Osteoporosis, a public health problem, is mainly determined on the basis of bone mineral density (BMD). The rs1800247 polymorphism of the osteocalcin gene is associated with BMD. The results of one recent Polish study led us to the examination of a possible connection between polymorphism and bone ultrasound parameters in the Hungarian population, including elite athletes. A total of 302 subjects participated in the study. Genotype analysis was carried out via a DNA chip, and anthropometric measurements were taken according to the International Biological Program. Sixty-three (63) of the participants were also measured by ultrasound bone densitometer. The genotype frequencies of osteocalcin polymorphism in the total sample were: 59.9% for hh; 36.1% for Hh; and 3.97% for HH. We separated the 63 subjects by the presence or absence of H allele, and there were no significant differences between the two groups, either in the anthropometric, or in the ultrasound parameters. In grouping the sample by genotypes, no differences were detectable in any of the bone characteristics. Compared to the controls, athletes had significantly higher results in all of the bone ultrasound values. The polymorphism of the osteocalcin gene showed no effect on bone quantity in the examined Hungarian population.

Endurance athletes often aim to improve their aerobic metabolism. The aim of this pilot study was to examine if malic acid and L-citrulline supplementation can improve aerobic metabolism and lactate elimination. Nine young (23.9 ± 1.9 years) recreational male athletes participated in this study. Following a standardised breakfast and a body composition analysis (InBody720), 6000 mg of citrulline and 3000 mg of malic acid or a placebo of 300 mL of water were consumed on three separate days in a cross-over design using a double-blind method. Sixty minutes after the supplementation, participants completed a ramp bicycle spiroergometer protocol (35 W/3 min) until reaching a respiratory exchange ratio (RER) of 1.1, followed by a 9 min active recovery. Cadence, heart rate (HR), rate of perceived exertion (RPE), respiratory parameters and lactate levels were registered. The RPExHR value was calculated to accurately characterise exhaustion. During the exercise protocol, citrulline supplementation induced significantly lower RER values at 70-105-140 W compared to malic acid and the placebo, respectively. There was no difference in lactate levels neither during rest nor at RER 1.1. RPExHR rate values were significantly lower after malic acid supplementation compared to placebo at 175 and 210 W. Power at RER 1.1 was higher after malic acid (+4 W) and citrulline (+5 W) supplementation. Although the supplementation failed to decrease lactate levels, lower RER and RPE values may indicate a performance-enhancing benefit.

Laboratory-based assessment of cardiorespiratory function is a widely applied method in sports science. Most performance evaluations focus on oxygen uptake parameters. Despite the well-established concept of oxygen deficit introduced by Hill in the 1920s, relatively few studies have examined its behavior during submaximal exercise, with limited exploration of deficit dynamics. The present study aimed to analyze the behavior of oxygen deficit in young female handball players (N = 42, age: 15.4 ± 1.3 years) during graded exercise. Oxygen deficit was estimated using the American College of Sports Medicine (ACSM) algorithm, restricted to subanaerobic threshold segments of a quasi-ramp exercise protocol. Cardiorespiratory parameters were measured with the spiroergometry test on treadmills, and body composition was assessed via Dual Energy X-ray Absorptiometry (DEXA). Cluster and principal component analyzes revealed two distinct athlete profiles with statistically significant differences in both morphological and physiological traits. Cluster 2 showed significantly higher relative VO₂ peak (51.43 ± 3.70 vs. 45.70 ± 2.87 mL·kg⁻¹·min⁻¹; p < 0.001; Cohen’s d = 1.76), yet also exhibited a greater oxygen deficit per kilogram (39.03 ± 16.71 vs. 32.56 ± 14.33 mL·kg⁻¹; p = 0.018; d = 0.80). Cluster 1 had higher absolute body mass (69.67 ± 8.13 vs. 59.66 ± 6.81 kg; p < 0.001), skeletal muscle mass (p < 0.001), and fat mass (p < 0.001), indicating that body composition strongly influenced oxygen deficit values. The observed differences in oxygen deficit profiles suggest a strong influence of genetic predispositions, particularly in cardiovascular and muscular oxygen utilization capacity. Age also emerged as a critical factor in determining the potential for adaptation. Oxygen deficit during submaximal exercise appears to be a multifactorial phenomenon shaped by structural and physiological traits. While certain influencing factors can be modified through training, others especially those of genetic origin pose inherent limitations. Early development of cardiorespiratory capacity may offer the most effective strategy for long-term optimization.