Many of those starting out with strength training at the gym make the mistake of performing their reps too quickly, believing that speed or the number of plates on the bar are the true indicators of success. However, trainer Lucía Aguado warns that this practice is counterproductive for those seeking real results.
“I’m afraid to tell you, but training isn’t about moving weight“, stresses the expert in a video on social media. And she believes speed is often the symptom of a common mistake that hinders muscle growth and increases the risk of injury: the use of inertia instead of controlled muscular strength to lift weights.
The four phases of a weight-lifting movement
To understand how to lift weight correctly, the trainer urges us first to understand the ‘difference between training and going to the gym’. And whereas going to the gym may simply involve completing repetitions with little precision or control, true training requires mastering the four phases of each exercise.
Thus, as the expert explains, “every movement you make in the gym has four phases: eccentric, concentric and the transition phases between them“. The problem arises when you work without the necessary control of these stages, especially when attempting to handle excessive loads carelessly.
The mistake of exploiting inertia
According to Aguado, when performing ballistic or rebound movements, “you are taking advantage of inertia”. Based on scientific principles, she notes that “according to Newton’s third law, a weight in motion tends to continue moving unless something stops it”. This means that if a lifter allows the weight to fall under control, “that weight already has accumulated velocity and that momentum makes the ascent easier“. In essence, “if you bounce it, you’re not lifting the weight”, you’re letting physics do the work for you.
Esta técnica errónea basada en la velocidad afecta al desarrollo físico. “Para crecer, el músculo necesita tensión mecánica”, recuerda la entrenadora, que habla de los efectos negativos de trabajar con esta inercia: se termina “reduciendo el tiempo bajo tensión”, se acaba “disminuyendo el esfuerzo muscular en el inicio de la fase concéntrica” y, lo más peligroso, se termina “trasladando la carga del músculo a los tendones”. En definitiva, “todo esto ayuda a que tus músculos trabajen menos”.
How to avoid it?
To correct this misguided approach and improve the quality of the strength routine, the trainer suggests “voluntarily slowing down in the eccentric phase and stopping in the transition phase before starting the concentric phase”, rather than allowing rebound. By incorporating this strategic pause into the weighted movement, “you will remove the accumulated inertia, stored elastic energy and the stretch reflex that promotes momentum”. The benefit, Aguado notes, is immediate in terms of effectiveness: “you take the work away from the tendons and give it back to your muscle”.
That said, bear in mind that implementing this methodology may give your ego a little sting, as you are likely not able to handle the same loads as before. Nevertheless, the trainer urges you to try it. “Give it a go at your next session and you’ll have to reduce the weight you lift, but keep at it for weeks and tell me,” she says in the video. And for the expert, the key to long-term success is clear. “Train with awareness and not with inertia,” she says, to achieve a genuine improvement in the quality of your workouts.
