The X-iser® Machine
 A Unique Tool for the Conditioning Coach, Athletic Trainer & Personal Trainer
 By Dr.Mark J. Smith PhD.

For more than a decade, The X-iser® Machine has been used by professional sports teams for conditioning, injury prevention and rehabilitation.

Because of its small size, it is not unusual for a strength and conditioning coach, particularly one who spends most of his or her time working with top-level athletes, to take a quick look at The X-iser Machine and dismiss it without as much as a second thought.

While many can see the unit providing benefit to a deconditioned individual, such as for use in the home, they typically think it has no place in their weight room. While I would rather that not happen, it is certainly understandable given that the compared reference is the inexpensive and poorly engineered mini steppers, “as seen on TV” and found in the aisles of one’s local Supermarket.

The size of The Xiser ® Machine is where the similarity with the various mini steppers ends.

First, The X-iser® Machine is constructed of aircraft-grade aluminum that can handle well in excess of 400 lbs. (in fact, strong enough to withstand the efforts of professional NFL linemen holding 50 lb. dumbbells!).

Second, the components in the unique hydraulic unit are of the highest engineered quality enabling a few critical benefits. The unit is virtually silent, extremely smooth and, of great importance, provides for a variable resistance that allows the user an unlimited pedal speed. Consequently, the unit is very effective for non-impact Sprint Interval Training (SIT).

“Okay,” I hear you say, “but I can get my guys to sprint up the stadium stairs.” Yes, you can certainly do that, but think about bringing the stadium stairs into your gym or studio that then allows for a series of sprints between other activities while also providing for some very unique training benefits.

The X-iser® provides for a mode of training that few have ever experienced with any activity, let alone using a piece of exercise equipment. This training technique simultaneously strengthens muscles, develops balance and coordination, and improves overall conditioning, all in a closed-chain fashion without impact on the joints.

To help understand how this technique works, imagine the following:

Unique Training on the X-iser®

If you complete a half-squat standing on one leg (approximately a 45 degree range of motion), your thigh muscles will contract as you go down and as you come up. If you then continue these half-squat repetitions without stopping when the leg is fully extended, you will quickly feel significant fatigue and need to stop in a relatively short period of time because there is no rest period for the muscles.

Completing this exercise on both legs over time will lead to a tremendous increase in leg and core strength as well as balance, but would have a limited effect on cardiovascular conditioning.

But imagine being able to complete this exercise at over twice the speed on both legs at the same time! As crazy as completing multiple one-legged squats on both legs at the same time may sound, this is exactly what the X-iser® training does and as a consequence, can dramatically improve leg and core strength, speed and balance, while also improving anaerobic and aerobic metabolic conditioning.

The nature of the hydraulics of the unit allows for a form that produces a "static equilibrium,” high-frequency stepping action that challenges anyone like nothing else.

What actually happens is that the body's center of mass stays level (there is no vertical movement of the torso) while you are stepping (equivalent to completing half one-legged squats); imagine balancing a glass of water on your head while the legs are stepping at a high frequency (an elite athlete can produce 300 + steps in a minute).

What makes this unique is that in order to prevent the body's center of mass from moving up and down, as we normally see with all other stepping activities, both legs have to work equally, against each other, on both the up and down strokes of the stepping action. Consequently, the quads are working concentrically on the down stroke and eccentrically on the up stroke, simultaneously while in opposition.

Compared to actually sprinting on a track, the stepping form focuses purely on the ground reaction force that propels the center of mass upward and forward (training an elite athlete’s hip flexors for a high knee lift is therefore worked separately). So unlike sprinting on the ground, where there is a 50 percent recovery phase for each leg with respect to ground reaction forces, this X-iser® protocol involves a "no recovery" technique that places a tremendous challenge upon muscular strength and endurance.

Further, the rapid pedal movement leads to neuromuscular development which enhances power, speed and agility which, in turn, translates to improved performance and injury prevention.

Additional Benefits of Using the X-iser®

Proprioception, agility, coordination, and balance can be further challenged by moving the feet farther back on the pedals and by adding other activities into the modality, such as a dumbbell curl and press or medicine ball drills using a rebounder or a partner.

Once an individual’s form is polished on the X-iser® Machine, a 20 to 60 second sprint induces significant fatigue, which is magnified considerably when one has the ability to add the upper body exercises such as the dumbbell curl and press.

The ability to be able to incorporate the dumbbell curl and press while using The X-iser® Machine is particularly useful and effective given the research showing that recruiting large amounts of muscle ignites tremendous myokine (chemical messengers) mediated health and performance benefits.

