Intra-individual differences in the effect of endurance versus resistance training on vascular function: A cross-over study

Scand J Med Sci Sports. 2021 Aug;31(8):1683-1692. doi: 10.1111/sms.13975. Epub 2021 May 12.


We used a within-subject, cross-over design study to compare the impact of 4-weeks' resistance (RT) versus endurance (END) training on vascular function. We subsequently explored the association of intra-individual effects of RT versus END on vascular function with a single nucleotide polymorphism (SNP) of the NOS3 gene. Thirty-five healthy males (21 ± 2 years old) were genotyped for the NOS3 rs2070744 SNP and completed both training modalities. Participants completed 12 sessions over a 4-week period, either RT (leg-extension) or END (cycling) training in a randomized, balanced cross-over design with a 3-week washout period. Participants performed peak oxygen uptake (peak VO2 ) and leg-extension single-repetition maximum (1-RM) testing, and vascular function assessment using flow-mediated dilation (FMD) on 3 separated days pre/post-training. Peak VO2 increased after END (p < 0.001), while 1-RM increased after RT (p < 0.001). FMD improved after 4-weeks' training (time effect: p = 0.006), with no difference between exercise modalities (interaction effect: p = 0.92). No relation was found between individual changes (delta, pre-post) in FMD to both types of training (R2 = 0.06, p = 0.14). Intra-individual changes in FMD following END and RT were associated with the NOS3 SNP, with TT homozygotes significantly favoring only END (p = 0.016) and TC/CC tending to favor RT only (p = 0.056). Although both training modes improved vascular function, significant intra-individual variation in the adaptation of FMD was found. The association with NOS3 genotype suggests a genetic predisposition to FMD adapting to a specific mode of chronic exercise. This study therefore provides novel evidence for personalized exercise training to optimize vascular health.

Keywords: aerobic training; endothelial function; genetics; response to training; strength training; trainability.

Publication types

  • Comparative Study

MeSH terms

  • Adaptation, Physiological / genetics*
  • Brachial Artery / physiology*
  • Cross-Over Studies
  • Endurance Training / methods*
  • Exercise Test
  • Genotype
  • Humans
  • Male
  • Nitric Oxide Synthase Type III / genetics*
  • Resistance Training / methods*
  • Vasodilation / genetics*
  • Vasodilation / physiology*
  • Young Adult


  • NOS3 protein, human
  • Nitric Oxide Synthase Type III