Isokinetic Muscular Strength and Aerobic Physical Fitness in Recreational Long-Distance Runners: A Cross-Sectional Study.

ABSTRACT: Andrade, MS, Silva, WA, de Lira, CAB, Mascarin, NC, Vancini, RL, Nikolaidis, PT, and Knechtle, B. Isokinetic muscular strength and aerobic physical fitness in recreational long-distance runners: A cross-sectional study. J Strength Cond Res 36(3): e73-e80, 2022-Muscular strength, bilateral asymmetry, and imbalance between antagonist muscles have been considered as risk factors for knee injuries. Moreover, muscular strength has also been associated with aerobic performance. The aim of the study was to investigate bilateral muscular symmetry and muscular strength balance assessed by isokinetic dynamometry in recreational long-distance runners and to verify whether knee muscular strength would be associated with maximal oxygen uptake (V̇o2max), anaerobic threshold (AT), and running economy (RE). Thirty-nine runners (male [n = 24]: age, 30 ± 8 years; height, 176.0 ± 7.3 cm; body mass, 70.3 ± 8.0 kg; race pace below 4:30 min·km-1 and female [n = 15]: age, 31 ± 7 years; height, 163.0 ± 3.8 cm; body mass, 55.9 ± 4.7 kg; race pace below 5:00 min·km-1) participated in this study. Comparing the conventional knee balance ratio with the literature recommendation (60%), male runners presented significantly lower values for the nondominant side (55.5 ± 7.3%; p = 0.001; d = 0.85; confidence interval [CI] = 0.47 to 1.20) but not for the dominant side (58.1 ± 6.8%; p = 0.208; d = 0.37; CI = -0.12 to 0.86). Female runners presented lower values for both sides (52.1 ± 7.1%; p = 0.001; d = 1.55; CI = 0.86 to 2.20 and 50.7 ± 8.0%; p = 0.001; d = 1.62; CI = 0.90 to 2.30 for dominant and nondominant sides, respectively). Female and male runners presented nonfunctional ratio imbalance and asymmetry of bilateral strength. Strength outcomes were not associated with V̇o2max, AT, or RE. In conclusion, recreational runners were characterized by an imbalance in muscular strength between knee flexor and extensor muscles, which was more obvious in female runners, and by symmetrical thigh muscle strength values. Moreover, muscular isokinetic knee flexor and extensor muscle strength was not associated with aerobic fitness parameters.

Return to classes impact on mental health of university students during the COVID-19 pandemic.

BACKGROUND: The coronavirus disease 2019 (COVID-19) pandemic and the necessary social isolation and distancing measures - that were adopted to prevent spreading the virus, including the suspension of university classes - negatively impacted the mental health of young adults. The aim of the current study was to investigate whether returning to online classes, even not presential, during the social isolation of the COVID-19 pandemic, affected the mental health of university students. METHODS: Forty students (10 men and 30 women) (age, 22.3 ± 3.8 years; body mass, 62.5 ± 17.8 kg; height, 165.6 ± 8.7 cm) from undergraduate health courses participated in the study. The students answered a self-administered questionnaire designed to gather personal and quarantine information as well as information about the frequency of depression (PHQ-9) and anxiety (GAD-7) symptoms. The questionnaire was answered before and after the return to online classes. RESULTS: There was a significantly lower frequency of depression symptoms after the return to online classes (Z = -2.27; p = 0.02). However, there was no difference in anxiety symptoms before and after returning to online classes (Z = -0.51; p = 0.61). CONCLUSIONS: Return to online classes positively impacted the mental health (decrease of frequency of depression symptoms) of university students. Future studies are needed to observe whether the changes observed after returning to school are maintained over time.

Physical Activity Levels and Mental Health during the COVID-19 Pandemic: Preliminary Results of a Comparative Study between Convenience Samples from Brazil and Switzerland.

