It’s no secret that strength athletes are elated when they hit new personal bests while simultaneously increasing muscle mass and strength. For the better part of the last decade, it has been known that in order to optimize muscle growth and strength improvements, strength exercises must be performed to the point at which no further repetitions can be completed—otherwise known as task failure. But, how do we accurately determine whether or not we’ve actually pushed our bodies to their physical limits? Gym goers commonly experience task failure based on perceived exertion. However, our brain often gives our body a false warning that our muscles are fatigued during exercise.
What if I told you that researchers from around the globe have collaborated to identify a new, more reliable warning system that informs you when you’re actually approaching your maximum number of repetitions to failure?
Dr. Paulo Gentil and colleagues have verified that movement velocity, or the speed with which a repetition is performed, is a simple and reliable metric to identify muscle fatigue and impending muscle failure during weight lifting exercises. Like a pianist uses a metronome to keep pace while practicing a melody, a weightlifter can use a metronome to pace their repetitions during training sessions. In a new study published in Applied Physiology, Nutrition, and Metabolism, participants performed two sets of metronome-paced repetitions of bench press exercise. The participants performed these repetitions until task failure, lifting a weight that allowed them to perform ~14 repetitions to failure or lifting a heavier weight that allowed them to perform ~8 repetitions to failure. When performing the lower repetition with heavier weight exercise, the participants demonstrated a significant decline in the velocity with which they performed the second last repetition; this effect was dramatically emphasized in the final repetition prior to failure. This means that we can use the slowing of timed, rhythmic repetitions as a successful predictor of muscular fatigue and impending muscle failure. However, this phenomenon was not observed with the higher repetition, lower weight exercise and may only apply to heavy load exercise.
This warning system has numerous implications within the fitness industry. Dr. Gentil suggests that this method can “make it easier for people to get the desired results in their training” and provides a safe approach to maximizing strength and muscle gains for individuals lifting weights without a spotter. Performing exercises to failure is often deemed dangerous and is not recommended without supervision from a personal trainer or otherwise qualified individual. This method can also help personal trainers push their clients past the mental barrier of discomfort to keep working towards achieving task failure.
We live in an era enthralled in fancy fitness gadgetry to help maximize human performance; fitness trackers are predicted to amount to US$2.6 billion by the end of 2018. Dr. Gentil is paving a path towards affordable fitness measurements that ensure optimal performance outcomes and the safety of gym goers. Next time you head to the gym, make sure to download a metronome app on your cellphone or be cognizant of the clock rhythmically ticking on the wall, as this may be your cost-effective ticket to new personal bests, increased muscle mass, and improved strength.
Read the full paper —Using velocity loss for monitoring resistance training effort in a real-world setting in Applied Physiology, Nutrition, and Metabolism.
