Metabolic control level and glucose variability in adolescents with type 1 diabetes during low and high-intensity exercise.

OBJECTIVE: The main purpose of this study was to characterize the determinants of metabolic changes in young type 1 diabetes (T1DM) and to determine glycemic variability during low and high-intensity exercise. PATIENTS AND METHODS: 20 young male T1DM patients were divided into two subgroups characterized by levels of glycated hemoglobin (HbA1c): HbA1c<7.3% (better HbA1c subgroup, n=10) and with levels HbA1c>7.3% (worse HbA1c subgroup, n=10). All participants performed a maximal oxygen uptake test and two efforts of various intensities (45 minutes of aerobic exercise and 30 minutes of mixed aerobic-anaerobic intensity exercise). Continuous glucose monitors (CGM) were used to control the glucose concentration. RESULTS: Changes in biomarkers describing the metabolic response were similar in both groups. A comparison of applied efforts exhibited that maximal capacity effort resulted in the highest values of blood glucose (BG) at the end (150.9-160.6 mg/dl) and 1 hour after the exercise (140.2-161.3 mg/dl). BG concentration before, during, 1 hour, and 24 hours after each exercise was insignificantly higher in the worse Hb1Ac group. CONCLUSIONS: HbA1c levels are insufficient to confirm whether the applied effort is performed in acceptable glycemic values. The CGM monitors allow for precise control of BG variations and accurate planning of physical activity by adjusting the insulin and carbohydrate consumption dose.

Effects of moderate- vs. high-intensity interval training on physical fitness, enjoyment, and affective valence in overweight/obese female adolescents: a pre-/post-test study.

OBJECTIVE: The aim of this study was to compare the effects of 12-week moderate-intensity interval training (MIIT) vs. high-intensity interval training (HIIT) on body composition, physical fitness, and psychological valence in overweight/obese (OW/OB) female adolescents. PATIENTS AND METHODS: Thirty-eight OW/OB female students were randomized into HIIT (n=13), MIIT (n=13) or control (n=12) groups. The participants underwent a 12-week interval-training program at 100% to 110% and 60% to 75% of maximal aerobic speed for HIIT and MIIT, respectively. The control group kept their usual physical activity without completing the training program. Pre- and post-training measurements were performed to assess body composition, aerobic capacity, and anaerobic performance (using selected tests evaluating speed, jumping ability, and strength). Ratings of perceived exertion and the feeling scale were evaluated every three weeks. Enjoyment was measured at the end of the program. A two-way analysis of variance with repeated measurements was applied to test for "group×time" interactions for body composition, physical fitness, and affective variables. RESULTS: Significant "group×time" interactions were detected for aerobic and anaerobic performance, body composition indices, and the feeling scale. HIIT resulted in more noticeable improvements in body composition and physical performance than MIIT, while no significant changes were found in the control group. Throughout the program, the feeling score has progressively increased in the MIIT group but decreased in the HIIT group. Ratings of the perceived exertion have increased in both groups, more noticeably in the HIIT group. At the end of the program, the MIIT group showed a higher enjoyment score. CONCLUSIONS: Despite offering better body composition improvement and physical fitness enhancement, HIIT offered lesser enjoyment and affective valence than MIIT in OW/OB female adolescents. MIIT might be an alternative time-efficient protocol for improving health in this population.

Skinfold thickness variation and associations with cardiorespiratory fitness in male soccer players of different ages.

