Investigation of power and speed in relation to the increasing instability in a group of untrained athletes and a group of expert athletes. In this way, the effectiveness of unstable training for different types of athletes can be tested.

Our hypothesis is that as instability increases there is a gradual decrease in power and speed of execution, but not too relevant in the expert group.

Introduction

Strength training using devices that induce varying degrees of instability is widely practiced in numerous contexts and has been credited with benefits in prevention, rehabilitation and general health. Several studies have found a progressive decrease in power as the degree of instability increases. However, it is not known how mildly unstable situations are affected, nor are the differences between trained and untrained subjects.

The purpose of the present study was to compare the effect of different degrees of instability on power and speed of execution in a push-up or arm-bottoms exercise, in trained and untrained subjects.

Method

Maximum power (MP) and mean power (BP), and maximum speed (MV) and mean propulsive speed (VA) of push-up were analyzed in 44 subjects, 24 untrained (176.38±5.35 cm, 76.38±6.85 kg, 2.5±1.5 months experience) and 20 trained (178.45±5.91 cm, 83.4±21.56 kg, 15.5±5.3 months experience), under six conditions of increasing instability: 1) stable, 2) device in suspension: rings, 3) monopodal, 4) device in suspension: TRX®, 5) with hands-on Bosu® and 6) with hands-on TRX® and feet on Bosu®.

Inclusion Criteria:

• 2 years of continuous strength training
• No injuries of any kind within the last year
• Perform a regular push-up exercise
• Having ever used an unstable device

Exclusion Criteria:

• Previous injuries
• Never have used unstable devices
• Newcomers to strength training