Changes in Stress and Appetite Responses in Male Power-Trained Athletes during Intensive Training Camp

Effects of Ingesting Food Containing Heat-Killed Lactococcus lactis Strain Plasma on Fatigue and Immune-Related Indices after High Training Load: A Randomized, Double-Blind, Placebo-Controlled, and Parallel-Group Study

Lactococcus lactis strain Plasma (LC-Plasma) is a unique lactic acid bacterium that activates plasmacytoid dendritic cells (pDCs). We evaluated the effect of LC-Plasma on fatigue indices and dendritic cells activity in athletes after 14 days’ continuous exercise load. Thirty-seven participants were divided into two groups and consumed placebo (PL) or LC-Plasma capsules (containing 100 billion cells) daily for 14 days. Maturation markers on dendritic cells, blood parameters, physiological indices, and fatigue-related indices were recorded on days 1 and 15 (before and after exercise). Cumulative days of symptoms relating to physical conditions were also recorded during the continuous exercise period. We observed that CD86 as a maturation marker on pDCs was significantly higher and that cumulative days of fatigue were significantly fewer in the LC-Plasma group than in the Placebo group on day 15. We also conducted 2 h ergometer exercise on day 15 to evaluate fatigue. The results showed that autonomic fatigue parameters (LF/HF) were significantly lower in the LC-Plasma group. These results suggest that LC-Plasma supplementation alleviates fatigue accumulation and increases pDC activity caused by a continuous high training load.

Non-Contact Negative Mood State Detection Using Reliability-Focused Multi-Modal Fusion Model

Negative mood states include tension, depression, anger, fatigue, and confusion, which represent the weak internal emotions of a human. Negative mood states exert adverse impact on individuals' ability to make rational decisions, which entails the practicable method of negative mood state detection. The most commonly used negative mood state detection methods are based on the psychological scale, which requires additional work and brings inconvenience to the subject in the application scenarios. To overcome this challenge, this paper proposes a novel non-contact negative mood state detection method according to the knowledge of affective computing. The POMS-net model is used to extract temporal-spatial features from visible and infrared thermal videos, and the negative mood state detection is realized using data reliability-focused multi-modal fusion. The proposed method is verified using the HDT-BR dataset collected in the aerospace medicine experiment "Earth-Star II" and the VIRI public dataset. The experimental results on the datasets verify that our method outperforms the comparison methods.

Increasing Meal Frequency in Isoenergetic Conditions Does Not Affect Body Composition Change and Appetite During Weight Gain in Japanese Athletes

For athletes to gain body mass, especially muscle, an increase in energy consumption is necessary. To increase their energy intake, many athletes consume more meals, including supplementary meals or snacks. However, the influence of meal frequency on changes in body composition and appetite is unclear. The aim of this study was to determine the effect of meal frequency on changes in body composition and appetite during weight gain in athletes through a well-controlled dietary intervention. Ten male collegiate rowers with weight gain goals were included in this study. The subjects were randomly classified into two groups, and dietary intervention was implemented using a crossover method. During the intervention period, all subjects were provided identical meals aimed to provide a positive energy balance. The meals were consumed at a frequency of either three times (regular frequency) or six times (high frequency) a day. Body composition was measured using dual energy X-ray absorptiometry, and the visual analog scale was used for the evaluation of appetite. In both trials, body weight, fat-free mass, and fat mass significantly increased; however, an interaction (Trial × Time) was not observed. Visual analog scale did not vary between trials. Our data suggest that partitioning identical excess dietary intakes over three or six meals does not influence changes in body composition or appetite during weight gain in athletes.

