Bosco Repeat Vertical Jump
This procedure describes the method for the Bosco Repeat Jump, a variation of the vertical jump test for measuring anaerobic leg power, in which multiple jumps are performed in a set time period. This is part of the Bosco Ergo Jump Protocol. See more about other vertical jump techniques.
- equipment required: Bosco Ergojump System (or similar device - e.g. just jump mat, Myotest, infrared laser system)
- procedure: The aim is to perform the highest number of jumps with maximum height in the set time period. Jump height is calculated using a timing mat which measures the time the feet are off the mat (flight time) and time on mat (contact time). The athlete begins in a stationary position on the mat with weight evenly distributed over both feet. Hands are placed on the hips, and stay there throughout the test. When ready, the athlete squats down until the knees are bent at 90 degrees then jumps vertically as high as possible, and lands back on the mat with both feet at the same time, bending the knees and repeating the jumping action. This series of repeated maximum jumps continues for the set time period. The test time is between 5 and 60 seconds, often 60 seconds.
Several results can be calculated from the test, using the data of the number of jumps, average flight time and contact time, and total time of the test.
- jump height: The height of each vertical jump can be calculated using this formula: jump height = 4.9 x (0.5 x Time)2.
- average power: The average power generated (W = Watts / kg) is calculated from the test duration (Ts from 15 to 60 s), the number of jumps (n) total flight time (Ft ), so that; W = (Ft x Ts x g2) / 4n (Ts - Ft), where g is the acceleration due to gravity (from Bosco et al. 1983). See the table of reference values below.
- fatigue index: to calculate the fatigue over time we can calculate the average every 15 or every 20 seconds in the range (0" - 20"), (20" - 40"), (40" - 60") or fractions 15 seconds, then compare these values over time. Fatigue can also be calculated by dividing the average height of the jumps during the first fifteen seconds with the average height of the jumps in the last fifteen seconds.
Table of reference values for adult male athletes for the 15 and 60 seconds tests.
|Average Power (W/kg)||1
|0-15 seconds||< 25.0||25.1-28.3||28.4-31.6||31.7-34.9||> 35.0|
|0-60 seconds||< 20.0||20.1-23.3||23.4-26.6||26.7-29.9||> 30.0|
from Kuntotestauksen Perusteet, Principles and guidelines for fitness testing, by R. Y. Liite
- advantages: the test provides much more information about lower limb power than a simple vertical jump test for height.
- disadvantages: The jump height is affected by how much you bend your knees, so the test can be invalidated if the subject does not bend the knees the required 90 degrees each time (which is hard to control).
- comments: The subject may benefit from practice, and should be verbally encouraged to perform maximally for each jump. The take-off and landing must be from both feet.
- references: Bosco C, Luhtanen P, Komi PV. A simple method for measurement of mechanical power in jumping. Eur J Appl Physiol Occup Physiol. 1983;50(2):273-82.