This study examined how the body and mood respond to intense physical effort in elite male and female rowers. Athletes completed a maximal rowing test after one week of hard training. Researchers collected blood samples before and after exercise to measure stress hormones and brain-related chemicals. They also used a short questionnaire to assess how the athletes felt emotionally before the test. The goal of the study is to better understand how physical and mental fatigue develop in well-trained athletes, and whether men and women respond differently.

This observational cohort study was designed to characterize acute physiological and psychological responses to maximal exertion following a high-load training period in elite male and female rowers. The main aim was to investigate how accumulated training fatigue affects hormonal and neurochemical responses to intense effort, and whether these responses differ by sex.

Participants were national-level athletes undergoing a standardized 7-day training camp, during which they completed identical high-intensity training sessions. On day 8, all participants performed a 2000-m maximal rowing ergometer test under controlled conditions. Blood samples were collected at three time points: before exercise (PRE), immediately post-exercise (POST), and 1 hour post-exercise (1H).

Biomarkers analyzed in serum included cortisol, total testosterone, serotonin (5-HT), dopamine (DA), gamma-aminobutyric acid (GABA), and tryptophan. The testosterone-to-cortisol (T/C) ratio was used as an index of anabolic-catabolic balance, while the 5-HT/DA ratio was examined as a neurochemical indicator of central fatigue.

In parallel, mood state was assessed once prior to the exertion test using the standardized Profile of Mood States (POMS) questionnaire. This provided insight into psychological readiness and emotional state entering maximal effort.

A total of 28 athletes (12 females, 16 males) completed the full protocol. There were no missing data. The study did not involve any interventions, randomization, or masking. Statistical analyses included repeated-measures ANOVA for time and group effects, and calculation of within-group effect sizes (Cohen's d).

Although no biospecimens were retained beyond initial analysis, serum samples were processed and stored short-term according to laboratory standards. The study followed ethical approval procedures and informed consent was obtained from all participants. No external monitoring, third-party auditing, or source data verification was implemented, as this was a single-site, non-interventional academic study.

The data collected provide a multidimensional profile of physiological and mood-related responses to intense physical effort under conditions of cumulative fatigue. These findings may inform future monitoring strategies in high-performance sport and support individualized recovery planning.

Inclusion Criteria:

Aged 19-25 years National-level competitive rower Minimum 5 years of structured rowing training Currently in full training and competition season Completed 7-day standardized high-load training program Provided written informed consent

Exclusion Criteria:

Use of medications or supplements affecting hormonal or neurochemical markers Known endocrine, neurological, or psychiatric disorders Injury or illness interfering with training or testing Incomplete participation in the training camp or testing protocol

All participants were recruited and tested at the Central Sports Centre - Olympic Preparation Center (COS OPO) in Wałcz, Poland, during a national team training camp under standardized conditions.

Individual participant data (IPD) will not be shared. Data will be used only for internal analysis and dissemination in scientific publications in aggregate form, in accordance with ethical approval.