OBJECTIVE: The aim of the present study was to examine skinfold thickness (SKF) distribution in youth and adult male soccer players regarding cardiorespiratory fitness (CRF) and the role of age. PATIENTS AND METHODS: Participants were youth [n=83, age 16.2 (1.0) years, mean (standard deviation)] and adult male soccer players [n=121, 23.2 (4.3) years], who were tested for SKF on 10 anatomical sites and Conconi test was used to assess velocity at maximal oxygen uptake (vVO2max). RESULTS: A between-within-subjects analysis of variance revealed a small interaction between the anatomical site and age group on SKF (p=0.006, η2=0.022), where adolescents had larger cheek (+0.7 mm; p=0.022; 95% confidence intervals - CI  - 0.1, 1.3), triceps (+0.9 mm; p=0.017; 95% CI 0.2, 1.6) and calf (+0.9 mm; p=0.014; 95% CI 0.2, 1.5) SKF, while adults had larger chin (+0.5 mm; p=0.007; 95% CI 0.1, 0.8) SKF, and no difference was observed for the rest of the anatomical sites. No difference between adolescent and adult age groups was observed in average SKF (SKFavg) [9.0 (2.7) vs. 9.1 (2.5) mm; difference -0.1 mm; 95% CI, -0.8, 0.6; p=0.738]. Compared to adults, adolescents had a lower SKF coefficient of variation (SKFcv) [0.34 (0.10) vs. 0.37 (0.09); difference-0.03; 95% CI, -0.06, -0.01; p=0.020] and subscapular-to-triceps ration (STR) [1.08 (0.28) vs. 1.29 (0.37); difference-0.21; 95% CI, -0.31, -0.12; p<0.001]. The largest Pearson moment correlation coefficient between vVO2max and SKF was shown in the subscapular (r=-0.411; 95% CI, -0.537, -0.284; p<0.001) and the smallest in the patellar anatomical site (r=-0.221; 95% CI, -0.356, -0.085; p=0.002). In addition, vVO2max correlated moderately with SKFavg (r=-0.390; 95% CI, -0.517, -0.262; p<0.001) and SKFcv (r=-0.334; 95% CI, -0.464, -0.203; p<0.001). CONCLUSIONS: In summary, CRF was related to the thickness of specific SKF and the magnitude of thickness variation by the anatomical site (i.e., the smaller the variation, the better the CRF). Considering the relevance of specific SKF for CRF, their further use would be recommended for monitoring physical fitness in soccer players.

How to end up on the podium after running a 6-days-run with type 1 diabetes mellitus - A case study and literature review.

BACKGROUND: An increasing number of people living with type 1 diabetes mellitus (T1DM) are pushing their physical limits to compete at the sport's highest level. Muscle, liver, and glycogen metabolism can be normal in athletes with diabetes with good glucose management, and modifications to insulin dose and nutrition can facilitate exercise performance. CASE PRESENTATION: We report on a 66-year-old runner with insulin-dependent T1DM. He has run over 90 marathons and ultra-marathons. Thanks to an insulin pump and continuous glucose monitoring, he has completed forty-eight 24-hour runs with an average performance of 133.8 km. Over the years, the runner increased his monthly running volume significantly and decreased his glycated Hemoglobin type A1C (hba1c) levels. Meanwhile, a significant association between monthly running kilometers and hba1c levels could be shown. At the age of 66 years, he finished his sixth 6-day-run in third place overall by covering a total distance of 467.424 km. CONCLUSIONS: These findings show that it is possible to participate in ultra-endurance events while suffering from T1DM without glucose derailing. With a good understanding of the disease and its impact on an individual's body, we can curtail the preparation and execution phases of ultra-endurance events to allow athletes to compete with minimal risk.

Performance improvement in sport through vitamin D - a narrative review.

OBJECTIVE: It is well known that vitamin D deficiency can lead to various health problems. However, it is not common knowledge among athletes and doctors that vitamin D deficiency is prevalent in sports. This deficiency can severely impact performance, while vitamin D supplementation can alleviate this effect and potentially improve performance. MATERIALS AND METHODS: This narrative review aims to compile the current state of knowledge about the importance of vitamin D in increasing performance for active people. To this end, we searched the 'Scopus' and 'PubMed' databases for the terms 'vitamin D - athlete - performance' with an end date of 30 June 2022. RESULTS: Study results indicated that the therapeutic impact of vitamin D on aerobic capacity, recovery, strength and sprint performance remains controversial. CONCLUSIONS: Based on the previous findings on recovery, strength and performance, 4,000-5,000 IU of vitamin D per day may be a safe dose that can improve athletic performance.

The effects of cognitive behavioral therapy on selected physical, physiological parameters, exercise and nutritional behaviors in diabetic persons.

