About Alter G

The G-Trainer anti-gravity treadmill is much more than an exercise machine. It enables individuals to reduce their effective body weight for health and medical applications, to reduce the risk of injury, and to expand athletic training and conditioning programs.

Professional athletes, top collegiate programs, and rehabilitation and training clinics across the US are experiencing the unique benefits of walking and running at reduced body weight.

Since the original prototypes were installed with partners and training facilities, individuals have been making claims on the benefits they receive. When adding the G-Trainer to general conditioning, cross training, and performance enhancement routines, individuals at health clubs to elite athletes report measurable increases to their fitness goals. Rehabilitation clinics and other medical facilities see faster recovery times and lower overall costs for patients. Clinicians are also prescribing the G-Trainer to improve mobility with neurological patients, increase exercise options for patients with weight control challenges, and improve overall health of older individuals.

Everyday we hear from physicians, healthcare specialists, athletic trainers, athletes, and other individuals about why and how they're using the G-Trainer.


Injury Prevention

Whether you’re a world-class athlete or a weekend golfer, it’s always preferable to prevent injuries rather than having to recover from them. The G-Trainer allows individuals to increase training volume and speed while minimizing the risk of impact-related injury and continuing training regimens without pain caused by chronic damage.

With extended variable options that can be adjusted while in use, the G-Trainer meets the needs of any individual. And because it offers unrestricted mobility, natural body movement, and a full range of motion, unlike pools or harness systems, it’s easy for anyone to use.

Recovery Workouts

Many runners use the practice of recovery runs for a number of reasons, including improving blood flow to muscles that have microcellular tears and clearing lactic acid. After periods of intensive training, the G-Trainer offers productive recovery runs because the reduced impact on the body allows the athlete to run longer and faster than traditional recovery runs on hard surfaces at a slower pace. The user experiences a stronger cardiovascular workout while their muscles are healing.

Chronic Injury

Chronic injury issues often plague athletes making it difficult for them to effectively condition muscles or train at competitive levels. When injured or experiencing chronic pain, individuals tend to guard against pain or discomfort, which results in the injured area not receiving the proper developmental conditioning. Additionally, complementary or adjacent muscles receive unwanted development puttin the body at even more risk for further injury. With the G-Trainer individuals experience unrestricted mobility allowing them to maintain a normal gait, stride length, leg kick, and body positioning at reduced body weight so their injured area is undamaged.

Training During Injury Recovery

Whether recovering from sprained ankles, hamstring injuries, stress fractures or more serious injuries, the G-Trainer allows a person to continue doing cardiovascular workouts and conditioning muscles during their recovery period. Because the G-Trainer offers extended variable options with a broad variable range, it can meet any training, conditioning, or therapeutic need. By exercising at a reduced body weight, an individual can receive a normal cardiovascular and muscular workout without pain or risk of worsening their injury as they heal.

Training Through Pain

Painful issues such as plantar fasciitis often force athletes to stray from normal training routines. Training through such pain means their normal gait, stride length, leg kick, and normal body positioning can be compromised. Because the G-Trainer offers unrestricted mobility, individuals can stick to training schedules, and receive a normal cardiovascular and muscular workout without pain or compromising natural body movement.


Overspeed Training

The G-trainer is the perfect tool for overspeed training. As the individual decreases their weight they're able to increase their speed beyond what they could normally do at full weight. They are able to run at a faster turnover rate increasing their body's familiarity with higher speeds. The muscle memory from these increased speed sessions increases the overall speed potential of the individual when at full body weight. The G-Trainer's broad variable range for weight, speed, and incline allows people to customize their workout session to their specific needs.


Long Distance Training

Long distance runners can only run so many miles before the stress of impact takes its toll on their bodies. When they push their limits running outdoors or on conventional treadmills, the risk of stress fractures and other common running injuries significantly increases. G-Trainer users are able to increase their training volume (reportedly up to as much as 40%) by spending some of their training time running at reduced body weight.