Changes in Psychological Anxiety and Physiological Stress Hormones in Korea National Shooters

Psychological anxiety and physiological stress hormone management is closely related to an athlete’s performance, especially in shooting competitions. Thus, we aimed to investigate the changes in saliva stress hormones according to anxiety scores of Korean elite shooters immediately before a shooting competition. Seventy-two Korean national shooting athletes (Rifle = 62, Pistol = 8, Shotgun = 2) were recruited for the present study. The physiological stress hormones were assessed based on cortisol and immunoglobulin A level in saliva. The psychological stress was assessed based on Beck Anxiety Inventory (BAI) questionnaire. Cortisol concentration and cortisol secretion rate were significant higher in severe anxiety group. Secretory immunoglobulin A (SIgA) concentration and SIgA secretion rate did not significant different in among the groups. A positive correlation was found between BAI score and cortisol concentration. These findings provide preliminary evidence indicating that psychological anxiety affects physiological stress and therefore may have a negative effect on athletes’ performance. Thus, research is needed to develop a strategy to reduce physiological stress in these athletes.

Dietary Intake and Energy Expenditure During Two Different Phases of Athletic Training in Female Collegiate Lacrosse Players

Kumahara, H, Ohta, C, Nabeshima, E, Nakayama, A, Mine, S, and Yamato, T. Dietary intake and energy expenditure during two different phases of athletic training in female collegiate lacrosse players. J Strength Cond Res 34(6): 1547-1554, 2020-This study aims to investigate the state of nutrient intake and energy expenditure (EE) among various phases of periodization in female collegiate lacrosse players. A total of 17 Japanese female collegiate lacrosse players (age: 20.0 ± 0.9 years) were enrolled in this study. Physical activity (PA) and dietary intake were assessed over each 1-week period during the training preparatory phase (P-phase) and transition phase (T-phase). The exercise training-related EE (EEE) and EE associated with other daily living activities (i.e., nonexercise activity thermogenesis [NEAT]), were measured using accelerometers and heart rate (HR) monitoring using the flex-HR method. The total daily EE during the P-phase was significantly higher than that of the T-phase (2,168 ± 248 vs. 1744 ± 138 kcal·d; p < 0.01); however, no significant differences were observed in the total energy intake. Moreover, EEE during the P-phase was significantly higher than that of the T-phase, whereas no significant difference was found in NEAT. Furthermore, no significant differences were noted in any macronutrient intake variable observed between the 2 phases (protein:fat:carbohydrate ratio: 12.6 ± 1.5:32.9 ± 3.9:54.1 ± 5.1% in the P-phase vs. 12.1 ± 1.7:30.7 ± 3.9:55.7 ± 5.2% in the T-phase). The carbohydrate and protein intake were below recommended levels during the P-phase. Conversely, the saturated fatty acid ratio was higher than the dietary goals for disease prevention. Based on the changes in the PA volume observed during different training phases, female collegiate lacrosse players did not attain optimal nutrient intake required for optimal athletic performance and health.

Influence of Sunlight and Oral D3 Supplementation on Serum 25(OH)D Concentration and Exercise Performance in Elite Soccer Players