OBJECTIVE: Due to the high prevalence of diabetes in the world, it seems that one of the most important strategies to prevent and treat this disease are lifestyle changes. The present study aimed to investigate the effects of cognitive behavioral therapy on selected physical and psychological parameters, exercise, and nutritional behaviors in diabetic patients. PATIENTS AND METHODS: This was a cross-sectional study of volunteers with type 2 diabetes. Patients were randomized into two groups: an intervention (n=32) and a control group (n=31). The Beck Physical Activity Questionnaire was used to assess physical activity in combination with the Beck Depression Inventory and the Pittsburgh Sleep Quality Index to assess the levels of depression and the quality of sleep. Cognitive behavior therapy (CBT) training consisted of six sessions of cognitive behavioral therapy interventions. The intervention consisted of a face-to-face individual counseling session. The patients received a special diet according to their basal metabolic rate (BMR). At all sessions, dietary advice was reviewed, and during the treatment period, they were asked to record their diet and physical activity. Body composition and blood samples were measured before and after three months of the experiment for both groups. RESULTS: Blood glucose, blood lipid profiles (except high-density lipoprotein), lifestyle, behavior patterns and body composition were significantly improved following CBT intervention (p≤0.05). CONCLUSIONS: CBT can play a key role in improving physiological and psychological parameters in diabetic patients.

Autoimmune hepatitis in monozygotic twins - a case report.

OBJECTIVE: Autoimmune hepatitis is a chronic liver disease caused by a dysfunctional immune system. It is widely believed that autoimmune hepatitis accumulates in families. We found that autoimmune hepatitis does accumulate in monozygotic twins. CASE REPORT: We present middle-aged monozygotic female twins developing autoimmune hepatitis consecutively within two years. Both twins had developed Graves' disease and were treated with carbimazole before the onset of autoimmune hepatitis. Both were cigarette smokers. The twins were treated with budesonide and azathioprine, which normalised liver parameters. CONCLUSIONS: This case report supports the hypothesis that a genetic factor might be of great importance in the aetiology of autoimmune hepatitis.

The effects of daytime melatonin ingestion on arousal and vigilance vanish after sub-maximal exercise: a pilot study.

OBJECTIVE: Daytime melatonin ingestion is known to induce sleep at rest, which may affect arousal and vigilance. Physical exercise is known to produce an increase in core temperature and circulating cortisol which can enhance arousal and vigilance. The effect of submaximal exercise on vigilance and arousal following acute melatonin ingestion has not yet been studied. The present study aimed at investigating the effect of submaximal exercise on vigilance and arousal following daytime melatonin ingestion. PATIENTS AND METHODS: Eight physical education students undertook 45 min of submaximal exercise (at 60% of maximal aerobic speed) on a treadmill after melatonin-(6 mg) or placebo ingestion, in a randomized and counterbalanced order. RESULTS: Heart rate (HR), rectal temperature (Tre), felt arousal scale (FAS), and thermal sensations (TS) were recorded at baseline (pre-exercise), immediately after exercise (post-exercise), and after 30 min of recovery (30 min post-exercise). Blood was sampled for lactate and cortisol. At 30 min post-exercise, the Tre, HR, blood pressure, lactate, FAS, and TS were measured. The participants performed vigilance tests pre-exercise, post-exercise and 30 min post-exercise. Daytime melatonin ingestion affected arousal and vigilance in the pre-exercise period (p < 0.05) but had no effect on Tre, HR, blood pressure, lactate, TS, arousal, and vigilance measured 30 min post-exercise (p > 0.05). CONCLUSIONS: The negative effects of melatonin ingestion on vigilance and arousal vanished after a 45 min of submaximal exercise. The hypnotic effect of melatonin observed in the pre-exercise dissipated in the post-exercise period, possibly due to the significant elevation of Tre, HR, and cortisol at the end of submaximal exercise.

Factors associated with perceived performance drops and musculoskeletal injuries in Brazilian recreational triathletes.

OBJECTIVE: The aim of the study was to investigate sleep characteristics, use of supplements, and training volume of recreational triathletes, and to verify possible associations with perceived performance drops and occurrence of injuries. MATERIALS AND METHODS: Recreational triathletes (n=942) answered a questionnaire inquiring about their demographic characteristics, performance, injuries and training volume. RESULTS: When comparing athletes who slept more (9-10 hours) with those who slept less, less sleep was associated with a higher prevalence of perceived performance drops. Regarding difficulties in initiating sleep, the absence of initiating difficulties (p<0.001) was a protective factor against perceived performance drops. Regarding weekly training volume, compared to those who trained more than 20 hours, training less than 3 hours (p<0.001), 3-5 hours (p<0.001), or 12-14 hours (p<0.001) were protective factors against perceived performance drops. Concerning training volume and injuries, we found that compared to those who trained more than 20 hours, training 18-20 hours (p<0.001), 15-17 hours (p<0.001), 12-14 hours (p<0.001), 6-8 hours (p<0.001), or 3-5 hours (p<0.001) were protective factors against injuries. CONCLUSIONS: Triathletes with a lower sleep quantity and those who have difficulties initiating sleep frequently experience drops in performance. Training volumes can influence both performance and the likelihood of injuries.

