The impact of a 14-day altitude training camp on olympic-level open-water swimmers' sleep

Despite the common belief that sleep quality at altitude is poor, the scientific evidence to support this notion is still modest. Therefore, the purpose of the present study was to evaluate possible changes of actigraphy-based and subjective sleep parameters in a group of elite open-water swimmers during a 14-day altitude training camp (ATC) at 1500 m. The study subjects were five Olympic-level open-water swimmers (mean age: 25.0 ± 3.2 years; 3 females and 2 males). All subjects wore a wrist activity monitor and filled a sleep diary for 18 consecutive nights, 4 nights before and 14 nights during ATC. The data were then analyzed at four different time points: before ATC (PRE), the first two days of ATC (T1), and after one (T2) and two weeks of ATC (T3). Training load, assessed as the covered distance (km), session rating of perceived exertion (sRPE), and heart rate (HR), was monitored during the week before and the first and second week of ATC. No significant differences in objective and subjective scores of sleep quality were detected, whereas the sleep onset time (p = 0.018; η2p = 0.83, large) and sleep offset time (p < 0.001; η2p = 0.95, large) significantly differed among PRE, T1, T2, and T3: elite athletes started to sleep and woke up ≃ 1 h earlier the first two days of ATC compared to PRE (sleep onset time: p = 0.049; sleep offset time: p = 0.016). Further, an increase in the training volume during the two weeks of the ATC was observed, with the most time spent in a low-intensity regime and an increase in time spent in a high-intensity regime compared to PRE. Sleep quality was not negatively influenced by a 14-day altitude training camp at 1500 m in a group of Olympic-level elite swimmers despite an increase in perceived exertion during training sessions. Nonetheless, early sleep onset and sleep offset times were observed for the first two nights of ATC: elite athletes started to sleep and woke up ≃ 1 h earlier compared to the baseline nights

Hyperbaric exposure and oxidative Stress in occupational activities (HEOxS): the study protocol

Background: Hyperbaric exposure (HE) is proven to be a stressor to several mechanisms in living cells. Even if after homeostasis restoration, harmful effects are expected, in particular a presence of free radicals. These latter are the stimulus to negative phenomenon as inflammation or cancer. In Italy, with 7500 km of sea shores, a large quantity of workers is exposed to HE during occupational activities. A deep knowledge of HE and bodily effects is not well defined; hence a multidisciplinary assessment of risk is needed. To detect one or more indicators of HE a research group is organised, under the INAIL sponsorship. The research project focused on the oxidative stress (OxS) and this paper details on the possible protocol to estimate, with a large amount of techniques on several human liquids, the relationship between OxS and HE. Specific attention will be paid to identify confounding factors and their influence. Methods: Blood and urine will be sampled. Several lab techniques will be performed on samples, both targeted, to measure the level of well-known biomarkers, and untargeted. Regard the formers: products of oxidation of DNA and RNA in urine; inflammation and temperature cytokines and protein carbonyles in blood. Untargeted evaluation will be performed for a metabolomics analysis in urine. Confounding factors: temperature, body fat, fitness, allergies and dietary habits. These factors will be assessed, directly or indirectly, prior and after HE. The final scope of the project is to determine one or more indicators that relates to HE in hits twofold nature: depth and duration. Conclusion: The relationship between OxS and HE is not deeply investigated and literature proposes diverging results. The project aims to define the time dependence of biomarkers related to OxS, to rise knowledge in risk assessment in workers exposed to HE

Metabolic Biomarkers of Red Beetroot Juice Intake at Rest and after Physical Exercise

Background: Red beetroot is known to be a health-promoting food. However, little attention is placed on intestinal bioactive compound absorption. The aim of the study was to assess the urinary red beetroot juice (RBJ) intake biomarkers and possible differences in RBJ’s micronutrient absorption at rest or after physical exercise. Methods: This is a three-armed, single-blind study, involving seven healthy volunteers which were randomly divided into three groups and alternatively assigned to three experimental sessions: RBJ intake at rest, RBJ intake with physical activity, and placebo intake with physical activity. For each session, urine samples were collected before and 120, 180, and 240 min after the intake of RBJ or placebo. The same sampling times were employed for the experimental session at rest. The RBJ metabolic composition was also characterized to identify the urinary biomarkers derived from the intake. Results: 4-methylpyridine-2-carboxylic acid, dopamine-3-O-sulfate, glutamine, and 3-hydroxyisobutyrate were identified as RBJ intake biomarkers. Physical activity significantly increased only the dopamine-3-O-sulfate excretion 120 min after RBJ intake. Conclusions: Urinary dopamine-3-O-sulfate is related to RBJ dopamine content, while 4-methylpyridine-2-carboxylic acid is a betanin or betalamic acid catabolite. The different excretions of these metabolites following physical activity suggest a possible effect on the RBJ uptake depending on different transport processes through the mucosa, namely diffusion-mediated transport for dopamine and saturable transcellular transport for betalamic acid derivatives. These results open new perspectives in improving the absorption of natural bioactive molecules through physical activity