Circadian clock gene variants may affect circadian fluctuations of anaerobic performance Gene variants and performance

Abstract

Aim: Circadian rhythm (CR) may be followed by almost all biochemical and physiological processes that occur in the human body. Physical activities involving anaerobic fitness have displayed a dear CR. The aim of this study was to investigate genotype and allele frequencies of (PER3 VNTR, PER2 VNTR and TIM1) gene polymorphisms in athletes and control groups and the second aim was to examine the anaerobic performance according to the genotype distribution of mate footballers. Material and Methods: The study included 20 male footballers and 30 voluntary male controls. To examine anaerobic performance, the footballers performed three randomized 30-s Wingate anaerobic power tests (WAnT) in the morning, at noon and in the evening with minimal one-week recovery time between each testing day. Genomic DNA was isolated from the blood samples. Polymerase chain reaction-based and restriction fragment length polymorphism (PCR-RFLP) analysis was used to identify gene variants from DNA material. Also, the differences between the basic performance characteristics of the athletes and the genotype distribution of these variants were investigated according to the daytime. Results: The allele and genotype distribution of these variants was not significantly different between male footballers and the control group. Peak power and average power in the morning increased in athletes carrying TIM1 G/G variant (p<0.001) than in athletes carrying G/C and CC variant Also, the athletes carrying the TIM1 G/G variant had a higher minimum power In the morning and evening (p<0.001) than athletes carrying G/C and CC variant. Discussion: This is the first study that evaluates variants of circadian rhythm genes and the anaerobic performance of elite Turkish athletes. Our results suggested that the TIM1 gene variant may affect circadian fluctuations in anaerobic performance. People who carry the GIG genotype from the TIM1 gene have a higher anaerobic power. To understand ethnic and environmental differences, further studies are needed in this field.