Neuromuscular adaptations to sprint interval training and the effect of mammalian omega-3 fatty acid supplementation.
OBJECTIVE
Sprint interval training (SIT) stimulates rapid metabolic adaptations within skeletal muscle but the nature of neuromuscular adaptions is unknown. Omega-3 polyunsaturated fatty acids (N-3 PUFA) are suggested to enhance neuromuscular adaptations to exercise.


METHODS
We measured the neuromuscular adaptations to SIT (Study-1) and conducted a placebo-controlled randomized double blinded study to determine the effect of N-3 PUFA supplementation on neuromuscular adaptations to SIT (Study-2). In Study-1, seven active men (24.4 ± 2.6 years, VO2peak 43.8 ± 8.7 ml kg min-1) completed 2-weeks of SIT with pre- and post-training 10 km cycling time trials (TT). In Study-2, 30 active men (24.5 ± 4.2 years, VO2peak 41.0 ± 5.1 ml kg min-1) were randomly assigned to receive N-3 PUFA (2330 mg day-1) (n = 14) or olive oil (n = 16) during 2-weeks of SIT with pre- and post-training TTs. Four week post-training, a SIT session and TT were also performed. Change in neuromuscular function was assessed from resting twitches, quadriceps maximal voluntary contraction (MVC) force, and potentiated twitch force (Qtw).


RESULTS
Study-1 showed that SIT did not elicit significant neuromuscular adaptations. Study-2 showed that N-3 PUFA supplementation had no significant effect on neuromuscular adaptations. Training caused lower MVC force [mean ± SD; N-3 PUFA -9 ± 11%, placebo -9 ± 13% (p < 0.05 time)] and Qtwperipheral fatigue [N-3 PUFA -10 ± 19%, placebo -14 ± 13% (p < 0.05 time)]. TT time was lower after training in all groups [Study-1 -10%, Study-2 N-3 PUFA -8%, placebo -12% (p < 0.05 time)].


CONCLUSIONS
Two weeks of SIT improved TT performance in the absence of measurable neuromuscular adaptations. N-3 PUFA supplementation had no significant effect on SIT training adaptations.
Department of Nutritional Sciences, Faculty of Medicine, University of Toronto, 150 College St, Toronto, ON, M5S 3E2, Canada. Evan.lewis@utoronto.ca.
Evan J H
http://orcid.org/0000-0002-4353-2969
EJH
Lewis
Center for Sports Medicine, Swiss Olympic Medical Center, University Hospital of Geneva, Geneva, Switzerland.
Frédéric
F
Stucky
Faculty of Kinesiology and Physical Education, University of Toronto, 100 Devonshire Place, Toronto, ON, M5S 2C9, Canada.
Peter W
PW
Radonic
Department of Nutritional Sciences, Faculty of Medicine, University of Toronto, 150 College St, Toronto, ON, M5S 3E2, Canada.
Adam H
AH
Metherel
Department of Nutritional Sciences, Faculty of Medicine, University of Toronto, 150 College St, Toronto, ON, M5S 3E2, Canada.
Thomas M S
TMS
Wolever
Faculty of Kinesiology and Physical Education, University of Toronto, 100 Devonshire Place, Toronto, ON, M5S 2C9, Canada.|Physiology and Experimental Medicine, The Hospital for Sick Children, 555 University Ave, Toronto, ON, M5G 1X8, Canada.
Greg D
GD
Wells
D000222:Adaptation, Physiological; D000328:Adult; D019587:Dietary Supplements; D015525:Fatty Acids, Omega-3 / Q000008:administration & dosage / Q000009:adverse effects* / Q000494:pharmacology; D000072696:High-Intensity Interval Training; D006801:Humans; D008297:Male; D009119:Muscle Contraction; D018482:Muscle, Skeletal / Q000187:drug effects* / Q000502:physiology
D015525:Fatty Acids, Omega-3
Adaptations to training; Neuromuscular; Nutrition supplementation; Omega-3; Sprint interval training