Use of Bands in Squat Performance and Benefits
Force-speed relationships muscle indicates that the increase in the rate of shortening causes a decrease in the production of force, and vice versa. Put simply, if you want to develop maximum strength, you can not do it very quickly, and if you want to do something very fast, you will not develop much strength. However, in sports where the qualities of strength and speed are related to performance, it is necessary to find a good compromise to produce a significant force as quickly as possible (Fig. 1). For an athlete with a high level of force may be unable to develop a major force in a very short time.
It is then necessary to drive these two kinetic variables together with the goal of improving explosiveness (not to be confused with the power). The explosion or rate of force development (RFD, N · s-1 or N · m · s-1) can be defined as the amount of force produced per second. Higher the value, the greater the athlete will be explosive.
Work for the explosion, the main setpoint data athletes during training bodybuilding is to move the load as quickly as possible. The only drawback to this methodology is the deceleration inherent in the movement before the end of the concentric phase. It is a reflex that allows joint protection when they arrive in full extension. For example, the bench press, researchers have shown that the acceleration of the bar when pushing (ie, concentric phase) was only 60% that of the movement. This implies that the deceleration of the bar operates on the remaining 40% of the trajectory. This implies a sub-optimal stimulus for agonist muscles involved.
There are several techniques to overcome this problem. The first is to project the load end of the movement. This is to run the bar bench or squat jump at the end, it thus requires adequate equipment to ensure the safety of athletes. The second technique is to use a variable resistor, Commes elastic bands, for example. The principle is that the resistance will increase throughout the concentric phase, which will allow a constant activation of agonist muscles. But what is the effect on the performance of this type of training?
To answer this question, in 2009, a team of American researchers from the University of Louisville, United States 12 weeks studied the effect of speed of execution and the variable resistance elastic bands squat (Fig . 2) on the development of strength and power in 48 male college athletes (baseball, track, football and basketball).
Before and after 12 weeks of protocol, athletes were subjected to two tests:
Measurement of the maximum force: Squat 1RM in
Measurement of the maximum power: 5 × CMJ
The 48 athletes were randomly assigned to 3 groups:
Group “Slow” heavy load – slow execution speed (0.2 – 0.4 m · s-1)
Group “Fast” Light Load – fast execution speed (0.6 – 0.8 m · s-1)
Group “Fast with elastic”: 50% of 1RM + bands – fast execution speed (0.6 – 0.8 m · s-1) (Fig. 3)
For the 3 groups, the training program for 12 weeks was the same: 2-3 workouts per week at 75-85% of 1RM (Squat, powercleans, deadlifts, lunges and deadlift with straight legs) and 1-2 workouts plyometric and sprint. Only the instructions for the squat were different among the 3 groups.
To control speed during each repetition squat, a displacement sensor was attached to the bar and a real-time feedback was given to the athlete to know if it realizes the movement at the right speed. For each group, selected squat load corresponded to the maximum load that each athlete can move at the speed required.
Statistical tests showed that only the difference in the maximum power from the group “Quick with elastic” and the group “Slow” was significant. No significant difference was observed between the 3 groups for maximal strength (Table 1). However, the researchers also determined the average percentages of progression and effects sizes.
The qualities of strength and speed can be improved by training with elastic resistance. Adding bands to squat and fast speed of execution led to a similar increase in maximal strength in comparison to the group using heavier loads, and a greater increase in the maximum power in comparison to the other two groups.
Squat in the human body becomes mechanically stronger when it reaches full extension, ie, when fully erect. With an elastic resistance, the athlete can produce more power over a longer period of the concentric phase. In addition, during the eccentric phase, the muscle is capable of storing elastic potential energy, and return in the form of kinetic energy, which will facilitate the pushing phase, and rightly, the tensile strength increases first part of the eccentric phase. It is possible that motor learning, athletes can learn to take advantage. We will discuss all these issues in the coming weeks in the second part of our article “Elastic bands: From Science to Practice”.
Training with elastic resistance appears to be beneficial to both the work force at working speed. It is also important to note that throughout the protocol, squat loads were chosen based on the execution speed of motion. At higher speeds, the addition of bands has a better gain maximum power and maximum strength.
In terms of training, bands are simple to implement and inexpensive. Additional resistance must be based on the athlete’s 1RM. It is also necessary to combine the two types of resistance (ie, inertial (cast iron) and variable (elastic)) so that the athlete can work at each phase of the movement. Indeed, the bottom of the movement, elastic bands provide less or no resistance, depending on how they have been attached. Finally, it is essential that training with elastic bands or explosive type, because the slow movement in the phase eccentric or concentric would be against-productive. The intention of the athlete should always be to maximize the execution speed, maintaining correct technique, of course.
It is also possible that training with elastic bands in optical performance is better suited to athletes confirmed. Indeed, novice bodybuilding athletes may not enjoy the benefit offered by the elastic resistance due to lack of strength and / or coordination of muscle and nerve.