Drop-Set Training Elicits Differential Increases in Non-Uniform Hypertrophy of the Quadriceps in Leg Extension Exercise

Abstract

The study aimed to compare the effects of drop set resistance training (RT) versus traditional RT on markers of maximal muscle strength and regional hypertrophy of the quadriceps femoris. Sixteen recreationally active young men had one leg randomly assigned to the drop-set method (DS) and the other to training in a traditional manner (TRAD). Participants performed unilateral seated leg extensions using a periodized approach for eight weeks. Rectus femoris (RF) and vastus lateralis (VL) muscle thickness (MT), estimated one repetition maximum (RM) in the unilateral knee extension, and peak and average isokinetic knee extension torque at 60°/s angular velocity were measured pre- and post-study. Both conditions increased muscle thickness of the RF and VL from pre- to post-intervention. DS showed statistically greater increases in the RF at 30% and 50% of muscle length, whereas no MT differences were detected at 70% muscle length nor at any aspect of the VL. Both DS and TRAD increased estimated one RM from pre- to post-study (+34.6% versus +32.0%, respectively) with no between-condition differences noted. Both conditions showed similar increases in peak torque (DS: +21.7%; TRAD: +22.5%) and average torque (DS: +23.6%; TRAD: +22.5%) from pre- to post-study. Our findings indicate a potential benefit of the drop-set method for inducing non-uniform hypertrophic gains in the RF muscle pursuant to leg extension training. The strategy did not promote an advantage in improving hypertrophy of the VL, nor in strength-related measures, compared to traditional training.

Equal-Volume Strength Training With Different Training Frequencies Induces Similar Muscle Hypertrophy and Strength Improvement in Trained Participants

“…Previous studies have shown non-uniform hypertrophy in the quadriceps in response to resistance exercise ( Narici et al, 1996 ). Recently, drop sets were reported to induce greater gains in hypertrophy for the rectus femoris, but not vastus lateralis, compared with traditional resistance exercise training ( Varović et al, 2021 ). Consequently, we cannot exclude the possibility of regional differences in hypertrophy within or between muscles.…”

Muscular Adaptations in Drop Set vs. Traditional Training: A meta-analysis

“…A ration-ale for how this phenomenon may occur in DS is not readily apparent. Of note, both Varovic et al (32) and Enes et al ( 8) observed similar regional changes across the length of the vastus lateralis between conditions. Whether differential findings may be explained by differences in structural attachments between the rectus femoris and vastus lateralis (biarticular vs monoarticular, respectively) warrants further investigation.…”

“…Moreover, we did not detect appreciable evidence of heterogeneity between studies for the hypertrophy outcomes (I2 = 0%). Analysis of outliers identified the muscle thickness comparison of the rectus femoris at 30% muscle length in the study by Varovic et al (32) as being potentially influential; however, leave-one-out analysis showed its exclusion did not result in an appreciable difference in results.…”

“…Interestingly, Varovic et al(32) observed greater muscle thickness increases in the proximal-and mid-portions of the rectus femoris favoring DS vs TRAD. This was the only study to investigate hypertrophic changes at different sites along the length of the rectus femoris.…”

Connective Adaptive Resistance Exercise (CARE) Machines for Accentuated Eccentric and Eccentric-Only Exercise: Introduction to an Emerging Concept

“…As shown in Figs. 1 and 2 and elsewhere [ 33 ], CARE technology can automate the eccentric overload and drop setting, which are training strategies known to increase muscle size and strength [ 2 , 4 , 15 , 64 , 65 , 91 , 92 ]. Importantly, we do not propose that CARE machines necessary replace other types of resistance exercise equipment.…”