Physiologia, Volume 5, Issue 1 (March 2025) – 11 articles

Background/Objectives The plants of the Lavandula genus are widely investigated because of their significance for pharmaceuticals and food. The composition of lavender essential oil is determined by genotype and can be induced by environmental, ontogenetic factors, and morphogenetic features. Linalool and linalyl acetate are the most abundant compounds, performing essential ecological functions and participating in lavender’s therapeutic properties. This review reports on the biosynthesis of lavender oil compounds and summarises the environmental, developmental, and molecular factors contributing to essential oil composition in lavender flowers. Results Floral developmental stage and ontogeny are fundamental for optimal harvest time. The harvesting period for high-quality lavender essential oil is affected by environmental and developmental factors that influence the gene expression of monoterpene biosynthesis. Conclusions These findings indicate the appropriate features for high-quality lavender essential oil and contribute to information that may allow for the manipulation of monoterpenes biosynthesis in lavender breeding efforts. Full article

Background: Building on our previous work, this study presents a cost-effective, non-invasive methodology for recording, identifying, and analyzing plant ultrasonic emissions in dynamic environments, both indoor and outdoor. While previous research has utilized contactless microphones to compare water-stressed and hydrated plants indoors, to the best of our knowledge, no similar studies have been conducted in outdoor conditions. The objective of this study is to address the need for scalable, accessible tools for monitoring plant stress in a variety of environmental settings. Methods: Pinto bean and tomato plants were exposed to water stress conditions and monitored in both indoor and outdoor environments, with plant acoustic emissions recorded using an ultrasonic microphone. Results: The proposed methodology successfully recognized plant ultrasonic emissions even in the presence of high levels of environmental noise typical of outdoor conditions (e.g., wind, rain, or insect chirping). Conclusions: We argue that this method, with its minimal equipment requirements, is a valuable addition to the range of tools available for Plant Acoustics research, offering the potential for non-invasive monitoring in a variety of different environments. Full article

Background/Objectives: Volleyball training camps are known to reduce salivary secretory immunoglobulin A (s-SIgA); however, when it begins to decrease is unclear. The validity of a simple device for quantifying s-SIgA is lacking; hence, this study aimed to observe detailed s-SIgA changes during a volleyball training camp after moving to a high altitude and to investigate the difference in s-SIgA response between the two quantification methods, namely, the enzyme-linked immunosorbent assay (ELISA) and lateral flow device (LFD). Methods: Twenty-four male university volleyball players participated in the observational study. Measurements were collected at three points of the training camp (days 1, 4, and 7). The s-SIgA was quantified using conventional ELISA and the new LFD method. Results: The s-SIgA concentrations quantified using the two methods decreased significantly by day 4 (p < 0.05) and continued to decrease until day 7 (p < 0.05). A significant positive correlation was found between the s-SIgA concentrations quantified using the LFD and ELISA (p < 0.05, r_s = 0.319). Conclusions: These results indicate that a high-altitude volleyball training camp may suppress oral immune function by day 4 and that the evaluation of s-SIgA concentration using the LFD method is beneficial. A faster and easier method for assessing s-SIgA could contribute to athletes’ condition management strategies. Full article

Background: Substance Use Disorders (SUDs) are chronic conditions characterized by high relapse rates and significant psychological, physical, and social complications. Despite the availability of traditional pharmacological and psychotherapeutic interventions, many individuals struggle to maintain abstinence. Recently, physical activity (PA) has emerged as a promising complementary intervention. This review aims to examine the existing evidence on the effects of PA in individuals with SUDs, with a particular focus on neurobiological mechanisms. Methods: A narrative review was conducted on 30 September 2024, searching relevant keywords on PubMed, Web of Science, Google Scholar, and Scopus. Randomized clinical trials, cohort studies, reviews, and meta-analyses published between 1988 and 2024 were considered. Results: Fifty studies were included. Key themes included the role of PA in inducing neuroadaptation in individuals with SUDs, which is crucial for relapse prevention and impulse control, and the effects of PA depending on the type of PA and the specific SUD. Neurobiological modifications related to PA are of particular interest in the search for potential biomarkers. Additionally, studies explored the effects of PA on cravings, mental health, and quality of life. The review overall discusses the psychological changes induced by PA during SUD rehabilitation, identifies barriers to participation in PA programs, and suggests clinical and organizational strategies to enhance adherence. Conclusions: Physical activity is a promising adjunctive therapy for the management of Substance Use Disorders. Long-time longitudinal studies and meta-analyses are needed to sustain scientific evidence of efficacy. The success of PA programs moreover depends on overcoming barriers to adherence, including physical, psychological, and logistical challenges. Full article

