Your Questions Answered
Q. Usage: The G-Trainer is primarily for rehabilitation, right?
A. The G-Trainer is currently being sold and marketed solely as a training tool. Since the original prototypes were installed with partners and training facilities, users have been making claims on rehabilitative benefits they receive from sessions in the machine. The positive feedback has prompted us to conduct more testing on the application of the G-Trainer as a medical and rehabilitation product and Alter-G is pursuing United States FDA 510(k) pre-market notification and international medical device certifications to market the G-Trainer as a rehabilitation and therapy device. But the training and conditioning and injury prevention applications of the G-Trainer are widely documented by current users.
Q. Usage: What is so important about reducing types of impact and cumulative impact?
A. Running and sports that require quick or jarring movement can be hard on the body. When running at high speeds, each foot plant can jar the body with a force up to twice the runner’s actual weight. Over time, with continued impact from these activities, it can begin to breakdown joints, bones, and muscles. These activities increase the risk of impact-related injuries such as stress fractures. If you can reduce impact, you can train longer and faster without the additional risk of impact-related injuries. Alberto Salazar, Director of Nike’s Oregon Project for distance runners, has incorporated the G-Trainer into his runners’ regular training and conditioning programs.
Q. Usage: I just had knee surgery (or hip replacement, Achilles injury, stress fracture, or other lower extremity injury or surgery); can the G-Trainer help me during rehabilitation?
A. The G-Trainer is a great tool to add to a rehabilitation program after a lower extremity injury or surgery. Of course, you should always consult with your physician or physical therapist, but many of them are prescribing the G-Trainer specifically for these applications. Many lower extremity rehabilitation programs stress the importance of becoming mobile as soon as possible after injury or surgery. Unweighting is a natural choice for many therapists and patients because pain or other limitations are often a factor. Because the G-Trainer is comfortable, does not restrict mobility, and allows for natural body movement without the resistance of water or restrictions of a harness, it is quickly becoming the preferred unweighting system.
Q. Usage: My doctor has suggested that I do more aerobic conditioning, but high-impact activities are not an option for my knees, hips, and back. Can the G-Trainer help me get the aerobic exercise I need?
A. Absolutely. The G-Trainer’s anti-gravity technology allows an individual to reduce their body weight up to 80% in precise 1% increments. This means you can exercise and achieve the aerobic conditioning you need, without the full force of impact on your knees, hips, and back. The G-Trainer allows you to easily control and change weight, speed, and incline while you’re exercising, so you can adjust these variables to meet your needs.
Q. Usage: I have difficulty exercising to loose weight because of physical limitations due to being overweight; can the G-Trainer help?
A. It is very possible that the G-Trainer could be a great solution for you. Weight control is highly dependent on balancing the number of calories taken in by the number of calories burned. A healthy diet is key, but exercise is also vital. Unfortunately, obesity-related mobility limitations can make even moderate exercise programs difficult. The G-Trainer allows individuals to reduce their body weight making it easier to begin a regular walking program.
Q. Usage: Is the G-Trainer recommended for patients with neurological conditions (due to stroke, spinal injury, or head trauma) to assist them with gait training?
A. One of the first applications of unweighted exercise was the rehabilitation of patients with neurological conditions including individuals who had suffered a stroke or brain injury. Studies have demonstrated the benefits of this approach for improving gait symmetry and speed.* The G-Trainer allows a reduction of body weight as much as 80% with a zero starting speed and increases in increments of .1 mph.
For patients with these conditions, the uncomfortable nature of a harness system can be an unnecessary strain and patients may not be willing to get in and out of water to achieve unweighting. Clinicians prescribe the G-Trainer because it provides a comfortable, safe, and secure environment for retraining, and it achieves this without compromising gait mechanics.
Q. Usage: Is the G-Trainer safe for older patients to use for strengthening and conditioning? Particularly if they suffer from ailments such as osteoarthritis or inflammatory arthritis?
A. Loss of strength and overall conditioning can lead to numerous health complications and disabilities for older individuals. However, older individuals are often faced with mobility challenges that make exercising difficult. Because the G-Trainer allows them to reduce their body weight, while maintaining balance and natural body movement, it gives them the opportunity to progressively condition while reducing the risk of falling.
Q. Usage: Would my heart rate be different when using the G-Trainer? Will I be able to use heart rate to judge my workload?
A. Yes, you’ll be able to use heart rate to judge your workload. If you’re walking fast or running in the G-Trainer, your heart rate will indicate your workload just as it does with other forms of exercise. However, when you reduce your body weight in the G-Trainer running becomes easier so your heart rate will accurately reflect this by decreasing. To adjust for this and receive a more intense cardiovascular workout you can increase your speed to reach a higher heart rate and caloric burn. Regardless of how much you reduce your effective body weight in the G-Trainer, heart rate can be used to determine how much faster you need to go to achieve the same cardiovascular workout that you’d achieve running at full body weight. In short, you can do the same amount of work (cardiovascular intensity) by just running a little faster, but the impact on your body will be reduced.