Differences in pacing during cycling and running in ultra-triathlons - The example of 'Swissultra'.

OBJECTIVE: The knowledge of the most predictive split discipline and the pacing during a triathlon race is of utmost importance for planning an ultra-triathlon race. This study aimed at investigating the pacing during cycling and running splits in three different multi-stage ultra-triathlon race formats (i.e., Quintuple, Deca, and Double Deca Iron ultra-triathlon with 5x, 10x and 20x the daily distance of a full Ironman-distance triathlon). SUBJECTS AND METHODS: A total of 48 male ultra-triathletes competing in Quintuple (n=14), Deca (n=25), and Double Deca (n=9) Iron ultra-triathlon "swissultra" between 2016 and 2019 in Switzerland were analyzed. For each race day, we calculated the total performance (sum of all laps time), average individual performance (average of all laps time within a race day) and pacing variation (coefficient of variation of race laps time) for cycling and running. Discipline (cycling and running) and race distance (Quintuple, Deca, and Double Deca Iron ultra-triathlon) were used as independent parameters. The primary outcome variables were the time performance (daily and total) and the pacing variation. We applied two general linear models (GLM): the first model was a one-way ANOVA comparing total and daily performance by race distance, and the second model was a two-way ANOVA (race distance´ discipline) using pacing variation (average pace oscillation) as a dependent variable. RESULTS: The first GLM identified a significant race distance effect for total performance in both cycling (F = 375.6; p < 0.001; ηp2 = 0.943) and running (F = 267.8; p < 0.001; ηp2 = 0.922) with Double Deca Iron ultra-triathlon being the fastest and Quintuple Iron ultra-triathlon the slowest. The GLM for daily average performance showed no significant effect of race distance on cycling performance (F = 0.171; p = 0.843; ηp2 = 0.008), but on running performance (F = 6.408; p = 0.004; ηp2 = 0.222). The two-way GLM comparing pacing variation showed a significant effect for race distance (F = 11.81; p<0.001; ηp2 = 0.344) with Deca presenting larger pace variation than Quintuple and Double Deca Iron ultra-triathlon in both cycling and running, but not for discipline (F = 0.067; p=0.797; ηp2 = 0.001), nor for interaction (F = 1.469; p=0.241; ηp2 = 0.061). CONCLUSIONS: Athletes achieved a stable cycling performance independent of the length of the race, and the cycling split had an influence on the subsequent running split depending upon the length of the race.

Effects of aerobic and strength training on depression, anxiety, and health self-perception levels during the COVID-19 pandemic.

OBJECTIVE: This study aimed at comparing the depression and anxiety levels, and health self-perception during the coronavirus disease 2019 pandemic among subjects who practice aerobic, strength, and mixed (aerobic and strength) exercises and nonsports participants. MATERIALS AND METHODS: We included 304 Brazilians of both sexes in this cross-sectional study. All participants were recruited through online advertisement and completed a self-administered questionnaire regarding the personal information, level of restriction adopted, physical activity, and mood state screening (Patient Health Questionnaire-9 and General Anxiety Disorder-7). We divided the participants into four groups: strength sports group (CrossFit or strength training), aerobic/endurance sports groups (running, cycling, triathlon, or swimming), mixed sports groups (individuals who practice endurance and strength sports), and nonsports group. RESULTS: The Kruskal-Wallis test showed a significant effect of the group on the depression and anxiety levels. Meanwhile, the post-hoc comparisons showed a significantly lower depression level in the mixed and aerobic sports groups than in the strength sports and nonsports groups, and a significantly lower anxiety level in the mixed and aerobic sports groups than in the nonsports group. Furthermore, participants in the mixed, strength, and aerobic sports groups presented a better level of health self-assessment than the nonsports group, and those in the mixed sports group had a better level of health self-assessment than the strength or aerobic sports groups. CONCLUSIONS: Individuals practicing aerobic exercises present lower depression and anxiety levels than those practicing strength training and are inactive. However, individuals who practice strength exercises and aerobics have the best levels of health perception.