Background and objectives: It has been suggested that the COVID-19 pandemic impaired people's moods and general levels of physical activity, but the way in which each country is coping with the situation may result in different outcomes. The aim of the present study was to compare the mental health and physical activity levels between residents of Brazil and Switzerland during the social distancing period associated with COVID-19 pandemic. Materials and Methods: A self-administered questionnaire aiming to assess personal, quarantine, physical activity, and mood state disorders data was answered by 114 participants (57 from each country) of both sexes. Results: Swiss participants presented a higher frequency of people (47.4%) not abiding by social distancing measures compared to Brazilian participants (1.8%; p < 0.001, effect size = 0.56). There were no significant differences between the participants from the two countries regarding physical activity levels (p = 0.09). The Swiss presented a higher frequency (78.9%) of people without symptoms of depression compared to Brazilians (31.6%; p < 0.001, effect size = 0.48). The Swiss also presented a higher frequency (77.2%) of people without symptoms of anxiety compared to Brazilians (35.1%; p < 0.001, effect size = 0.43). There was a significant association between the restriction level and depression symptoms (p = 0.01, effect size = 0.25) but not with anxiety symptoms (p = 0.21, effect size = 0.16). Conclusions: According to the preliminary results, Brazilians presented a much higher frequency of depression and anxiety symptoms, which can be explained by characteristics other than the restriction level.

Effect of Intermittent Hypoxic Training Followed by Intermittent Hypoxic Exposure on Aerobic Capacity of Long Distance Runners.

Effects of intermittent hypoxic training (IHT) are still controversial and detraining effects remain uninvestigated. Therefore, we investigated (a) whether IHT improves aerobic capacity; (b) whether aerobic detraining occurs post-IHT; and (c) whether intermittent hypoxic exposure (IHE) at rest reduces a possible aerobic detraining post-IHT. Twenty eight runners (21 men/7 women; 36 ± 2 years; maximal oxygen uptake [V[Combining Dot Above]O2max] 55.4 ± 1.3 ml·kg·min) participated in a single-blinded placebo-controlled trial. Twice a week, 1 group performed 6 weeks of IHT (n = 11), followed by 4 weeks of IHE (n = 11) at rest (IHT+IHE group). Another group performed 6 weeks of IHT (n = 10), followed by 4 weeks of normoxic exposure (NE, n = 9) at rest (IHT+NE group). A control group performed 6 weeks of normoxic training (NT, n = 7), followed by 4 weeks of NE (n = 6) at rest (NT+NE group). Hematological and submaximal/maximal aerobic measurements were conducted in normoxia at pretraining, posttraining, and postexposure. Hemoglobin concentration did not change, but lactate threshold and running economy improved in all groups at posttraining (p ≤ 0.05 vs. pretraining). Ventilatory threshold, respiratory compensation point, and V[Combining Dot Above]O2max increased after IHT (IHT+IHE group: 7.3, 5.4, and 9.2%, respectively; IHT+NE group: 10.7, 7.5, and 4.8%; p ≤ 0.05 vs. pretraining), but not after NT (-1.1, -1.0, and -3.8%; p > 0.05 vs. pretraining). Such IHT-induced adaptations were maintained at postexposure (p > 0.05 vs. postexposure). In conclusion, IHT induced further aerobic improvements than NT. These additional IHT adaptations were maintained for 4 weeks post-IHT, regardless of IHE.

Amateur Female Athletes Perform the Running Split of a Triathlon Race at Higher Relative Intensity than the Male Athletes: A Cross-Sectional Study.

