european college of sport science

Thursday, June 25th, 2009
Thursday, June 25 th , 2009
08:30 - 10:00
Invited symposia
IS-NU01 Nutrition and training adaptations (GSK Symposium)
THE EFFECT OF NUTRITION ON THE ADAPTATION TO TRAINING
MILLER, B.
COLORADO STATE UNIVERSITY
Exercise training initiates a series of signals that permit the remodeling of cells to be better equipped to deal with that stimulus in the
future. To optimally adapt to the signals put in motion, amino acid building blocks must be provided to construct the proteins of interest.
Post-exercise protein provision is well documented to increase protein synthesis after a bout of resistance training. Less explored is the
effect of post-exercise protein on endurance training adaptation. However, it is important to recognize that post-exercise protein intake
might be just as important for endurance-specific adaptation. In this talk, the importance of post-exercise protein ingestion will be discussed
in the context of strength and endurance training. Further, gaps in current research will be identified to optimize training adaptations.
DO ANTIOXIDANTS ENHANCE OR SUPPRESS TRAINING INDUCED ADAPTATIONS?
PHILP, A.
UNIVERSITY OF DUNDEE
Exercise involves a complex series of cellular events, which combine to mediate skeletal muscle adaptation. Muscle contraction evokes
signal transduction pathways regulated by calcium and ATP fluctuations as well as a stress response leading to systemic release of
hormones, and the muscle specific generation of reactive oxygen species and cytokines. As a general process, this response can be
termed exercise specific inflammation and recent research suggests that this transient inflammatory response is a key factor in exercise
adaptation (Petersen and Pedersen, 2005). If inflammation is prolonged however, such as during repetitive periods of intense training, or
sustained exhaustive exercise, deleterious effects develop within the working muscle suggesting that the range over which inflammation
is beneficial is small. Radicals and reactive oxygen species (ROS) are molecules that initiate damaging oxidation reactions within the cell
(Powers et al., 2004). ROS generation has been linked with exercise induced oxidative injury and muscle fatigue due to an imbalance
between oxidant production and the antioxidant capacity of the cell (Powers and Jackson, 2008). There are a number of enzymatic and
non-enzymatic defence systems, or antioxidants, in mammalian skeletal muscle which reduce free radicals and reactive oxygen species
production. Importantly, dietary antioxidants work in synergy with these endogenous antioxidants to offset ROS induced oxidative stress.
With this in mind, recreational and elite athletes supplement with antioxidant agents, in the belief that they will protect the athlete against
exercise-induced damage, local inflammation and enhance post exercise recovery. However, recent research suggests that dietary
antioxidants may in fact suppress ROS mediated signalling essential for exercise-induced adaptation (Powers and Jackson, 2008). Specifically
it appears that ROS generation is important for kinase activity of the AMP-dependent kinase (AMPK), the mitogen activated protein
kinases (p38 and p42/44) and their downstream targets NF-κB and the transcriptional co-activator PGC-1α (Gomez-Cabrera et al.,
2005; Irrcher et al., 2009). Therefore, whether antioxidants enhance or interfere with training adaptation and whether training regimes
and nutritional interventions should be adjusted to account for ROS action in response to exercise remains a controversial issue.
References
Petersen, AM and Pedersen, BK (2005) J. Appl. Physiol. 98(4): 1154-62.
Powers, SK et al., (2004) J. Sports Sciences. 22: 81-94.
Powers, SK and Jackson, MJ (2008) Physiol. Rev. 88: 1243-76
Gomez-Cabrera, M-C et al., (2005) J. Physiol. 567.1: 113-20
Irrcher, I et al., (2009) Am. J. Physiol. Cell Physiol. 296: C116-23
CARBOHYDRATE AND TRAINING ADAPTATIONS
JEUKENDRUP, A.
UNITED KINGDOM
Without abstract submission
OSLO/NORWAY, JUNE 24-27, 2009 109