Background/Objectives: This study examines the utility of the 3-min all-out test (3MT) in determining exercise intensity domains through critical speed (CS), offering a practical alternative to traditional $V{O}_{2max}$-based methods. Methods: Eighteen trained runners completed both the 3MT and a graded treadmill test. CS, $V{O}_{2max}$, and $H{R}_{max}$ were measured and compared to markers such as ventilation threshold (VT), gas exchange threshold (GET), lactate threshold (LT), onset of blood lactate accumulation (OBLA), CS, and $V{O}_{2max}$, which are threshold markers for defining six exercise intensity domains. Results: Results demonstrate that CS reliably distinguishes among six exercise intensity domains with greater precision and less variability than heart rate (HR) or $V{O}_2$-derived metrics. Notably, HR was unable to differentiate between high-intensity domains, highlighting its limitations for performance prescription. Compared to $V{O}_{2max}$ testing, the 3MT offers a simpler, non-invasive, and time-efficient approach to identifying training zones and monitoring performance. CS effectively delineated moderate-to-heavy, heavy-to-severe, and severe-to-extreme intensity domains, with strong correlations to performance thresholds. The findings emphasize the accessibility and reliability of the 3MT, particularly in overcoming the logistical challenges of traditional testing methods. Conclusions: This research underscores the potential of the running 3MT as a valuable tool for individualized training prescription and performance monitoring in both research and applied sports contexts, paving the way for a broader adoption in athletic training methodologies. Full article

Background/Objectives: Plyometrics is a widely used method to enhance the physical performance of athletes. Studies have demonstrated that the effectiveness of plyometrics increases when combined with other training methods. This study aims to determine whether the direct combination of plyometric and sprint training improves linear sprint speed and change-of-direction speed in youth soccer players. Methods: Twenty-eight male youth soccer players were randomly assigned to an intervention group (INT, n = 14, 12.9 ± 0.4 years) and a control group (CON, n = 14, 12.9 ± 0.7 years). The INT group performed two sessions per week, each including nine drop jumps, followed by a hurdle jump and one sprint. The CON group only performed nine sprints without any jumps. Both groups continued their regular soccer training over the 20-week intervention period. Pre- and post-intervention tests included 5 m, 10 m, and 30 m linear sprints and a modified agility t-test for change-of-direction speed. Results: Largest improvements were observed in the INT group (5 m = 6.7%, 10 m = 4.8%, 30 m = 2.7%, change-of-direction speed = 3.6%, 3.1%). A significant difference between the groups was noted for the 10 m sprint distance (p = 0.02). Furthermore, moderate to large correlations between linear sprint speed and change-of-direction speed were found in both groups (r = 0.33–0.82). Conclusions: Results suggest that the direct combination of plyometric training and sprint training over a 20-week period can improve both linear sprint speed and change-of-direction speed in youth soccer players, thus enhancing physical performance. Full article

Background/Objectives: Functional near-infrared spectroscopy (fNIRS) may help quantify changes in brain haemodynamics during sport-related concussions (SRCs). This study compared post-match prefrontal cortex (PFC) brain haemodynamics measured by fNIRS during the King–-Devick test (K-DT) with players suspected of having sustained an SRC. It was hypothesized that changes in the K-DT would correspond with brain haemodynamic processes. Methods: Twenty-two male and female collegiate rugby players (six males and twenty-two females; age range: 18–22) completed a baseline K-DT+fNIRS assessment. Over the course of two to three matches, all participants were invited to complete at least one post-match K-DT+fNIRS assessment. If a player was suspected of having sustained an SRC, they were re-assessed with the K-DT+fNIRS. If a participant who was not suspected of having sustained an SRC performed worse on the K-DT post-match, they were included in the participant category of ‘concussion’ for the analysis. A repeated measures ANOVA was performed. Test–retest reliability was calculated using the intra-class correlation coefficient (ICC). A Pearson correlation coefficient (r) assessed the linear relationship between the changes in the K-DT and the measurements of the left and right PFC. Results: Differences were identified in the K-DT for the players with a suspected concussive injury post-match (χ2(1) =5.0; p = 0.0253; z = −2.0; p = 0.0431; d = 0.16). There were also significant differences between the baseline and post-match results for all concussed players in the right PFC (t(8) = 250; p = 0.0371; d = 0.92) and for the concussed females in the right PFC (t(6) = 2.78; p = 0.0319; d = 0.52). There were no correlations between the K-DT and PFC values in the suspected concussed group. Conclusions: The SRC group had decreased cognitive performance and a notable change in PFC activation, while the non-concussed group showed an increase in the activation in the PFC and no change in cognitive performance scores. This represents a possible acute adjustment in brain haemodynamics and provides insight into how SRCs can negatively impact cognitive performance. Full article