Q. Usage: If I reduce my effective body weight during exercise doesn’t that also reduce my caloric burn/metabolic rate?
A. In a recent independent study Dr. Alena M. Grabowski and Dr. Rodger Kram of the University of Colorado at Boulder used the G-Trainer to measure caloric burn/metabolic rate at different effective body weight percentages. They tested various body weight and speed combinations and found that “multiple running speed and weight combinations demanded the same net metabolic power, but resulted in different peak vertical impact and active Ground Reaction Forces (GRFs). Running at faster speeds with weight support decreased peak vertical GRFs in most cases, yet maintained the same metabolic power demand as running at slower speeds with normal weight.”
Put simply, Dr.’s Grabowski and Kram found that running in a weight support system at reduced effective body weight can reduce the amount of calories you burn, but to make up for this difference you can slightly increase your running speed to achieve the same caloric burn without the high impact.
Q. Technology: Is there really such a thing as anti-gravity?
A. Honestly, no. Anti-gravity is just a hypothetical concept that really refers to the common concept of unweighting or body weight support. What we’re really trying to convey is that Alter-G is committed to developing technologically advanced products that enable individuals to improve mobility and health, recover from injury and surgery more effectively, overcome medical challenges that limit movement, and enhance physical performance.
Q. Technology: Is the technology that creates the anti-gravity effect dangerous?
A. No, it isn’t dangerous. The physical lifting force generated by the G-Trainer comes from a difference in air pressure around the user’s body. Normal environmental air pressure is approximately 15psi. The maximum amount of air pressure used in the G-Trainer, if the user chooses to reduce effective body weight at the maximum 80%, is 16.5psi, so the difference is barely discernable. At the maximum air pressure, the user experience feels similar to the pressure against your feet if you were standing in waist-high water, but without the resistance or movement of water.
Q. Technology: Do I need to wear anything special to use the G-Trainer?
A. To produce the anti-gravity effect, a seal is created around the user’s body by wearing customized neoprene compression shorts that a user slips on over their clothing. The shorts are specially designed for comfort and are similar to clothing worn by many professional athletes for compression and support during competition. The shorts allow a user to be zipped into the soft enclosure to create the air-tight environment around their body. Most users find it more comfortable to wear form-fitting running shorts or pants, but the compression shorts used with the G-Trainer can be worn over just about any type of clothing.
Q. Technology: Is it easy to use? Isn’t being zipped in restrictive?
A. People are amazed at how comfortable the G-Trainer is and how easy it is to use. Individuals simply slip on the customized neoprene compression shorts over their own exercise clothing and step into the G-Trainer enclosure. Unlike a pool, they don’t have the complications of getting in and out of water. And harness systems reduce body weight by lifting you up with a harness that can squeeze your upper body in very uncomfortable ways. G-Trainer users have not experienced any issues that have caused them to reduce the time they spend in the machine. Distance runners have done up to 2-hour sessions stopping only because they were ready to end their workout. The touch screen control panel walks you through the steps to get started and change variable settings while in use.
Q. Technology: Can the anti-gravity technology be used with or adapted for any treadmill?
A. No. The G-Trainer technology is an integrated, complete system.
Q. Technology: If the G-Trainer can make the user feel lighter is it possible to make someone feel heavier while working out?
A. No. The G-Trainer is not able to add effective body weight. Only second helpings and too much time on the couch will do that.
Q. Specifications: How is the G-Trainer controlled?
A. The G-Trainer is controlled with an easy to use touch screen control panel that allows users to set variables for weight, speed, and incline. The system can be personalized for each user with saved workouts and calibration information or can be used without logging in to saved user settings. The controls are designed to be easy to use from the start or while exercising. A USB flash drive can be used to save an individual’s information allowing the user to skip the calibration process and track workouts.
When you first step into the G-Trainer, it has the capability of calibrating your weight so that the air pressure system can regulate itself during use to keep your variable settings accurate throughout your workout session.
Q. Specifications: What is the maximum amount someone can weigh to use the G-Trainer?
A. The system is rated for up to a 400 pound individual running. The G-Trainer has the ability for a heavier person to use the machine and we are working to increase that rating. The calibration process takes into account your weight so that any variable adjustments are specific to your size. The only real size limitation for using the G-Trainer is hip size. To produce the anti-gravity effect, a seal is created around the user’s body by wearing customized neoprene compression shorts that a user slips on over their clothing. The shorts allow a user to be zipped into the enclosure to create the air-tight environment around their body.
Q. Specifications: How fast can I run in the G-Trainer and can I turn around in it?
A. If you can run 18mph than the G-Trainer can accommodate you (and the people from the Olympics would like to talk to you.) The G-Trainer speed variables can be adjusted up to 18 miles per hour in forward motion or 10 miles per hour in reverse. Additionally, you can zip into the G-trainer backwards and use a combination of the reverse speed and incline to train downhill. Care should always be taken when moving backwards or exercising downhill.
Q. Specifications: I’m a tall person (or a small person). Will the G-Trainer work for me?
A. There are 3 G-Trainer models to accommodate user size. The smallest user can be 5′ while the largest user can be up to 7’4″ and each size overlaps the smaller or larger size to try and accommodate groups that will be using one machine. For example, NBA teams generally use the large machine as the majority of the team tends to be very tall.