Proceedings of The Physiological Society

The Biomedical Basis of Elite Performance 2016 (London, UK) (2016) Proc Physiol Soc 35, PC48

Poster Communications

The effects of selective breeding and endurance training on the maximum aerobic exercise metabolism in bank voles

M. Dzialo1, E. T. Sadowska1, P. Koteja1

1. Institute of Environmental Sciences, Jagiellonian University, Kraków, Lesser Poland, Poland.

Problem: It is known that nature (genetic factors) and nurture (environmental factors) influence physiological performance traits, such as the aerobic capacity. An intriguing question is whether and to what extent a genetically determined superior performance is mediated by an increased propensity to the effects of training. Purpose: The aim of this study was to check whether long-term artificial selection (20 generations) for increased maximum rate of aerobic metabolism achieved during voluntary exercise (swimming; VO2swim), which resulted in about 50% increase of VO2swim, improved also the effect of training of aerobic performance traits in bank voles (Myodes glareolus). Methods: Males from four selected (A) and four unselected, control (C) lines (32 individuals from each type of lines) were randomly assigned to two groups (at the age of 51-56 days). In one group the animals were subject to interval training three times a week for 8-weeks. Each training session consisted of ten 2.0 min cycles, and each cycle comprised three phases: 0.5 min of "active rest" (running at 1km/hour), 0.5 min of speeding up, and 1 min running at sub-maximal speed (2.5-4.1 km/h; chosen individually, based on preliminary trials). Animals from the second group were sedentary, but were accustomed to the treadmill. At the beginning and the end of experiment measurements of the maximal rate of forced-running exercise metabolism (VO2max) and endurance running distance (ERD) were performed. All the protocols were approved by the Local Ethical Committee in Kraków (decision 66/2012). Results: Analysis of covariance showed that training had no effect on body mass (F1,6=1.18, P=0.32), but at the end of experiment voles from the A lines had a higher body mass than those from C lines (adjusted least-square means (LSM)±SE: A: 26.4±0.4 g, C: 22.7±0.7 g; F1,6=8.05, P=0.03). Selection resulted in increased post-training VO2max (mass-adjusted LSM±SE, A-lines: 5.1±0.1 ml O2/min; C-lines: 4.1±0.1 ml O2/min, F1,6=37.13, P<0.01) and a higher ERD (A-lines: 1824±180 m, C-lines: 1206±180 m, F1,6=7.71, P=0.03). However, training had increased only endurance (trained: 1938±176 m, sedentary: 1163±170 m; F1,6=18.40, P<0.01), without changing level of VO2max in either type of lines (F1,6=0.30, P=0.61).The selection × training interaction was not significant for any of the traits. Conclusion: This experiment showed that selection (nature) was effective in increasing the aerobic performance traits, but did not increase effect of training (nurture). Interestingly, the results revealed that ERD has been improved despite the fact that VO2max remained unchanged. This suggest that endurance running in bank vole may not be limited by VO2max.

Where applicable, experiments conform with Society ethical requirements