The aim of this study was to evaluate the influence of natural sun exposure and six weeks of a high dose of vitamin D supplementation on vitamin D, testosterone and cortisol serum concentrations as well as speed, power and VO_2max in professional soccer players. Materials: The study was conducted from January to September. At the beginning of the study, 33 professional soccer players were enrolled; however, only 28 subjects (height 181.5 cm; body mass 77.81 ± 8.8 kg; body fat 12.38% ± 2.4% and muscle mass 40.27 ± 5.3 kg) completed the study. The research consisted of three stages. The first one, lasting 10 days, was conducted in January during a training camp in the south part of Cyprus at a latitude of 34 33°, where participants experienced natural sun exposure; it was called a winter sun exposure (WSE) period. The second stage, which was a supplementation period (SP), lasted 6 weeks, during which all subjects were randomly assigned either to an experimental group—EG (n = 15)—or a placebo group—PG (n = 13)—and were administered 6000 IU/d cholecalciferol or a placebo, respectively. The third stage took place in September, after summertime (summer sun exposure—SSE). The data of the 25(OH)D, free and total testosterone (fT, tT), cortisol as well as 5 and 30 m sprint tests (STs), power of the left leg (PLL) and VO_2max were evaluated before and after the WSE period, the SP and SSE. Results: In January, the baseline value of vitamin D in 12 subjects was ≤20 ng/mL, and 14 of them had levels between 20–30 ng/mL and 2 individuals >30 ng/mL. After the WSE period, significant changes in 25(OH)D, fT, tT and cortisol concentration, as well as in the 5 m ST, were observed. After the SP, in the EG, significant changes were found in 25(OH)D, fT, tT and the 5 m ST. Furthermore, a positive correlation between the concentration of 25(OH) fT and tT was observed. After SSE, 2 out of 28 players had <20 ng/mL 25(OH)D, 12 of them had 25(OH)D between 20 and 30 ng/mL and 14 of them had 25(OH)D between 30 and 50 ng/mL. Significant differences in 25(OH)D, fT, tT concentration and the 5 m ST performance were observed following SSE compared with the WSE period. Conclusion: Due to the serum level of 25(OH)D demonstrated by most participants at the beginning of the study and after summertime, all-year-round supplementation with high doses of vitamin D seems to be a reasonable solution to enhance high 25(OH)D concentration in blood and physical performance. In the middle of the winter, almost half of the soccer players were serum deficient of 25(OH)D. After ten days of sun exposure and 6 weeks of vitamin D supplementation, the concentration of 25(OH)D significantly increased, as did testosterone and results in the 5 m sprint test also improved. Therefore, athletes should be constantly monitored for serum levels of 25(OH)D throughout the year and should be supplemented if deficiencies or insufficient amounts of this vitamin occur.

Changes in Parameters of Oxidative Stress, Immunity, and Behavior in Endurance Athletes During a Preparation Period in Winter

Michalickova, D, Minic, R, Kotur-Stevuljevic, J, Andjelkovic, M, Dikic, N, Kostic-Vucicevic, M, Slanar, O, and Djordjevic, B. Changes in parameters of oxidative stress, immunity, and behavior in endurance athletes during a preparation period in winter. J Strength Cond Res 34(10): 2965-2973, 2020-The current study monitored markers of immunological and oxidative status in 9 male elite endurance athletes: V[Combining Dot Above]O2max: 68 ± 11 ml·kg·min, age: 24 ± 2.5 years, and training loads: 128 ± 21 metabolic equivalents-h·wk during a 3-month preparation period in winter (January-March). Self-rated state of moods evaluation (by Profile of Mood States questionnaire) was performed, and blood samples were collected at the beginning and end of the study. Spectrophotometric methods and enzyme-linked immunosorbent assay were used for parameters' determination. The level of concanavalin A (ConA)-stimulated interferon-γ (IFN-γ) from peripheral blood mononuclear cells (PBMCs) was increased (562 [147-852] vs. 1,097 [451-1842] pg·ml, p = 0.013). Also, the level of transforming growth factor-1 (TGF-β1) in serum was elevated (2.5 [1.4-5.1] vs. 7.2 [4.9-8.2] ng·ml, p = 0.015). There was no change in the level of peptidoglycan (PGN)-stimulated interleukin (IL)-10 from PBMCs. There were no significant changes in PBMCs proliferation/viability on stimulation with ConA and PGN during the study. No changes in superoxide dismutase, prooxidative-antioxidative balance, total oxidant status (TOS), and thiobarbituric acid reactive substances were observed along the study. Total antioxidant status (TAS) was increased (910 ± 174 vs. 1,090 ± 102 μmol·L, p = 0.018), and activity of paraoxonase (PON1) was decreased (523 ± 295 vs. 335 ± 183 U·L, p = 0.003) at the end of the study. Advanced oxidation protein products were increased (25 ± 7.9 vs. 42 ± 7.6 μmol·L, p = 0.011). The self-rated sense of vigor significantly declined (20 ± 2.1 vs. 14 ± 3.4, p = 0.045). In conclusion, 3 months of regular training in winter induced prominent changes in cytokines, biomarkers of oxidative stress, and antioxidative enzyme activity. These changes might increase susceptibility of athletes to disease and muscle damage and consequently lead to performance reduction.