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DOES FULL RANGE OF MOTION MATTER?

Dr. Paul C. Henning PhD CSCS

Time and time again I have seen people in the gym sacrifice range of motion (ROM) in order to lift heavier weights! Whether this is due to ignorance of how to perform the exercise correctly or ego, this practice is quite prevalent in gyms around the country.

The manipulation of training stimulus: exercise selection and order, mode of contraction, intensity, recovery, and volume determine the degree of hypertrophy attained [1]. There are numerous studies on these variables in the literature, but one potential important aspect of training kinematics (i.e., ROM) that may not have previously been considered is the effects of ROM on muscle mechanics during RT, and the subsequent adaptations as a result.


The evidence…

Therefore, a recent study aimed to examine the effects of resistance exercise training and a detraining period over a larger ROM (LR) and hence longer average muscle length (0-90° knee flexion-LR) vs. a smaller ROM (SR) and hence shorter average muscle length (0-50° knee flexion-SR) on morphological, architectural, and functional changes in the vastus lateralis (VL) muscle in the quadriceps [2]. This study had three groups: SR, LR and a control group. Resistance training was performed 3 times per week by both the SR and LR training groups for 8 weeks using a combination of free, machine and body weights. Exercises were performed at 80% of 1RM (repetition maximum). The 8 weeks of training was followed by a 4 week detraining period. Participants in this study took part in recreational activities such as team sports and had either never taken part in lower limb RT or have not over the last 12 months.


Main findings…

Significant adaptations occurred in both SR and LR training groups across all the muscle measurements. What is really interesting was that there was a significant main effect of training where strength, vastus lateralis muscle length, and vastus lateralis cross-sectional area increased, whereas midthigh subcutaneous fat decreased to a greater extent after training at a larger ROM compared with a shorter ROM! .

In addition, the detraining period demonstrated that both groups resulted in significant losses in all measures. This study showed that although initial gains may be lost at a greater rate in LR; training with a relatively greater ROM may still present an advantage for the longer term. This was evident in the strength data where the LR group was significantly stronger until the end of the detaining period, whereas the SR group was not compared with pre-training levels.


Summary

After 8 weeks of RT and 4 weeks of detraining over different ROM, morphological differences were greater and strength was enhanced to a greater extent after training at a larger rather than a narrow ROM. This research demonstrates that RT protocols enforcing a wider ROM enhance the muscle characteristics that influence force and power production to a greater extent than protocols where ROM is not as extensive. In addition, adherence to a greater ROM also provides better long-term training adaptations, for example, after prolonged immobilization or bed rest caused by illness and injury or during a tapering period for a major competition.


References:

1. Ratamess, N., Alvar, BA, Evetoch, TK, Housh, TJ, Kibler, WB, Kraemer, WJ, and Triplett, NT., Progression models in resistance training for healthy adults. Med Sci Sports Exerc, 2009. 41: p. 687-708.

2. McMahon, G.E., et al., Impact of range of motion during ecologically valid resistance training protocols on muscle size, subcutaneous fat, and strength. J Strength Cond Res, 2014. 28(1): p. 245-55.


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