«BOOK OF ABSTRACTS Edited by: Loland, S., Bø, K., Fasting, K., Hallén, J., Ommundsen, Y., Roberts, G., Tsolakidis, E. Hosted by: The Norwegian ...»
16:15 - 17:30 Plenary sessions PS-PL01 Born to move? Perspectives from evolutionary biology and the social sciences
HUMAN ADAPTABILITY TO MOVE: INTERNAL AND EXTERNAL RESOURCES.MINETTI, A.E.
UNIVERSITY OF MILANDifferently from other species that, apart from long migrating animals, are optimized in their body design to move within a given habitat, humans have always struggled to adapt to all sorts of environments, ranging from level to steep terrain, at all latitudes, in a variety of climates, even on different planets. Also, within the same environment and penalized by the bipedal, erect posture, man has always tried to push the muscle powered locomotor performance to the limit, by inventing tools capable to better exploit the same engine and machinery. Achieving a higher speed at a manageable metabolic cost and expenditure promoted the development of paved roads, optimally steep paths, prepared snow surfaces, calm (sometimes frozen) water ways, and a variety of locomotion aids like carts and bicycles, skis/skates and sleds, canoes and rowing boats, up to human powered submarines and aircrafts.
By reviewing the history of an often fortuitous ‘symbiosis’ of physiology and engineering in the different forms of locomotion (see References below), some of which dates back to prehistory, the invariant characteristics of the propeller (muscle) emerge and the most frequent winner, i.e. the pedalling paradigm, is the modality of choice in many forms of modern propulsion.
REFERENCESMinetti A. E. Optimum gradient of mountain paths. J. Appl. Physiol. 79(5): 1698-1703, 1995.
Minetti A. E. Walking on other planets. Nature 409: 467-469, 2001.
Minetti A. E., J. Pinkerton and P. Zamparo. From bipedalism to bicyclism: evolution in bioenergetics and biomechanics of historic bicycles.
Proc. R. Soc. B 268: 1351-1360, 2001.
Zamparo P., D. R. Pendergast, A. Termin and A. E. Minetti. How fins affect the economy and efficiency of human swimming. J. exp. Biol.
205: 2665-2676, 2002.
Minetti A. E. and L. P. Ardigò. Halteres used in ancient Olympic long jump. Nature 420: 14-15, 2002.
Minetti A. E. Passive tools for enhancing muscle-driven motion and locomotion. J. Exp. Biol. 207: 1265-1272, 2004.
Ardigò L. P., V. L. Goosey-Tolfrey and A. E. Minetti. Biomechanics and energetics of basketball wheelchairs evolution. Int. J. Sports Med., 26: 389-397, 2005.
Formenti F., Ardigó L. P. and A. E. Minetti. Human locomotion on snow: determinants of economy and speed of skiing across the ages.
Proc. R. Soc. B, 272(1572): 1561-1569, 2005.
Minetti A. E., Formenti F., and Ardigò L. P. Himalayan porter’s specialization: metabolic power, economy, efficiency and skill. Proc. R. Soc.
B, 273: 2791- 2797, 2006.
Formenti F. and A. E. Minetti. Human locomotion on ice: the evolution of ice skating energetics through history. J. Exp. Biol., 210: 1825Formenti F. and A. E. Minetti. The first humans travelling on ice: an energy saving strategy? Biol. J. Linnean Soc. 93: 1-7, 2008
BORN TO MOVE? PERSPECTIVES FROM THE SOCIAL SCIENCES.FASTING, K.
NORWEGIAN UNIVERSITY OF SPORTHuman beings not only are born to move but also have the right to move. UNESCO’S International Charter of Physical Education and Sport, (Article 1) states that: “The practice of physical education and sport is a fundamental right for all”. In spite of the fact that people are born to move and have the right to do so, it often doesn’t seem to be put into practice. As a result people’s participation in leisure time physical activities and sport varies between and within cultures particularly in relation to gender, but also in relation to religion, sexuality, social class, disability, race, ethnicity and immigrant status. A further perspective from the social sciences on this issue will therefore be to discuss and explain this variation. Due to the time available the focus of the presentation will mainly be on the relationship between gender and sport in a social constructionist perspective, with a focus on ‘doing gender’. Gender refers to cultural meanings and connections associated with one’s biological sex, and what is appropriate behaviour for women and men (Lorber 1994). Historically there has been a strong relationship between sport and hegemonic “masculinity”, while the opposite has been true for sport and “femininity”. The societal gender stereotypes have therefore functioned as barriers for many girls and women. This has led to gender based discrimination in sport (United Nations 2007). Many of these barriers have been overcome over the last few years since both sport and the concepts of “masculinity” and “femininity” are constantly changing. The presentation will close with some examples of how people have met the challenges they have faced through sport, how they have overcome discrimination, and how involvement in sport has challenged the gender stereotypes and discrimination, and how involvement in sport can be a vehicle for gender equality and empowerment.