Maximal oxygen uptake (V˙O2max), ventilatory threshold (VT) and respiratory compensation point (RCP) can be used to monitor the training intensity and the race strategy, and the elucidation of the specificities existing between the sexes can be interesting for coaches and athletes. The aim of the study was to compare ventilatory threshold (VT), respiratory compensation point (RCP), and the percentage of the maximal aerobic speed (MAS) that can be maintained in a triathlon race between sexes. Forty-one triathletes (22 men and 19 women), 42.1 ± 8.4 (26 to 60) years old, that raced the same Olympic triathlon underwent a cardiorespiratory maximal treadmill test to assess their VT, RPC, and MAS, and race speed. The maximal oxygen uptake (V˙O2max) (54.0 ± 5.1 vs. 49.8 ± 7.7 mL/kg/min, p < 0.001) and MAS (17 ± 2 vs. 15 ± 2 km/h, p = 0.001) were significantly higher in male than in female athletes. Conversely, there were no sex differences according to the percentage of V˙O2max reached at VT (74.4 ± 4.9 vs. 76.1 ± 5.4%, p = 0.298) and RCP (89.9 ± 3.6 vs. 90.6 ± 4.0%, p = 0.560). The mean speed during the race did not differ between sexes (12.1 ± 1.7 km/h and 11.7 ± 1.8 km/h, p = 0.506, respectively). Finally, men performed the running split at a lower percentage of speed at RCP than women (84.0 ± 8.7 vs. 91.2 ± 7.0%, respectively, p = 0.005). Therefore, male and female athletes accomplished the running split in an Olympic triathlon distance at distinct relative intensities, as female athletes run at a higher RCP percentage.

Effects of twelve weeks of dance Exergames on the quality-of-life variables of elderly Brazilian women enrolled in a community program.

BACKGROUND AND PURPOSE: Exercise-based interventions can be a safe alternative to improve and maintain physical and mental health during the aging process. The aim of the present study was to evaluate the effects of a 12-week training program with Dance Exergames on the mood and functional fitness profile of elderly women. METHODS: The sample (n = 22) was divided into Exergames (EG, n = 9, 70.6 ± 1.6 years) and Control Groups (CG, n = 13, 73.6 ± 2.2 years). Evaluations were carried out before and after the interventions. Each participant played, in pairs, the electronic game Dance Central 3, with the XBOX 360 Kinect console (Slim, Microsoft, USA). The EG trained for 12 weeks (24 sessions), with two weekly sessions of 50 min and the CG performed manual activities workshops. RESULTS: In functional fitness, both exercise training with exergame (EG) and the intervention model for the CG did not produce significant effects regarding interaction (group*time). Mood state presented significant effect of time intervention regarding tension (p = <0.001), depression (p = 0.001), anger (p = 0.030), fatigue (p = 0.001), and mental confusion (p = 0.004). CONCLUSION: Twelve weeks of training with a dance exergame (for, EG) and manual activities (for, CG) is enough to promote improvements in the mood state of healthy elderly women. This is an interesting result, as it shows that social interaction is as important a component as improving functional capacity.

Age-related performance determinants of young swimmers in 100- and 400-m events.

BACKGROUND: Swimming performance is influenced by several parameters, such as body composition, anthropometric and physiological parameters. However, the level of relative contributions of these variables to swimming performance in different age groups is unclear. Characteristics of body composition, anthropometry and neuromuscular variables were evaluated to identify determinant variables on 100- and 400-meter freestyle swimming events. METHODS: Sixty swimmers from both sexes participated in the study. They were divided into three groups: 11, 12 years old (G1), 13, 14 years old (G2) and 15 to 23 years old (G3). Pearson's correlation and Stepwise multiple regression models were fitted to determine the relationships between performance and the parameters evaluated. RESULTS: Results show that age plays a major role for G1 (time [100-m]=236.737-13.323 [age], r2=0.51 and Time [400-m]=831.070 - 39.014 [age], r2=0.35). Lean body mass, muscular power and anthropometric parameters were determinants of performance on G2 (Time [100-m]=81.964 - 0.504 [lean] - 0.566 [CMJ power] - 0.493 [trunk width], r2=0.83 and time [400-m]=592.536 - 3.471 [CMJ power] - 1.679 [length lower limbs], r2=0.57). Muscular strength and body mass were determinants of performance for G3 (time [100-m]=80.273 - 0.201 [PT knee flex 60°/s], r2=0.56 and time [400-m]=219.632 - 2.608 [handgrip strength] + 2.917 [body mass], r2=0.70). CONCLUSIONS: These results contribute to the development of proper training programs for each age group (strength and power training are important to improve performance only after 13 years old) and to determine parameters of sports selection (antropometric variables are important for 100 and 400m swimming performance).