The maximal rate of fat oxidation (MFO, in g∙min⁻¹) and the relative exercise intensity at which it occurs (FAT_max, as %V̇O_2max) are indexes of metabolic flexibility. The time-consuming, graded exercise protocol required for MFO/FAT_max determination hinders the extensive use of these indexes for individualized exercise prescription and monitoring. Purpose: validate ramp testing for MFO and FAT_max measures in postmenopausal women. Methods: Seventeen healthy women (age: 54 ± 4 years, BMI 22 ± 3 kg·m⁻², and V̇O_2max 36.4 ± 5.3 mL·min⁻¹), who were 4 ± 3 years from menopause, performed on a cycle-ergometer, a ramp, and a graded incremental test. Based on V̇O₂ and respiratory exchange ratio from the ramp and graded protocol (i.e., the 5th minute of each step), MFO and FAT_max were determined. Data from the two protocols were compared using paired t-tests, linear regression, and Bland–Altman analysis. Results: The MFO measured with a ramp protocol was not different from (0.24 ± 0.09 vs. 0.20 ± 0.08 g·min⁻¹, p = 0.10), and moderately associated with, that of the graded protocol (r² = 0.46). FAT_max occurred at similar exercise intensity for both protocols (47.8 ± 5.1 vs. 47.5 ± 4.3 %V̇O_2max, p = 0.91, r² = 0.52). The comparison of MFO and FAT_max across the protocols yields a non-significant bias but a relatively large limit of agreement (respectively, 0.05 g·min⁻¹, LOA = −0.08, and 0.19 g·min⁻¹; 0.3 %V̇O_2max, LOA = −7.8, and 10.6 %V̇O_2max). Conclusions: In postmenopausal women, ramp testing offers a valid alternative to the graded protocol for identifying MFO and FAT_max. The availability of a time- and cost-efficient approach, which can be incorporated into standard ramp incremental testing, can facilitate using these indexes of metabolic flexibility in research and medicine. Full article

Pregnancy is followed by complex and intense physiological changes in the maternal body, whose goal is to provide all the needs of the mother and the growing fetus. The endocrine system and thermoregulation integrate physiologic responses and play an important role in maintaining homeostatic conditions during exercise in pregnancy. Changes and adaptations during exercise in pregnancy are conditioned by the influence of numerous metabolic and biochemical events, which act on the target tissues through physiological mechanisms. Many hormones are released during exercise and a variety of cells are responsible for a number of different responses. Pregnancy involves changes in thermoregulation that lead to an increase in heat production and its preservation. Physiological mechanisms that enable the release of excess body temperature in order for the body to maintain an ideal temperature during exercise are increased, such as sweating and vasodilation of blood vessels. The reaction of a mother to exercise training depends on the exercise duration and intensity of training, the nutrient profile, and the level of fitness. Exercise has many improving effects on functional aspects of tissues and organs, resulting in improved health and/or performance. Full article

Background/Objectives: The purpose of this study was to determine the effects of various muscle taping applications on running efficiency. Methods: Recreational runners (N = 14; 7 women; age = 22.80 ± 4.61 years; BMI = 25.08 ± 3.97 kg/m²) completed four bouts of treadmill running at a preferred speed. Each bout used a different taping technique, as follows: control (no tape), athletic tape, Kinesio tape, and a novel spring-type technique of Kinesio tape. Oxygen consumption, muscle activation of the rectus femoris and biceps femoris, and stride frequency were observed during each bout to assess running efficiency. The data for these variables were analyzed with repeated-measures ANOVAs (α = 0.05). Results: There were no differences among any of the four conditions for oxygen consumption (p = 0.232, η² = 0.103), muscle activation of the rectus femoris (p = 0.173, η² = 0.118) or biceps femoris (p = 0.085, η² = 0.184), or stride frequency (p = 0.230, η² = 0.107). Conclusions: None of the three taping methods tested in this study had a significant impact on oxygen consumption, agonist muscle activation, or stride frequency during short running bouts at a preferred speed compared to a control condition. There appeared to be no ergogenic benefit to the use of these taping techniques during this manner of activity. Runners opting to use a taping method to enhance joint stability at the knee during preferred-intensity running activity may do so without any substantial impact on their running efficiency. Full article