Temperature and barometric pressure are related to running speed and pacing of the fastest runners in the 'Berlin Marathon'.

OBJECTIVE: The influence of environmental conditions, such as temperature, barometric pressure, humidity, precipitation, sunshine and cloud cover on marathon running has been widely investigated. However, the influence of such conditions on the pacing of elite marathoners has not been considered yet. The present study aimed to investigate whether environmental conditions are related to the running speed and pacing of the fastest marathoners competing in the fastest racecourse in the world, the 'Berlin Marathon'. SUBJECTS AND METHODS: A total of 668,735 finishers (520,715 men and 148,020 women) competing between 1999 and 2019 in the 'Berlin Marathon' were analyzed by comparing elite and recreational runners. The associations between time-adjusted averages of the environmental conditions, the race times and running speeds were investigated. The runners were divided into performance groups consisting of recreational (all runners) and elite runners (the top 100, the top 10 and the top 3) which were separately analyzed for male and female participants. RESULTS: During race days, the temperature increased while humidity decreased showing a strong negative correlation between the two variables. For all runners, the average running speed through the race showed a strong negative correlation with temperature and a strong positive correlation with the level of humidity. Faster runners experienced lower temperatures and higher humidity levels than slower runners. When the performance groups were analyzed, temperature and humidity remained correlated to a similar extent for the top 100 but dropped dramatically for the top 10 and top 3, suggesting a weaker influence. In addition, barometric pressure showed a positive correlation with running speed in the top 100 and top 3 groups. CONCLUSIONS: Temperatures increased during race days while humidity decreased and both variables were negatively and significantly correlated. Faster runners experienced lower temperatures and higher humidity levels, while slower runners experienced higher temperatures and lower humidity levels which had a stronger negative impact on running speeds. Running speed was also significantly and positively correlated with barometric pressure in elite runners.

The aspects of sex, age and nationality in winter swimming performance.

OBJECTIVE: Winter swimming is a new sport discipline. Very little is known, however, about the sex differences, origin, participation and performance of the world's best winter swimmers. Therefore, the study aimed to investigate sex differences in performance and age. Furthermore, it should be determined which country has the fastest swimmers, the highest numbers of participants and the most successful age group athletes in winter swimming. SUBJECTS AND METHODS: A total of 6,477 results from the 25 m events of the IWSA (International Winter Swimming Association) World Cups from 2016-2020 was collected from the official website of IWSA. Data were analyzed using a generalized linear model (GLM) with a gamma probability distribution and identity link function. The 25 m events were carried out in head-up breaststroke style, freestyle and butterfly. The nationalities were grouped into six groups, the five nationalities with the highest number of participants in the 25 m competitions and one group with the other nationalities. The mean time of 25 m races by sex and country of the total sample was compared. For the top 10 comparisons, the best ten athletes from the six groups were selected. The mean time of each top 10 groups was compared by sex and nationality. RESULTS: Men were faster than women for all categories. Swimmers in age group 15-29 years were the fastest, where females were the fastest in age group 15-19 years and males in age group 20-29 years. Women from both Russia and Estonia and men from both Russia and China were the fastest. Both Russian and Chinese males were the fastest in all water categories in the top 10 section in the 25 m events. CONCLUSIONS: In summary, males were faster than females in the IWSA World Cups between 2016 and 2020. The age group of 15-29 years old athletes was the most successful while females had their age of peak performance earlier than males. Russian and Estonian males and Russian females were the overall fastest in the 25 m events in all water categories. Future studies should investigate the optimal anthropometric characteristics of male and female winter swimming sprint athletes and whether there are distinct areas in Russia, Estonia and China, where many international winter swimming athletes originate.

Comparison of the levels of depression and anxiety during the first and fourth waves of coronavirus disease-2019 pandemic in Brazil.

