The Science


The F&K has the capability to provide both a full Cardio(Aerobic) exercise over a 20-minute time frame as well as providing a full strength (anaerobic) exercise in as little as less than a five-minute time frame.

What really makes this machine so successful, which is proven by the test results, is it allows the athlete to work at the 85% max heart rate (MHR) in a very quick and efficient manner during a rigorous training workout. Most machines such as a traditional treadmill, elliptical, and exercise bike which struggles to get the athlete to that zone and more importantly maintain the desired heart rate.

This is a total body exercise with NO impact which you find with all traditional exercise machines on the market. In addition, the F&K has a full and greater Range of motion (ROM) than any other exercise machine on the market today.

The unit can be used in both the traditional 20-minute cardio training format as well as integrated into the traditional circuit training format that can be used in both the cardio and strength training (aerobic and anaerobic) format.

The F&K is currently being reviewed by NASA for the MARS training program. This is the only exercise machine on the market that can function in a Zero gravity environment that produces both an aerobic and anaerobic effect in a training session. We are in the process of delivering the F&K to TX A&M’s head strength training coach. We are also supporting a Veterans half-way house to aid in the transition to civilian life and the reduction of PTSD by increasing the endorphin’s which will decrease the depression that comes with PDST.


The purpose of this study was to document the metabolic effects of exercising on the Fish and Kangaroo Machine.

Metabolic outcomes were broken down into aerobic (oxygen consumption and heart rate) and anaerobic (blood lactate) effects.

The Fish and Kangaroo machine allowed for simultaneous arm and leg motion while the subject was lying in a prone position. Variable resistance to the motion was controlled by a spring system, which applied 20 pounds of resistance to each arm and 50 pounds of resistance to each leg.

For this study we recruited healthy, physically active adults (men=4, women=6) to perform 6 exercise/rest intervals over a period of 42- min (Interval = 1-min of exercise and 4-min of passive recovery). Oxygen consumption (VO2), ventilation (VE) and energy expenditure (EE) were measured via automated analysis of expired respiratory gas (ParvoMedics). Heart rate (HR) was measured by telemetry (Polar). Blood lactate was measured using a handheld meter (Lactate Plus). With the exception of lactate, all other measures were made continuously. An ANOVA with repeated measures was used to test outcome variables and a P<0.05. Compared to the peak response of the first exercise interval there was a progress rise in VO2 (13%; P<0.0001), VE (17%; P<0.0001), EE (20%; P<0.001), HR (13%; P<0.0001), and blood lactate (50%; P<0.0001) over the course of the exercise intervals.

With the exception of HR and blood lactate, all of the other variables returned to pre-exercise values within 4-min of the end of the last exercise interval. The peak lactate of 10.69±0.72 mmol/L remained elevated at 10-min post-exercise, while HR remained elevated by 20% at 10-min post-exercise.

Further evaluation of these findings demonstrates the current design of the Fish and Kangaroo Machine elicits an exercise response that is primarily anaerobic in nature.


After being approved to participate in the study, subjects reported to the lab between 0800 and 1100 following an overnight fast (≥8h) and abstention from exercise (≥12hr). Following 15-min of seated rest, subjects were fitted with a heart rate monitor (Polar USA), nose-clip, and a mouthpiece to collect expired gases. After 2-min of seated rest, subjects began the first of six exercise/rest intervals. Each interval consisted of one-minute exercise on the FKM, in which subjects were instructed to work at their maximum capacity. The 1-min duration of exercise bouts was determined by the pilot test phase as the optimal exercise duration for subjects that were not accustomed to the FKM. During pilot testing, it was revealed that exercise on this device had a strong anaerobic component and thus the present protocol was designed to examine the effect of short-term, repeated exercise bouts with recovery. Subjects were allowed 4-min of recovery between exercise intervals. Upon completion of the 6th and final exercise interval, subjects recovered for 10-min. The entire duration of the exercise protocol was 42-min.

Cardiovascular Measurements

Mixed expired air was collected and analyzed to determine oxygen consumption (VO2), respiratory exchange ratio (RER), ventilation (VE), and energy expenditure (EE) continuously during the 42-min of testing using an automated metabolic cart (Parvomedics; Salt Lake City, UT). Data were averaged and reported as the mean response at the end of each exercise or rest interval.

Heart Rate

Heart rate (HR) was continuously monitored via telemetry (Polar, USA). Data were averaged and reported as the mean response at the end of each exercise or rest interval.

Blood Lactate

Blood was collected from a fingertip at the following 8 time points: at rest, after each exercise bout (6), and 10-min after the final exercise bout. Measurements were made using a handheld analyzer (Lactate Plus; Nova Biomedical; Waltman, MA).


Cardiovascular Measurements

Compared to the peak response of the 1st exercise interval, VO2 (+13%; F=68.82; P<0.0001; Figure 3A), VE (+17%; F=72.4; P<0.0001; Figure 3B), and EE (+20%; F=75.62; P<0.0001; Figure 3C) were all great at the end of the 6th exercise interval. Generally, these responses returned to resting levels during the 4-min recovery period between exercise intervals. Given that there was no change in recovery length, it is reasonable to speculate that each exercise interval provided a similar amount of exercise stress. We found no significant change over time for the RER (F=0.93; P=0.36; Figure 3D), thus it is reasonable to assume that the ratio of carbohydrate to fat utilization was not altered by exercise on the FKM.

Heart Rate Response

Similar to the metabolic outcome variables, we observed a significant increase in HR from the peak response of the 1st exercise interval to the peak response of the 6th exercise interval (+13%; F=26.28; P<0.0001; Figure 5). The HR response differed from the metabolic outcomes in that the HR did not necessarily return to pre-exercise values during either the rest intervals of the final 10-min recovery period. In fact, at the end of the 10-min recovery period, HR was still elevated by about 20%.

Blood Lactate Concentration

Blood lactate concentration was measured as an index of the relative anaerobic contribution to exercise. As anticipated we saw a progressive rise in blood lactate concentration over the course of the exercise protocol (F=50.73; P<0.0001; Figure 6). The largest increase was between the peak of the 1st exercise interval and the peak of the 6th exercise intervals (+50%). The peak lactate observed was 10.69±0.72 mmol/L, which was approximately 3 times greater than the pre-exercise value (2.90±0.55 mmol/L).