Kangoo Jumps are a hard boot with a soft inner liner and flexible ankle cuff, similar appearance to in-line skate boots, with two horizontally opposed leaf springs underneath, as opposed to wheels. Kangoo Jumps are designed to dissipate the impact forces experienced through the ankles, knees, hips and back during running or exercise.
PURPOSE: To investigate whether the use of Kangoo Jumps provides a greater cardiovascular improvement, with fewer injuries, when compared to conventional runners in a walk/run program over a twelve weeks period.
METHODS: Thirteen subjects completed a 12-week, 3 sessions per week training program using normal running shoes (NG) (age: 28.8 � 4.7; 75.1� 25.2kg), and twelve participants used Kangoo Jumps (KG) (age: 25.4� 5.3; 67.4� 18.0kg), also for a 12 week period. Peak oxygen uptake (VO2 peak) and ventilatory threshold (Vt) were measured pre and post training program, using a continuous treadmill protocol. All data were analyzed using ANCOVA (= 0.05), using age as a covariant; injury rates were analyzed with Chi-square 2X2 table (= 0.05).
RESULTS: VO2 peak significantly increased in the KG (7.8 � 3.5 mL/kg/min) compared with NG (1.3 � 2.8 mL/kg/min) (p< 0.05). Vt was not significantly different between groups. NG had a significantly greater incidence of lower leg injuries when compared to KG (� (1)= 6.7, p<0.05). A criterion of 1-week missed training was required for all of the 42.8% lower leg injuries.
CONCLUSION: Training with Kangoo Jumps provides an effective means of improving aerobic capacity, and reducing the rate of injury when compared to training with normal running shoes.

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Testing
All participants had their peak oxygen uptake (VO2 peak) measured during week 1 and at the end of week 12. The continuous treadmill protocol started at 4 mph then increased 0.5 mph every minute up to 8 mph, at which point the grade increased 2 % per minute. The subjects stopped the test when they felt they reached their volitional fatigue. All expired gases were collected and analyzed using the Vmax metabolic cart (V6200, SensorMedics Corp, Yorba Linda, CA). Heart rates were measured using Polar Vantage HR monitor (Polar Electro, Finland).

Training
All of the subjects committed to three training sessions per week for a total of 12 weeks; the leader led one session and two other sessions were completed independently. The training program consisted of walk/run intervals, increasing in total duration from 20 to 65 minutes per session. The first session began with a short jog (30 sec) and a 4:30 minute walk, repeated 12 times. The participants' running time and distance gradually increased each week for the entire 12-week program. All subjects kept a training log for the duration of the 12-week program, which provided a monitor of their program adherence and intensity. Recorded in the training log were their heart rate and their rating of perceived exertion (RPE) (Borg, 1975). The data received from the subjects was limited by their honesty and knowledge to self-monitor their performance during their independent sessions.

Statistical Analysis
The data from the treadmill tests were analysed using the SPSS software package. Analysis of covariance was used to determine if there was a significant change in VO2 peak over the span of the training program, co-varying age. A two-way mixed ANCOVA was used to analyse the ventilatory threshold data. � 2X2 contingency tables were used to determine frequency of injuries between the two groups. These data are reported as mean � standard error analyzed with significance set at p<0.05, unless otherwise indicated.

MaxVO2 improvement
The mean pre-intervention VO2 peak was not significantly different between groups (NG 41.06 �1.22 ml � kg � min^-1 vs. KG 43.22 � 2.14 ml � kg � min^-1). However, the mean (�SE) KG VO2 peak significantly increased (+7.8 � 0.97 ml^-1� kg^-1� min^-1) compared with NG (+1.3 � 0.93 ml^-1� kg^-1 � min^-1) (p< 0.05) after completion of the training program. Figures 1 and 2 graphically represent the change in VO2 peak over the training program for the two groups.

a. Pain or symptoms during or immediately after a run;
b. Had pain or symptoms within approximate time span of start of running program;
c. Injury was felt to be related to running;
d. Injury was significant enough to force them to stop running or significantly reduce their running mileage and seek medical attention;
e. Required to stop running for min of 1 week.

