|You want to get rid of those tiny weights and squat big time? Maybe you should watch your squatting velocity... and no, I am not talking about slowing down - rather about keeping your rep speed.|
Previous studies have shown that the degree of neuromuscular fatigue induced by RT protocols can be monitored by assessing the repetition velocity loss within a set (Sanchez-Medina. 2011).
In the study at hand, the scientists did thus use a novel, velocity-based approach to resistance training programming, in which the fixed number of repetitions you have to perform with a given load is replaced by two hitherto largely ignored, closely related variables:
- the repetition’s mean velocity (how far are you squatting down and getting back up), which is intrinsically related to relative loading magnitude, and
- the velocity loss to be allowed, expressed as a percent loss in mean velocity from the fastest (usually first) repetition of each exercise set.
|Table 1: Descriptive characteristics of the velocity-based squat training program performed by both experimental groups | Data are mean SD. Only one exercise (full squat) was used in training (Pareja-Blanco. 2016).|
"The two groups trained at the same relative loading magnitude (per centage of one-repetition maximum, %1RM) in each session but differed in the maximum percent velocity loss reached in each exercise set (20% vs 40%). As soon as the corresponding target velocity loss limit was exceeded, the set was terminated. Sessions were performed in a research laboratory under the direct supervision of the investigators, at the same time of day ( 1 h) for each subject and under controlled environmental conditions (20 °C and 60% humidity). Subjects were required not to engage in any other type of strenuous physical activity, exercise training, or sports competition for the duration of the present investigation. Both VL20 and VL40 groups were assessed on two occasions: 48 h before (Pre) and 72 h after (Post) the 8-week training intervention. Training compliance was 100% of all sessions for the subjects that completed the intervention" (Pareja-Blanco. 2016).Pre- and post-training assessments included: magnetic resonance imaging, vastus lateralis biopsies for muscle cross-sectional area (CSA) and fiber type analyses, one-repetition maximum strength and full load-velocity squat profile, countermovement jump (CMJ), and 20-m sprint running - the analysis yielded the following results:
- The VL20 group trained at a significantly faster mean velocity than those from VL40 (0.69 +/- 0.02 vs 0.58 +/- 0.03 m/s, respectively; P < 0.001), but did sign. less reps [VL40 performed more repetitions (P < 0.001) than VL20 (310.5 +/- 42.0 vs 185.9 +/- 22.2)].
- The mean fastest repetition during each session (that which indicates the relative magnitude of the load being lifted) did not differ between groups (0.75 +/- 0.03 vs 0.76 +/- 0.01 m/s, for VL40 and VL20, respectively) and initial repetition velocities matched the expected target velocities for every training session.
- The VL40 group reached muscle failure during 27.0 +/- 4.2 sets (56.3% of total training sets), the VL20 group did not reach failure at all.
- Total work was significantly greater for VL40 compared to VL20 (200.6 +/- 47.1 vs 127.5 +/- 15.2 kJ, P < 0.001).
Now based on the often-heard and actually scientifically backed assumption that increases in total volume and training to failure are both conducive to strength gains, we should expect that the VL40 group saw greater increases in muscle size and 1RM strength. This was yet not the case.
Instead, (1) VL20 resulted in similar squat strength gains as VL40, (2) VL20 resulted in greater improvements in CMJ (9.5% vs 3.5%, P < 0.05), and (3) both groups saw identical increases in mean fiber CSA.
And the above occured in spite of the fact that the VL20 performed 40% fewer repetitions and never reached failure. Can't be? Well, you're right, there's more to the story:"Although both groups increased mean fiber CSA and whole quadriceps muscle volume, VL40 training elicited a greater hypertrophy of vastus lateralis and intermedius than VL20" (Pareja-Blanco. 2016).
|Figure 2: Changes in muscle volume for: (a) Whole quadriceps femoris; (b) rectus femoris (RF); (c) vastus medialis (VM); and (d) vastus lateralis plus vastus intermedius (VL+VI | Pareja-Blanco. 2016).|
- Pareja‐Blanco, F., et al. "Effects of velocity loss during resistance training on athletic performance, strength gains and muscle adaptations." Scandinavian Journal of Medicine & Science in Sports (2016).
- Sanchez-Medina, Luis, and Juan José González-Badillo. "Velocity loss as an indicator of neuromuscular fatigue during resistance training." Med Sci Sports Exerc 43.9 (2011): 1725-1734.