SCIENCE

Furthermore, when athletes move loads at high speed, during the concentric phase there is a period of time in which the weight must be stopped (or decelerated) before generating resistance in the opposite direction: this phase is greatly reduced when using elastic resistance (Wallace et al. 2018) and consequently there is a better adaptation in reflex-type responses (i.e. rapid involuntary contractions in response to external stimuli) improving the electromechanical delay time (Smith et al. 2019).

The efficacy of this resistance for the improvement of strength and power is well documented in the literature (García-López et al. 2016; Soria-Gila et al. 2015; Aloui et al. 2019) with studies indicating even greater benefits than to constant resistance (Joy et al. 2016; Rivière et al. 2017; Rhea et al. 2009)

Elastic resistance can also be used to overload exercises with free weights (i.e. squats), especially in the last range of motion (Wallace et al. 2006). Consequently, LITE REVOLVE has been designed to make it easier to combine elastic resistance and barbells. The application of elastic resistance to free weights can avoid overloading at angles of contraction that are less advantageous at a mechanical level and by braking the inertia of the movement with a greater load it can increase stress during the entire range of motion. Thus, in exercises such as leg press, squat or bench press using elastic resistance, the early stages of the concentric phase may not be subjected to as much load as the latter, facilitating the eccentric-concentric transition in this type of exercise. During combined use of weights and elastic resistance, the literature recommends the use of an elastic resistance between 20-35% of the total load and the free weight between 65-80% of the maximum repetition (Stevenson et al. 2010). Hence the range of resistance offered by LITE REVOLVE allows the optimal execution of key exercises such as squats, deadlifts and thrusts in combination with barbells

Regarding the improvements obtained with the combined use of free weights and elastic resistances, there are studies indicating significant improvements in peak and average speed and power when moving loads compared to training with weights alone (Heelas et al. . 2019), as well as in the expression of the force-time slope (Stevenson et al. 2010) and in the velocity of eccentric conditions, which contribute to improving the efficiency of the stretching-shortening cycle (Wallace et al. 2018).