Figure 4- Chart of % of injuries between groups
*p<0.05

Ventilatory Threshold (Vt)
Ventilatory threshold is thought to be a measure of the body's inability to maintain exercise using aerobic metabolism, which therefore an increased utilisation of the anaerobic system. As a result, an increase in VO2 at Vt would indicate a greater efficiency of the aerobic system of the subject.
Both groups did show an increase inVO2 at Vt post intervention, with the KG group (2.28 ml.kg.min^-1 increase) demonstrating a greater increase than the NG group (0.71 ml.kg.min^-1 increase). However, results of a two way mixed ANCOVA show no main effect for time or group, or an interaction effect p>0.05.
The lack of a significant change in VO2 at Vt between and within groups may in part be due to the relatively large standard deviation. A larger sample size may have resulted in a statistically significant change, as the few subjects with very large changes in VO2 at Vt may be distorting the data.
Despite the increases in VO2 peak, the intensity of the training may not have been sufficiently high to result in an increase in VO2 at Vt. The intensity of the exercise needs to be high enough to recruit the anaerobic metabolism and so needs to be near the lactate or ventilatory threshold in sedentary subjects. The training level needs to be slightly above the lactate or ventilatory threshold in trained subjects, so the amount of change may have been dependant on initial fitness level.

Injuries
Of the NG subjects, 42.8% suffered lower leg injuries; compared with no injuries in the KG, refer to Table 1, and graphically represented in Figure 4. None of the subjects had previous injuries directly related to an aerobic training program. The injuries that plagued the subjects included:
1. Iliotibial Band Friction Syndrome
2. Shin Splints
3. Ankle sprain
4. Plantar Fascitis

Of the injuries, which occurred during the training program, 3 were unable to complete their goal of running the Vancouver Sun Run; in addition, 1 subject was not able to complete the post treadmill test due to severe injury.
The training program was developed in a manor to minimize the number of injuries incurred from running, if the program is followed carefully. The subjects who were injured during the study may have not followed the program to detail, which may have made them more prone to a lower leg injury. There are also other extrinsic factors that may have caused circumstances for injuries such as worn out shoes, muscular imbalances, or improper biomechanics.
The KG group suffered minor problems associated with the Kangoo Jumps boots. When introducing the Kangoo Jumps to a new user it is recommended by the manufacturer to wear long socks that will protect your skin, above the top of the boot, from abrasion. They also comment that there may be an adjustment period for the arches of your feet to familiarize with the new sensation of using the Kangoo Jumps.

In this study subjects were spending from 30 minutes to 65 minutes in the boots, and there were some minor problems that the subjects experienced. These problems required a decrease in training for maximum 1 session; however, had the problems been identified earlier subjects would not have missed any training. One of the problems included bruising and swelling around the lateral and medial maleolus. This was remedied by wearing a gel sock to provide more padding to subjects with bony ankles. If the problem persisted with the subject, it was recommended to cut out a large foam donut and tape in into place around the maleolus. Kangoo Jumps are currently developing a more improved boot that may reduce the bruising and swelling by using a softer shell boot.
Blisters are a problem with new running shoes and they are also a problem with the Kangoo Jumps particularly with less breathability of the boots. If the blisters are left alone, they may worsen. The best option to resolve the blisters is to purchase long wicking socks that will help remove the moisture away from the skin on your foot, making it less prone to abrasion. Any lubricating cream may also help to reduce the friction when the subject is getting used to the boots.
Kangoo Jumps are able to fit most body types, however people with larger calves may not be able to get a snug fit around the foot and ankle with the boot. If the boot does not fit properly the subject will not be able to maintain long periods of walking or running in the boots, as problems will arise, such as those mentioned above.

Training
The program used for the aerobic training program was developed by sports medicine physicians to safely introduce participants of all levels to the sport of running in preparation for a popular 10 Km road race in Vancouver, BC. The particular level chosen for this study begins with a short jog, followed by a lengthy walk, for a total of 5:00 minutes. As the program progresses week, the run time increases by 30 seconds, and gradually increases the length of the running time once it surpasses 5:00 minutes. In order to gain full benefit from this program it is necessary to maintain movement during the walk segments of each session. While wearing Kangoo Jumps walking is a little more difficult than wearing running shoes, therefore, the walk is more of a walk with a bounce; which may require more energy than using running shoes � which may add to the amount of work performed per session. This may be another reason for an improved VO2 peak in the post-test.