The Performance, Physiology and Morphology of Female and Male Olympic-Distance Triathletes.

Sex differences in triathlon performance have been decreasing in recent decades and little information is available to explain it. Thirty-nine male and eighteen female amateur triathletes were evaluated for fat mass, lean mass, maximal oxygen uptake (VO2 max), ventilatory threshold (VT), respiratory compensation point (RCP), and performance in a national Olympic triathlon race. Female athletes presented higher fat mass (p = 0.02, d = 0.84, power = 0.78) and lower lean mass (p < 0.01, d = 3.11, power = 0.99). VO2 max (p < 0.01, d = 1.46, power = 0.99), maximal aerobic velocity (MAV) (p < 0.01, d = 2.05, power = 0.99), velocities in VT (p < 0.01, d = 1.26, power = 0.97), and RCP (p < 0.01, d = 1.53, power = 0.99) were significantly worse in the female group. VT (%VO2 max) (p = 0.012, d = 0.73, power = 0.58) and RCP (%VO2 max) (p = 0.005, d = 0.85, power = 0.89) were higher in the female group. Female athletes presented lower VO2 max value, lower lean mass, and higher fat mass. However, females presented higher values of aerobic endurance (%VO2 max), which can attenuate sex differences in triathlon performance. Coaches and athletes should consider that female athletes can maintain a higher percentage of MAV values than males during the running split to prescribe individual training.

Distribution of body fat is associated with physical performance of male amateur triathlon athletes.

BACKGROUND: Endurance sports are strongly associated with maximum oxygen uptake, anaerobic threshold, running economy and body fat percentage. Despite the importance for performance of the low-fat mass being a consensus in the literature, there are no data about the importance of the pattern of fat distribution. Therefore, the aim of the present study was to investigate the association between fat mass distribution with triathlon performance and physiological determinants of performance: maximal oxygen consumption (V̇O2max), ventilatory threshold (AT) and running economy (RE), and to verify the predictive value for performance of gynoid or android fat mass distribution. METHODS: Thirty-nine triathletes (38.8±6.9 years, 174.8±6.5 cm and 74.3±8.8 kg) were evaluated for anthropometric (total body mass, fat mass, lean mass, android and gynoid fat mass) and physiological (V̇O2max, AT and RE) parameters. Split and overall race times were registered. RESULTS: Overall race time relationship with gynoid fat mass (r=0.529, P<0.05) was classified as moderate and with android fat mass (r=0.416, P<0.05) was classified as low. All split times and overall race time presented significant positive correlation with only total fat mass (%) (r=0.329 to 0.574, P<0.05) and with gynoid fat mass (%) (r=0.359 to 0.529, P<0.05). Overall race time can be better predicted by gynoid fat mass (ß=0.529, t=4.093, P<0.001, r2=0.28) than by android fat mass (ß=0.416, t=2.997, P=0.005, r2=0.17). CONCLUSIONS: Fat mass distribution is associated with triathlon performance, and the gynoid fat pattern is worse for triathlon performance than the android pattern.

Effect of both dance exergame and a traditional exercise on state anxiety and enjoyment in women.

BACKGROUND: Anxiety disorders affect many people around the world and women are more affected than men. Physical exercise might be an important nonpharmacological tool to ameliorate these disorders. The aim of this study was to compare state anxiety level and enjoyment between a dance exergame session and a traditional aerobic exercise. METHODS: Twenty healthy young women completed 3 visits, on separate days. At the first visit, participants performed a graded exercise testing and familiarization procedures. In other two visits, participants completed two exercise sessions (dance exergame and traditional aerobic exercise), with similar intensities and duration. Each session lasted approximately 45 minutes. State anxiety level was evaluated before, immediately post- and 10 minutes post-sessions. Enjoyment was evaluated immediately post-sessions. RESULTS: There was a significant interaction between session and time (P<0.001), a main effect of time (P=0.007) but no significant main effect of session (P=0.057) on state anxiety level. State anxiety level immediately post (P<0.001) and 10 minutes postsession (P<0.001) were significantly lower than predance exergame session. There were no significant changes between pre-, immediately post and 10 minutes post-traditional aerobic exercise session (P>0.05). State anxiety level at immediately post dance exergame session was significantly lower than immediately post traditional aerobic exercise session (P=0.026). Dance exergame session was significantly more enjoyable than traditional aerobic exercise session (P<0.0001). CONCLUSIONS: Dance exergames might be used as a tool to reduce anxiety level in young women.

