Rao. “We wanted to be able to reconfigure machines without disrupting activities in the club.”

The third goal was to help gym customers keep track of their workouts, thereby increasing member loyalty.

Solution found

Enlarge this picture Fig. 1. Block diagram of the MICAz SoP chip.

Life Fitness spent more than a year researching the appropriate wireless technology to address these concerns. The company initially considered a WiFi approach, but decided against it because of power requirements.

“WiFi is power hungry,” says Rao. “Whatever technology we selected needed to have low power requirements because our equipment, such as a cardio machine, is self-powered, only generating power when the user is on it.”

After Life Fitness investigated a number of options, the company finally selected the battery-powered, mesh-networking technology provided by Crossbow Technology.

“Intel’s wireless technology research team recommended Crossbow as a company that was using wireless mesh technologies and a programming protocol that is lightweight, low cost, and with the reliability that we were looking for,” says Rao.

Within each piece of Life Fitness exercise equipment is a Crossbow-supplied PCB called the VIVO board. One of the key hardware components on that board is a Mote, which is a system on package (SoP) chip called the MICAz. Other companies also make similar types of SoPs, but Life Fitness favored the Crossbow solution because of how it addressed the power issue, and because Crossbow’s reputation for technical support during product development.

Enlarge this picture Fig. 2. Block diagram of the VIVO PCB embedded into Life Fitness machines.

“Crossbow offered a system that could be fully battery-operated, and that was a huge requirement for us,” says Rao. “Simple AA batteries will keep the wireless system in the exercise equipment running for several years. This means no messy, costly cabling to deal with. Less wires means that it’s easier to move equipment around, placing it where its length of service is maximized.”

The MICAz SoP on the VIVO board is a PCB-level integration of a microcontroller, a 802.15.4 radio IC, a serial flash, and a 64-bit serial ID chip. The microcontroller used is either Atmel’s Atmega128L or Atmega1281, and the radio IC is Atmel’s 802.15.4 compliant IC, the AT86RF230. The MICAz SoP can connect to external analog or digital devices. For analog connections, there are seven available 10-bit ADCs (though none are used for the Life Fitness application.) For connecting to digital devices there are I2C, UART, and GPIO interfaces.

 The MICAz SoP is part of a daughter board that interfaces to the Life Fitness machine’s VIVO PCB. The MICAz and Life Fitness exercise machine communicate through a serial interface called CSAFE, which stands for Communications Specification for Exercise Equipment. The Life Fitness machine’s CSAFE I/O jack accepts a normal RJ-45 plug wired to a RS-232 cable (although the wiring scheme has no relation to Ethernet). One of the MICAz’s UARTs is wired to the corresponding RS-232 port on the VIVO board.

Enlarge this picture Fig. 3. Crossbow’s wireless network allows gym operators to perform remote over-the-air programming. Any node can be programmed from anywhere there is an Internet connection.

The main power source for the VIVO board comes from batteries or from the CSAFE port. Power management circuitry switches the input power from the batteries or from the CSAFE port. When CSAFE power is detected, the board will draw power from the CSAFE port instead of the batteries. At the same time, the CSAFE power will begin to recharge the batteries. The moment CSAFE power is lost; the power conditioning circuitry will switch back to using battery power. The types of batteries used are either NiMH cells or a lithium-ion cell such that the supply voltage is 3.6 V.

Health club members and staff interface with the functions of the VIVO through a keypad interface. Health club members can use their 4-digit PIN codes to access their workout profiles and goals. The visual interface is done through the display that is already on the equipment.

The hardware solution is accompanied by a software platform that provides radio communications and networking. Some of the equipment is enabled to route messages from one exercise machine to another until the message is received by the gateway. In other words, all the exercise machines in the gym combine to form a mesh network. The Crossbow network has built-in intelligence, reconfiguring itself whenever equipment is moved. As a result, gym operators are better able to serve their members and able to run their business more efficiently.

Another way Life Fitness used Crossbow’s technology was to implement a virtual trainer for gym members. A trainer can set up a workout plan designed to meet a member’s fitness goals. When the member goes to a machine or station, they enter in their PIN code. This then starts a transaction between the machine and the gym’s server, which holds the workout profile appropriate for that specific machine and that specific individual. The system will track the workout and provide the member with a progress report. This approach solidifies the member’s relationship with the health club and contributes to the goal of higher membership retention.

The Crossbow solution also gives gym operators over-the-air programming (OTAP) capability. Any node can be programmed remotely from anywhere. All that’s needed to perform the programming is an Internet connection. This OTAP capability reduces cost, shortens the time needed to set up and provision the network, and makes it easy for gym operators to implement upgrades.

Rao says that the support from the Crossbow team was very helpful. “Crossbow is not too small, and they’re not too big. They are tightly focused in the wireless network area. And they really took the time to understand our business and our issues.”

The results

Photo of Crossbow’s MICAz SoP chip, the Mote.

Initial results of the implementation are promising. With the Crossbow wireless network, Life Fitness customers are better able to manage their equipment. They receive more information about how the machines are performing. This allows them to make better predictions that minimize equipment downtime.

“Now, when we install equipment, we can set thresholds of usage so that when the equipment is used for a certain period of time, we can provision service to it,” says Rao. “We can give our customers a better feel for how often equipment is being used, what time of day it’s being used most, and what kind of settings make the most sense. This gives them a better understanding as to what mix of equipment is driving the most loyal members in a health club. These customer-relationship insights are extremely important.”

For more information email: info@xbow.com