OBJECTIVE: To compare the levels of depression, anxiety, physical activity, and mobility restrictions between the first wave in June 2020 and the fourth wave in January 2022 of the coronavirus disease-2019 (COVID-19) pandemic in Brazil. PATIENTS AND METHODS: Brazilian citizens answered a self-administered questionnaire that included questions related to personal information, mobility restriction levels, physical activity levels, and the status of mood disorders in June 2020 (n=1853) and January 2022 (n=728). RESULTS: The levels of mobility restrictions (p<0.001), anxiety (p<0.001), and depression (p<0.001) significantly decreased from 2020 to 2022. In June 2020, 23.2% of the participants presented moderate to severe anxiety, and in January 2022, this percentage decreased to 14.8%. In June 2020, 29.6% of the participants presented moderate to severe depressive symptoms, and in January 2022 this percentage decreased to 19.3%. On the contrary, physical activity levels significantly increased between 2020 and 2022 (p<0.001). CONCLUSIONS: During the fourth wave of the COVID-19 pandemic, participants were less restricted and more physically active than in the first wave. Furthermore, anxiety and depression levels were significantly lower in the fourth wave than in the first wave. Despite this reduction, levels of anxiety and depression remain high; therefore, the authors suggest measures to encourage physical activity and promote mental health.

Impact of the COVID-19 pandemic on competitive swimming performance.

OBJECTIVE: This article aims to conduct a comparison of swimming performance during short course national championships (25-m) from 2019 and 2020 (before and during the pandemic). MATERIALS AND METHODS: The data points from the championships will be compared for 5 European countries: Poland, Spain, Russia, Turkey, and Denmark. Times achieved in the finals were calculated by the analysis of variance. Post hoc pairwise comparison analysis was performed using Tukey's test. The analysis plan included the assessment of the main effects and the effect of interactions in the groups of women and men. The strength of the effect was expressed by the partial eta-squared ratio. RESULTS: Two main trends were observed in the results. The first was a greater variation in the results in the group of men than in women (12-5 differences). The second was the development and improvement of sports performance in symmetrical strokes (69% improvement in recorded times measured during the pandemic, e.g., in Poland, women on 50-m breaststroke and butterfly Δ = 0.52, p <0.001 and Δ = 0.32, p = 0.034, men on 50-m and 100-m butterfly Δ = 0.34, p = 0.003 and Δ = 1.21, p <0.001). CONCLUSIONS: The main conclusion of our analysis is that the pandemic influenced the development of sports performance in symmetrical techniques, i.e., in breaststroke and butterfly.

Association between lowering restriction levels during the coronavirus outbreak and physical activity among adults: a longitudinal observational study in Brazil.

OBJECTIVE: The COVID-19 pandemic has had significant consequences on public health and lifestyle and has negatively affected mental health and the level of physical activity worldwide. This study examined the impact of reopening fitness centers and nonessential services and introducing flexible measures to ensure social distancing on physical activity and mental health. MATERIALS AND METHODS: This was a longitudinal study. A self-administered questionnaire, including personal, behavioral, physical activity, perception of health, and mood state disorder information, was answered by 128 Brazilians in June 2020 (during severe restrictive measures) and again in April 2021 (after fitness centers and nonessential services were reopened). RESULTS: The restriction level adopted in April 2021 was significantly lower than that in June 2020 (p<0.001). The level of physical activity (p<0.001) and health status perception (p<0.001) decreased from June 2020 to April 2021. The median values for depression and anxiety did not differ across the study period. CONCLUSIONS: The level of physical activity was reduced during the COVID-19 pandemic, and anxiety and depression were not improved following less restrictive social distancing measures and the reopening of fitness centers. Thus, the return to a prepandemic level of physical activity and mental health status may not be automatic. The results presented herein suggest that the decrease in physical activity observed in the population may be challenging in the postpandemic period.

Effect of two incremental intensity field tests on wellness indices, recovery state, and physical enjoyment in soccer players.

