View Full Version : increased p70(s6k) phosphorylation with protein/carbs post-workout in fasted state

12-06-2009, 04:27 PM
more complexities on whether or not to have protein/carbs prior to exercise.

Source Eur J Appl Physiol 2009 Nov 18.

http://www.unboundmedicine.com/medli..._fasted_state_ (http://www.unboundmedicine.com/medline/ebm/record/19921243/full_citation/Increased_p70_s6k__phosphorylation_during_intake_o f_a_protein_carbohydrate_drink_following_resistanc e_exercise_in_the_fasted_state_)
Increased p70s6k phosphorylation during intake of a protein–carbohydrate drink following resistance exercise in the fasted state

European Journal of Applied Physiology (http://www.springerlink.com/content/100513/?p=fca314b01c284be3a0eb86b722712298&pi=0)

Louise Deldicque2, Katrien De Bock1, Michael Maris1, Monique Ramaekers1, Henri Nielens2, Marc Francaux2 and Peter Hespel1 http://www.springerlink.com/images/contact.gif (http://www.springerlink.com/content/w8712615714k8150/#ContactOfAuthor7)

(1) Department of Biomedical Kinesiology, Research Center for Exercise and Health, FABER, K.U.Leuven, Tervuursevest 101, 3001 Leuven (Heverlee), Belgium(2) Research Group in Muscle and Exercise Physiology, Institute of Neurosciences, UCLouvain, Place Pierre de Coubertin 1, 1348 Louvain-la-Neuve, Belgium
Accepted: 29 October 2009 Published online: 18 November 2009
Communicated by Håkan Westerblad.

Abstract The present study aimed at comparing the responses of myogenic regulatory factors and signaling pathways involved in muscle protein synthesis after a resistance training session performed in either the fasted or fed state. According to a randomized crossover study design, six young male subjects participated in two experimental sessions separated by 3 weeks. In each session, they performed a standardized resistance training. After the sessions, they received during a 4-h recovery period 6 ml/kg b.w. h of a solution containing carbohydrates (50 g/l), protein hydrolysate (33 g/l), and leucine (16.6 g/l). On one occasion, the resistance exercise session was performed after the intake of a carbohydrate-rich breakfast (B), whereas in the other session they remained fasted (F). Needle biopsies from m. vastus lateralis were obtained before (Rest), and 1 h (+1h) and 4 h (+4h) after exercise. Myogenin, MRF4, and MyoD1 mRNA contents were determined by RT-PCR. Phosphorylation of PKB (protein kinase B), GSK3, p70s6k (p70 ribosomal S6 kinase), eIF2B, eEF2 (eukaryotic elongation factor 2), ERK1/2, and p38 was measured via western blotting. Compared with F, the pre-exercise phosphorylation states of PKB and p70s6k were higher in B, whereas those of eIF2B and eEF2 were lower. During recovery, the phosphorylation state of p70s6k was lower in B than in F (p = 0.02). There were no differences in basal mRNA contents between B and F. However, compared with F at +1h, MyoD1 and MRF4 mRNA contents were lower in B (p < 0.05). Our results indicate that prior fasting may stimulate the intramyocellular anabolic response to ingestion of a carbohydrate/protein/leucine mixture following a heavy resistance training session.

Keywords Skeletal muscle - Nutrition - Amino acids - Carbohydrates - p70s6k - MRF
L. Deldicque and K. De Bock contributed equally to this work.