Because the G-Trainer allows for a full range of motion, runners can experience a full stride, as they would on a track, with no upper-body restrictions. More miles means better conditioning with fewer impact-related injuries.


Conditioning Specialists are finding that athletes are seriously benefiting in the area of "regeneration" on the G-trainer. Athletes with intense training regimens have to deal with tired legs. With the G-Trainer, they're able to keep up high-quality workouts simply by reducing body weight percentage. The athlete is able to maintain scheduled workouts, regardless of energy state, without the wear and tear they'd get on a traditional treadmill or on the court or field.

Warming Up

With the G-Trainer's extended variable options and ability to adjust settings while in use, athletes can tailor warm up sessions to their specific needs. Individuals can warm up by walking downhill or at an incline. Lowering effective body weight means they're able to warm up without jarring cold muscles and joints.


Cooling Down

The importance of a proper cool down is well-known to any type of athlete. In the G-Trainer, a person can start their cool down at an active speed and/or incline by reducing their body weight then slow down and decrease incline while increasing body weight. This means the individual can cool down at a steady pace with normal body movement even when they're tired after a hard workout.


Interval Overload Training at Higher Running Speed

Control of body weight also provides a means for interval overload training (interval training) in which you achieve a fast speed while at reduced weight and then introduce body weight briefly to overload the musculoskeletal and cardiovascular systems. Interval training is the most rapid method of achieving performance gains, and the ability to tailor and optimize the interval profiles determines the ultimate limit of performance. In the past, this type of training was difficult at best. The G-Trainer provides easy access to this time-tested training.

Training for Proper Gait Mechanics

Traditional methods of unweighting—harness systems that restrict the upper body and pools with water resistance that creates drag on the limbs—interfere with gait mechanics. The G-Trainer is the first unweighting system to provide a nearly unencumbered running experience. This is particularly true for late stance phase mechanics when the hamstrings are acting as decelerators. Water resistance in a pool causes viscous drag which interferes with the free swing phase, but the G-Trainer provides unrestricted forward movement of the limb. The hamstrings are activated in their normal motor pattern, decelerating the leg and foot in preparation for heel strike.


Tempo Runs and Interval Training

The G-Trainer offers extended variable options. Adding reduction of body weight to traditional treadmill variables of speed, distance, and incline allows for more effective and sport specific interval training programs.


Recovery Workouts

Many runners utilize the practice of recovery runs for a number of reasons, such as improving blood flow to muscles that have microcellular tears from intensive training. After periods of intensive training, the G-Trainer offers productive recovery runs because the reduced impact on the body allows the athlete to run longer and faster than traditional recovery runs on hard surfaces at a slower pace. The individual experiences a stronger cardiovascular workout while their muscles are healing.

Training and Conditioning

Elite athletes and weekend joggers alike are always looking for technological advancements to help them run farther, faster. The G-Trainer is being adopted by athletic trainers, conditioning specialists, and exercise facilities to augment training and conditioning routines, enhance performance, and provide the most advanced option in reduced-impact exercise.


The G-Trainer may have application in the following:

  • Rehabilitation: Lower Extremity Injury or Surgery

  • Aerobic Conditioning

  • Weight Control

  • Gait Training for Neurological Conditions

  • Strengthening and Conditioning for Older Patients

Health and Medical

For many years, studies have shown that physical activity has a direct impact on the state of your health, but physical activity can be restricted by medical conditions that limit mobility. The G-Trainer allows individuals to improve overall health, benefit from exercise regardless of many conditions that limit mobility and weight-bearing activities, and rehabilitate more effectively, with less pain after lower extremity injury or surgery.

The G-Trainer is comfortable and easy to use. It allows individuals to concentrate on natural body movement without the restrictions of a harness or resistance experienced in a pool.


Precautions for Use

Always consult a physician before beginning any exercise or therapy program.

  • Cardiovascular disease or respiratory compromise

  • Exercise induced asthma or angina


Contraindications for Use

Always consult a physician before beginning any exercise or therapy program.

  • Acute and chronic back problems

  • Ruptured/Herniated/Bulging discs

  • Unstable fractures and joints