OBJECTIVE: Competitive athletes must undergo fitness testing to monitor athlete progress and to create appropriate, progressive training programs. However, fitness testing adds to training stress; therefore, impacts of testing on wellness and recovery must be considered in test selection. This study investigated the effects of two incremental field tests [VAMEVAL test (T-VAM) and 20-m maximum shuttle test (20-m MST)] on wellness, total quality of recovery (TQR) and physical enjoyment (PE) in competitive soccer players. SUBJECTS AND METHODS: Twenty-two soccer players (20.9±1.5 years) completed two T-VAM and two 20-m MST in a randomized order on separate days with a 1-week interval between tests. TQR and wellness indices (sleep, fatigue, stress and muscle soreness) measures were collected before and 24 hours after each test. Heart rate (HR) was continuously monitored during each test. Rating of perceived exertion (RPE) and PE were assessed after each test. RESULTS: T-VAM resulted in higher PE, TQR and wellness scores than 20-m MST (p<0.05). T-VAM and 20-m MST resulted in similar HR and maximal aerobic speed. For T-VAM, TQR was correlated (p<0.01) with RPE and wellness indices. For 20-m MST, TQR was correlated (p<0.01) with wellness indices. HRmax and RPE were not correlated with wellness indices, TQR or PE. CONCLUSIONS: Overall, T-VAM and 20-m MST produced similar aerobic fitness testing results, but athletes responded more favorably to T-VAM. Coaches can use T-VAM for evaluating aerobic fitness while maximizing well-being and physical enjoyment among soccer players.

Comparison of sleep characteristics during the first and second period of restrictive measures due to COVID-19 pandemic in Greece.

OBJECTIVE: The first wave of coronavirus pandemic and concomitant restrictive measures affected sleep. We slept more than usual, but the quality was worse. As the pandemic continues, a second period of restrictive measures was initiated, and no data exist about their impact on sleep. The aim of this study was to compare quantity and quality of sleep between the two periods of restrictive measures, due to the Coronavirus Disease-19 (COVID-19) pandemic in Greece. MATERIALS AND METHODS: A web-based survey using a short 13-item questionnaire was created and was distributed online. This included information about demographic and professional data, quantitative and qualitative characteristics of sleep, degree of abidance in lockdown measures, and data about COVID-19 infection or close contact with active confirmed cases. RESULTS: A total of 1,078 questionnaires were evaluated (first period, n=963; second period, n=115). Sleep duration was shorter during the second lockdown (mean difference -0.51h; 95% confidence interval, (CI), -0.82, -0.19, p=0.002). Compared to usual habits, sleep increased in first wave (mean difference +0.37h; 95% CI, 0.26, 0.47; p<0.001) and decreased in second wave (mean difference -0.35h; 95% CI, -0.60, -0.09; p=0.009). Regarding quality of sleep, less participants reported good quality of sleep during the second wave compared to the first (p=0.006). Finally, compliance to restriction measures was lower and the prevalence of confirmed illness or close contact with COVID-19 cases among participants was higher during the second period than during the first one (p<0.001 and p=0.028, respectively). CONCLUSIONS: Our data showed that sleep duration increased during the first lockdown and decreased in the second one, when compared to usual habits. Moreover, sleep quality progressively deteriorated, as the restrictive measures due to coronavirus pandemic continued.

Effects of high-intensity interval training and plyometric exercise on the physical fitness of junior male handball players.

OBJECTIVE: This study analyzed the effects of high intensity interval training (HIIT) combined with plyometric exercise on the physical fitness of junior male handball players. PATIENTS AND METHODS: Subjects (age ~17 years) were randomly divided between experimental (n=17) and control (n=15) groups. During the 8-week intervention, the experimental group replaced a part of their regular regimen by HIIT, combined with plyometric exercise. Assessments in both groups before and after the intervention included: squat jump (SJ), countermovement jump (CMJ), sprint performance (5 m, 10 m, 20 m and 30 m), change of direction tests (Illinois modified test [Illinois-MT] and T-half test), 20-m shuttle run, and repeated sprint T-test. RESULTS: The two-way analyses of variance revealed significant group-time interactions (all p<0.05), favoring the intervention group in 5 m, 10 m, 20 m and 30 m sprint (d=0.33, 8.3%; d=0.52, 7.6%; d=0.57, 6.8%; and d=0.58, 8.8%, respectively), T-half (d=0.25, 5.1%), Illinois-MT (d=0.47, 4.2%), SJ and CMJ (d=0.34-0.39, 34-4-34.9%), repeated sprint T-test best time, mean time and total time (d=0.83, 6.9%; d=0.62, 7.4%; and d=0.61, 7.2%, respectively), 20 meter shuttle run test aerobic maximum speed and predicted maximal oxygen intake (d=0.36, 7.5%; d=0.19, 9.4%, respectively). CONCLUSIONS: HIIT combined with plyometrics can aid in the development of physical fitness abilities, which are extremely important to junior male handball players.