Hypertrophy of Lumbopelvic Muscles in Inactive Women: A 36-Week Pilates Study.
BACKGROUND
The use of Pilates in various fields of sport sciences and rehabilitation is increasing; however, little is known about the muscle adaptations induced by this training method.


HYPOTHESIS
A standardized Pilates training program for beginners (9 months; 2 sessions of 55 minutes per week) will increase the muscle volume and reduce potential side-to-side asymmetries of the quadratus lumborum, iliopsoas, piriformis, and gluteus muscles (gluteus maximus, medius, and minimus).


STUDY DESIGN
Controlled laboratory study.


LEVEL OF EVIDENCE
Level 3.


METHOD
A total of 12 inactive, healthy women (35.7 ± 5.4 years) without previous experience in Pilates were randomly selected to participate in a supervised Pilates program (36 weeks, twice weekly). Muscle volume (cm3) was determined using magnetic resonance imaging at the beginning and end of the intervention program. Side-to-side asymmetry was calculated as [(left - right volume) × 100/right volume].


RESULTS
Small, nonsignificant (P > 0.05) differences in the volume of the quadratus lumborum, iliopsoas, piriformis, and gluteus muscles were observed between pre- and post-Pilates program timepoints. Before and after Pilates, side-to-side asymmetry was less than 6% and nonsignificant in all muscles analyzed.


CONCLUSION
Modern Pilates performed twice weekly for 9 months did not elicit substantial changes in the volume and degree of asymmetry of the selected lumbopelvic muscles in inactive women.


CLINICAL RELEVANCE
The benefits of Pilates in rehabilitation or training are likely elicited by neuromuscular rather than morphological adaptations. Pilates has no significant impact on muscle volume and does not alter side-to-side ratios in muscle volume (degree of asymmetry) of the lumbopelvic muscles.
['Dorado|Cecilia|C|', 'López-Gordillo|Ana|A|', 'Serrano-Sánchez|José A|JA|', 'Calbet|José A L|JAL|', 'Sanchis-Moysi|Joaquín|J|']
D000009:Abdominal Muscles D000222:Adaptation, Physiological D000328:Adult D064131:Back Muscles D026241:Exercise Movement Techniques D005260:Female D006801:Humans D008279:Magnetic Resonance Imaging D010388:Pelvis D064797:Physical Conditioning, Human
hypertrophy muscle magnetic resonance imaging Pilates-based exercises