Impact of Range of Motion During Ecologically Valid Resistance Training Protocols on Muscle Size, Subcutaneous Fat, and Strength

Abstract

The impact of using different resistance training (RT) kinematics, which therefore alters RT mechanics, and their subsequent effect on adaptations remain largely unreported. The aim of this study was to identify the differences to training at a longer (LR) compared with a shorter (SR) range of motion (ROM) and the time course of any changes during detraining. Recreationally active participants in LR (aged 19 ± 2.6 years; n = 8) and SR (aged 19 ± 3.4 years; n = 8) groups undertook 8 weeks of RT and 4 weeks of detraining. Muscle size, architecture, subcutaneous fat, and strength were measured at weeks 0, 8, 10, and 12 (repeated measures). A control group (aged 23 ± 2.4 years; n = 10) was also monitored during this period. Significant (p > 0.05) posttraining differences existed in strength (on average 4 ± 2 vs. 18 ± 2%), distal anatomical cross-sectional area (59 ± 15 vs. 16 ± 10%), fascicle length (23 ± 5 vs. 10 ± 2%), and subcutaneous fat (22 ± 8 vs. 5 ± 2%), with LR exhibiting greater adaptations than SR. Detraining resulted in significant (p > 0.05) deteriorations in all muscle parameters measured in both groups, with the SR group experiencing a more rapid relative loss of postexercise increases in strength than that experienced by the LR group (p > 0.05). Greater morphological and architectural RT adaptations in the LR (owing to higher mechanical stress) result in a more significant increase in strength compared with that of the SR. The practical implications for this body of work follow that LR should be observed in RT where increased muscle strength and size are the objective, because we demonstrate here that ROM should not be compromised for greater external loading.

Training-induced changes in architecture of human skeletal muscles: Current evidence and unresolved issues

“…This suggests that resistance training can induce an increase in fascicle length of human muscles in vivo. In the 2000s, some studies showed an increase in fascicle length following resistance or competitive training [43][44][45][46][47][48][49][50][51][52][53] . Overall, training-induced increases in fascicle length are accompanied by an increase in muscle size (muscle hypertrophy, which is defined as an increase in muscle fiber area, muscle thickness, anatomical crosssectional area or volume in this article), although four studies failed to find muscle hypertrophy 45,52,54,55) and two studies did not show the data on muscle size 56,57) .…”

“…McMahon et al 48) showed a substantial impact of range of motion of the knee joint (i.e., muscle length change) during training on VL fascicle length change. They demonstrated that fascicle length of VL increased after resistance training for 8 weeks regardless of range of motion, but the magnitude was greater at longer range of motion (0° to 90°) than at shorter range of motion (0° to 50°) conditions.…”

“…Some reports measured a fascicle length at several sites along VL 45,48,54,65,67,68) , and observed regional differences in the changes before and after intervention 45,54) . Noorkoiv et al 54) demonstrated that isometric training at a long muscle length position induced an increase in VL fascicle length in the distal region, whereas at a short muscle length position, an increment was shown in the middle region.…”

Pulling Exercises for Strength Training and Rehabilitation: Movements and Loading Conditions

“…Full range of motion has been associated with greater strength and muscle gains [42][43][44]. In this context, the LP and 45LP can be considered superior to the other exercises with regard to conditioning.…”

Six-Weeks training program to enhance wrestler relative strength

“…One of those, strength, is "Strength is the ability to apply force" [2] and the ability of muscles to cope with load or resistances. Meanwhile, strength level is influenced by some conditions: the length and size of muscles [13], the distance of load and fulcrum, the level of fatigue [14], the dominance of red and white muscle, muscle potential, the utilization of muscle, technique, and muscle contraction ability.…”