It is also important to emphasize that because the unit responds to the force generated by the user, it is effective for anyone – an Olympic athlete, a child or a deconditioned individual looking to lose weight.

For those that might be concerned about getting a deconditioned individual to engage in SIT, The X-iser® Machine works particularly well because it is both self-paced and self-limiting. By self-limiting, I mean that because of the unique challenge that the “static equilibrium” stepping form brings, deconditioned individuals typically fatigue in their legs prior to maximizing their cardiovascular system.

Consequently, it allows for a progressive challenge to the cardiovascular system as one develops the necessary muscular strength and endurance over time.

While the research supports that, compared to low to moderate-intensity continuous training (LMICT), SIT provides far greater conditioning benefits to nearly all athletes, there is the recognition that there are athletes that need to do some endurance work.

There are also individuals that like endurance work to simply get a good sweat going or for recovery from vigorous workouts. So, while The X-iser® Machine is superb for SIT, it should also be noted that, because of the variable resistance, it works well for nonimpact endurance workouts, while simultaneously challenging and developing the user’s balance and proprioception.

The unit is also great to use for a warm-up to simply get one’s day going or for use prior to a sporting event.

Further, the unit can be used in a backward position for working dorsi flexion range of motion and tibialis anterior development (any shin splints out there?) and for working side flexion of the thoraco-lumbar junction and lumbar spine (accomplished by stepping without bending the knees).

This latter movement can also be done while flexing at the hip which then works lumbar spine rotation and further helps stretch the hamstrings, glutes, and piriformis.

Scapular and core stabilisation are accomplished in a forward prone position and hamstrings, glutes, and core stabilisation in a backward supine bridge position (go to Instructional Videos to see  some of these exercises). It is also possible to introduce a variety of additional exercises due to the unit’s size, portability, and uniquely connected hydraulic system.

Once you have experienced the high-speed X-iser® Burst Training with proper form, you will quickly realize how the X-iser® Machine makes for a fantastic addition to any gym, studio, office or home.

Now, while the unit is used for more than just high-intensity, closed-chain speed stepping, it is the ability to engage in this activity while maintaining a load on both lower limbs that sets the unit apart from anything else available.

Research behind the X-iser®

Invented by the founder of The International Society of Biomechanics in Sports, Dr. Juris Terauds, The X-iser® Machine is a unit that was specifically designed with SIT in mind.

While collecting data as the official Head Biomechanist at the Montreal Olympics in 1976 (he was also appointed to this position for the Moscow Olympics in 1980 as well as the first ever World Track & Field Championships in Helsinki in 1983), Dr. Terauds and his team established that raising one’s center of mass against gravity was the main contributor of energy consumption in running.

Armed with this data, in 1977, while at the University of Alberta, Dr. Terauds and his team of researchers set out to design a piece of exercise equipment that could be used for Sprint Interval Training (SIT) while simultaneously challenging and, in turn, improving balance.

His team of experts included Dr. Hans J. Gros of the University of Stuttgart in Germany, Dr. Iraklis Tsarouchas of the University of Teseloniki in Greece, Dr. Anthony Bauer of Lakehead University in Thunderbay, Canada, as well as Dr. Pierre Garvais of the University of Alberta in Canada.

All stair climbing machines and steppers seen today are a result of this initial work; however, as the units were developed, they lost the critical component of being able to go at high speed for SIT.

Many units also added unnecessary handles that added cost, size and weight and also encouraged leaning and poor posture.

Holding on to these handles with a death grip also took away the balance challenge and, therefore, the development of proprioception (a much needed attribute for athletes and the elderly in particular).

For those that need balance support, The Xiser ® Machine can simply be placed next to a wall or other support.

By only touching the support when needed (as opposed to holding onto handles), balance will be improved. In fact, one of the main benefits of using The X-iser® Machine is improved balance and it develops remarkably quickly in most individuals.

After completing my Doctorate at Colorado State University, Dr. Terauds invited me to join the mission of researching SIT, educating the fitness industry about SIT, and assessing The X-iser® Machine as a means for doing SIT.

It was Dr. Terauds who first emphasized to me the importance of this mode of training. He had observed through the years of collecting sports biomechanics data that, from the athletes he had come to know, the sprinters appeared healthier and seemed to live longer than their endurance counterparts (to read research articles on SIT, go to Downloads).

So in the capacity as an affiliate professor at Colorado State University, one of my first projects was to examine the effectiveness of The Xiser ® Machine for SIT in the laboratory of Dr. Chris Melby, an expert in exercise and metabolism with a particular interest in Excess Post-exercise Oxygen Consumption (EPOC).

