PhD Scientific Days 2023

Molecular Sciences II.

Sex-related adaptations to chronic in-season training

Text of the abstract

Little is known about sex-related differences in sports adaptations, most studies have been conducted in male athletes although female participation in sport has increased rapidly.
The purpose of this pilot study was to evaluate different and common traits between male and female adaptations to chronic in-season training comparing redox, hormonal, proteomic, metabolic and lipid profiles of plasma samples of professional basketball players, female and male, and relative sedentary as control.
Player groups showed both an increased antioxidant capacity and lactate level compared to controls while a peculiar metabolic (in particular, amino acids and urea), hormonal, and lipidic profile were highlighted. An increase of urea levels with a contemporary low level of L-ornithine were observed in female athletes and might be interpreted as early signs of fatigue and overreaching. A considerable amount of ammonia is released from aminoacid catabolism that occurs in muscle and is converted into urea in liver. Ornithine has an antifatigue effect promoting the excretion of ammonia and increasing the efficiency of energy consumption.
Plasma proteomic analysis showed, among proteins with a reduction in expression level in female athletes in comparison to male, RNA-binding protein 15 (RBP-15), a protein related to skeletal muscle adaptation, and acyl-coenzyme A oxidase peroxisomal (ACOX1).
In female athletes, we found an increase in several fatty acids (FAs), physical activity could increase lipolysis of adipose tissue triglycerides but their accumulation on plasma might be related with the reduced level of ACOX1 which plays an important role in physiological retroconversion of polyunsaturated fatty acids.
We highlighted a sex-dependent changes in plasma adiponectin levels since in male athletes increases, conversely, we do not find this variations in female despite follow the same training program. Adiponectin is a miokine with anti-inflammatory properties that acts on skeletal muscle modifying glucose and fatty acid metabolism.
In conclusion, female and male have distinct muscle properties such as a reduced size, number and dimeter of fibers that mainly explains the differences observed in our study. A personalized training is then mandatory to reduce inflammation and skeletal muscle catabolic stimuli leading to a reduction in muscle mass and function up to overtraining.
This research was funded by Ricerca di Ateneo ex 60% 2020 from the University of Florence.