Statistical analysis
REGRESSION
All data are reported as mean ± standard deviation (SD) and data analysis was performed using the statistical package JASP 0.16.2.0. (JASP team 2017) unless otherwise specified. All variables were assessed for parametric assumptions using the Shapiro-Wilk test of normality and Levene’s test for homogeneity of variance. Statistical significance was set at Standardized mean differences (SMD) were calculated, using Cohen’s SNPs associated with improved cardiorespiratory fitness identified by the ANOVA were summed by allele for each participant according to the following procedure. Homozygosity for alleles associated with improved exercise performance scored “2”, whilst heterozygosity scored “1” and homozygosity for no positive alleles scored “0”. The resultant allelic scores were summed and subjected to linear regression analysis against the percentage improvements in Cooper test scores. Allelic frequencies associated with improved Cooper run scores, were compared with expected European population frequencies (