Lorber, Judith (1994), Paradoxes of Gender.Yale University Press, London United Nations (2007), Women, gender, equality and sport.
Thursday, June 25th, 2009 08:30 - 10:00 Invited symposia IS-NU01 Nutrition and training adaptations (GSK Symposium)
THE EFFECT OF NUTRITION ON THE ADAPTATION TO TRAININGMILLER, B.
COLORADO STATE UNIVERSITYExercise 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 DUNDEEExercise 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 ADAPTATIONSJEUKENDRUP, A.
08:30 - 10:00 Oral presentations OP-HF06 Health and Fitness 6
THE DECLINE OF VO2MAX FROM 20 TO 84, THE HEALTH SURVEY OF NORD-TRØNDELAGASPENES, S., ULRIK, W.
NORWEGIAN UNIVERSITY OF SCIENCE AND TECHNOLOGYIntroduction: Maximal oxygen uptake (VO2max) declines with increasing age in both men and women. In cross-sectional studies the decrease has been found to range between 0.40-0.50 mL∙kg-1∙min-1∙year-1 in men and 0.20-0.35 mL∙kg-1∙min-1∙year-1 in women (Jackson et al., 1995). However, most studies use the term VO2peak thereby indicating a submaximal measurement of oxygen uptake, or estimate aerobic capacity from an indirect measurement. We aim to investigate the decline of true VO2max in a large population from measurements on treadmill.
Methods: As a part of the third part of the Health Survey of Nord-Trøndelag (HUNT3), 5641 healthy individuals between 20 and 93 was recruited for testing maximal oxygen uptake. From these, 4060 individuals (2017 women and 2043 men, age 20 to 84) tested their maximal oxygen uptake and during this test reached a respiratory quotient of 1.05 or more. The test was performed with the MetaMax2 and it was brought out with an individualized protocol.
Normality was investigated by Q-Q-plot and histogram with normal distribution curve, and the regression of the relationship between VO2max as dependent variable and age as the independent variable.
Results: VO2max declined from 54.3 ± 8.4 mL∙kg-1∙min-1 in the agegroup 20-29 years to 35.5 ± 6.8 mL∙kgmin-1 in the agegroup above 70 years in men and from 43.0 ± 7.6 mL∙kg-1∙min-1 in the agegroup 20-29 years to 27.9 ± 5.1 mL∙kg-1∙min-1 in the agegroup above 70 years in women. The slope of regression was -0.379 with an R squared of 0.308 in men, and the slope was -0.309 with an R squared of 0.288 in women. The regression was highly significant (p 0.001) for both men and women. The decline in percent per decade is 9.6, 4.3, 10.1, 8.3 and 11.2 in men and 7.0, 4.8, 11.1, 9.2 and 12.4 in women.
Discussion: The decline of 0.379 mL∙kg-1∙min-1∙year-1 in men was slightly lower than earlier reports while the decline of 0.309 mL∙kg-1∙min-1∙year-1 in women was similar to earlier findings. The highly significant p-value of the regression underlines the strength of the relationship while the low R squared indicate that age explains only 30.8% and 28.8% of the decline in men and women, respectively.
The decline is not a steady one, comparing percents decline between decades suggest a decline of shifting steepness. A likely explanation for these shifts is different patterns of physical activity. Unfortunately this was not studied this time in our study. We find that in a healthy Norwegian population, the natural decline from age 20 will be approximately 0.7% per year in both men and women, but the steepness of decline is shifting between the decades and the relationship between VO2max and physical activity should be investigated further in our population.
References Jackson AS, Wier LT, Ayers GW, Beard EF, Stuteville JE, Blair SN (1995) Med Sci Sports Exerc, 28(7), 884-891.