After some initial pilot data collection, the research group embarked on a study to compare the oxygen consumption resulting from three, 1-minute maximal effort sprint intervals on The X-iser® Machine, separated by 1-hour recoveries, with 20-minutes of LMICT, also on The X-iser® Machine.

It was found that just three minutes of SIT constituted 74% of the oxygen uptake of 20 minutes of LMICT (a near 7-fold increase on a per minute basis), demonstrating the effectiveness of SIT on the unit for energy expenditure. This was also at a time when we were not incorporating a more upright and effective stepping posture or the inclusion of a dumbbell curl and press, the addition of which dramatically increases the intensity, muscle recruitment, and challenge to the balance.

The initial idea of extending the recoveries to an hour between maximal sprints was so that the exercise would not induce perspiration.

This would then allow people to work out in their usual day-to-day attire and eliminate the need to change and shower, a time factor necessary with more traditional workouts.

Having the machine in one’s office or home along with the effective “extended recovery” SIT program would then provide the most time-efficient, yet effective, exercise program possible.

This approach is also a very time-efficient training solution for the busy amateur athlete; indeed, thousands of individuals have now shown this approach to be very effective.

Interestingly, extending the recoveries between maximal sprints may provide for more than just convenience; it allows for maximal performance in subsequent bouts of intermittent exercise which may be useful for training anaerobic capacity.

It has been shown that following 30 seconds of maximal isokinetic cycling, four minutes of recovery is sufficient to almost completely restore Adenosine Triphosphate (ATP) and mixed-muscle phosphocreatine (PCr) in type I muscle fibers, but not in type II muscle fibers.

It does not take someone long to realize that a true all-out effort is not repeatable with only a 4-minute recovery. Furthermore, this same research study demonstrated that the restoration of ATP and PCr correlated positively with the total work production of a subsequent 30-second bout.

Consequently, the inclusion of training sessions in one’s overall program where recoveries are extended to allow for total restoration of type II muscle fiber ATP and PCr content may improve muscle training for high-intensity performance. A 1-hour (or more) recovery would allow for complete, or at least near complete, restoration of ATP and PCr in type II muscle fibers. The X-iser® Machine provides a convenient way to implement such an exercise protocol.

If you are a Conditioning Coach, Athletic Trainer, Personal Trainer or Healthcare Professional and you would like to share the success and benefits of the X-iser Machine with your Clients/Patients then please apply for details of our Partner Programme


About the Author
Dr. Mark J. Smith graduated from Loughborough University of Technology, England, with a Bachelor of Science in PE & Sports Science and then obtained his teaching certificate in PE & Mathematics. As a top-level rugby player, he then moved to the United States and played for the Boston Rugby Club in 1987-1988 while searching the American college system for an opportunity to commence his Master’s degree.

That search led him to Fort Collins, Colorado, where Dr. Smith completed his Masters degree in Exercise and Sport Science at Colorado State University. He continued his studies in the Department of Physiology, where he obtained his Doctorate. His research focused on the prevention of atherosclerosis (the buildup of plaque in arteries that leads to cardiovascular disease), in particular, using low-dose aspirin and antioxidant supplementation.

As an affiliate faculty member in the Department of Exercise and Sport Science at Colorado State University, Dr. Smith worked extensively with Dr. Loren Cordain, the renowned author of the book, "The Paleo Diet.” As a result of this collaboration, Dr. Smith has had significant experience in helping autoimmune patients improve their condition through diet manipulation. This same diet has also helped individuals lose weight and athletes improve performance. Dr. Smith has also worked extensively as a personal trainer and health consultant and has lectured extensively on the benefits of high-intensity intermittent exercise and Paleolithic nutrition.


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" Xiser is a portable ergonomically correct sprint trainer. This unit can be kept at home or at the office for quick burst workouts that effectively mimic sprint training. It's perfect for the fat-loss lifestyle "

Jade Teta ND, CSCS
Keoni Teta ND, LAc, CSCS

Authors of The New Metabolic Effect Diet



 “World’s best stair climber!”

Paul Chek, CHEK Institute


" I use burst training with every client I have. It is not an option! Everyone gets on the
X-iser day one to experience what a real burst feels like!
The X-iser is an essential part of my celebrity business - Nutrition on Location - and the foundation of my personal training
routine as well! "

J.J. Virgin CNS, CHFI, Ph.D.

Nutrition and Fitness
Expert for:

ABC's Extreme Makeover
Dr. Phil Ultimate
Weight Loss Challenge
Nutrition on Location - Celebrity Fitness Consulting