RESUMEN
Low Energy Availability (LEA) arises from the inability to cover energy needs and requirements of training or normal physiological functions. This value differs from the energy balance, which takes into account the total daily energy intake compared to all the energy expended, regardless of the amount of fat-free mass. Insufficient energy consumption affects recovery, adaptation processes, increases the risk of injury or illness, so all of this can negatively affect performance. This mini-review is written on research articles in Pubmed database related to LEA in endurance-trained men and its impact on performance and testosterone. This article also clarifies the prevalence of LEA in male endurance athletes and its correlation to Relative Energy Deficiency in Sports (RED-S). LEA occurs in male endurance athletes and correlates with decreased testosterone levels, decreased bone density and also Resting Metabolic Rate. In endurance-trained men, there is great potential for the negative consequences of low energy availability. It can also be said that there are possibilities for primary screening, so we recommend regular check-ups of blood markers, body structure and keeping not only training but also dietary records, which can increase awareness of an adequate energy balance.
RESUMEN
A well-synchronized circadian system is a manifestation of an individual's health. A gradual weakening of the circadian timing function characterizes aging. Regular exercise has been suggested as a modality to improve many detrimental changes associated with aging. Therefore, we aim to examine the benefits and risks of lifelong endurance exercise on age-dependent changes in the circadian time-keeping function, the performance of the muscular system and health status. The study protocol has a comparative cross-sectional design, including groups of senior (65 to 75 years old, n=16) and young (20-30 years old, n=16) endurance runners and triathletes. Age-matched groups of young and elderly sedentary men are included as controls. The circadian function is evaluated mainly by measurement of urinary 6-sulphatoxymelatonin, a metabolite of the hormone melatonin shown to participate in the modulation of sleep cycles. The 6-sulphatoxymelatonin will be assessed in urine samples collected upon awakening in the morning and in the late evening, as a marker of melatonin production. In addition, sleep/activity rhythms and sleep quality will be measured by wrist actigraphy. Performance of the muscular system will be assessed by examination of muscular strength and quantifying of gene expression in the skeletal muscle tissue samples. Health status and age-induced reduction in immune function are to be analysed via the balance of pro- and anti-inflammatory immune markers in the plasma and skeletal muscle, body composition, bone density and physical fitness.
RESUMEN
Regular physical activity, recommended by the WHO, is crucial in maintaining a good physical fitness level and health status and slows down the effects of aging. However, there is a lack of knowledge of whether lifelong endurance running, with a volume and frequency above the WHO limits, still brings the same benefits, or several negative effects too. The present study aims to examine the protentional benefits and risks of lifelong endurance running training in Master male athletes, as this level of physical activity is above the WHO recommendations. Within the study, four main groups of participants will be included: (1) endurance-trained master athletes, (2) endurance-trained young athletes, (3) young sedentary adults, and (4) elderly sedentary. Both groups of athletes are strictly marathon runners, who are still actively running. The broad spectrum of the diagnostic tests, from the questionnaires, physical fitness testing, and blood sampling to muscle biopsy, will be performed to obtain the possibility of complexly analyzing the effects of lifelong endurance physical activity on the human body and aging. Moreover, the study will try to discover and explain new relationships between endurance running and diagnostic parameters, not only within aging.