Acute effects of exergame-based calisthenics versus traditional calisthenics on state-anxiety levels in young adult men: a randomized trial.

Purpose: This study compared the acute effects of an exergame-based calisthenics (EXG) session versus a traditional calisthenics (TC) session on state anxiety levels in healthy adult men, and compared the mean heart rate, number of repetitions performed, enjoyment, and affective valence reported by the participants between sessions. Methods: Thirty-six young adult men performed two 30-min sessions of physical exercise in random order (EXG and TC). The same exercise protocol was used for each session; however, the TC session was guided by an exercise science professional. State anxiety was assessed before and immediately after each session. Heart rate was monitored during the sessions. Enjoyment and affective valence were assessed immediately after the sessions. In addition, the number of repetitions performed was recorded. Results: There was no significant interaction between sessions (EXG vs. TC) and time (pre vs. post-session) (p = 0.102), no significant effect of session (p = 0.587), and no significant effect of time (p = 0.121). Participants presented a higher mean heart rate (+ 3.5%, p = 0.020) and number of repetitions performed (+ 43.7%, p < 0.001) in the TC session compared with the EXG session. There was no difference in enjoyment (p = 0.804) and affective (p = 0.195) valence between the EXG and TC sessions. Conclusion: The EXG and TC sessions did not reduce state anxiety levels. Nor did they increase enjoyment or affective valence in healthy young adult men. However, the TC session evoked a higher mean heart rate and higher training volume than the EXG session. Supplementary Information: The online version contains supplementary material available at 10.1007/s11332-021-00841-9.

COVID-19: It's still time for health professionals, physical activity enthusiasts and sportive leagues not to let guard down.

Emerging viral diseases represent a serious issue to public and global healthcare systems and have a high potential for disease dissemination in sport/physical activity and exercise facilities. The Coronavirus disease 2019 (COVID-19) pandemic has frightened the sports and physical activity community and enthusiasts for potential transmission, dissemination, and lethality in vulnerable populations; those with chronic diseases, co-morbidities, the elderly people, and in young and healthy people. This pandemic has caused a chain reaction with cancellations of sports competitions and gymnasiums closing around the world. Currently, some sporting events are gradually resuming in certain regions of the world and also the return of competitions and training. In general, without fans and public, the sports media can only report the infection of athletes and coaching staff members. However, this situation is dynamic - the world is currently experiencing the second wave of the disease; with the safety and containment measures for the disease is changing daily. The purpose of this article is to present information concerning the COVID-19 pandemic, to clarify health issues for professionals and people connected to sport and physical activity venues, presenting information to assist in educations and the health promotion and prevention. The time is now for making changes, reviewing the actions and conducts necessary for prevention, and most importantly not letting our guard down, even as vaccines become available for all people in the world. Remembering that even after getting vaccinated, it is necessary to continue with safety measures, for example, the use of facial masks and social distance and hygiene, that is, washing your hands frequently and/or sanitizing with 70% alcohol. We can't let our guard down for COVID-19.

Physical exercise and COVID-19 pandemic in PubMed: Two months of dynamics and one year of original scientific production.

Our aim was to conduct a narrative review about physical exercise and Corona Virus Disease 2019 (COVID-19). A literature search was completed crossing the keywords "COVID-19" and "physical exercise", for a narrative review, and physical activity (PA), physical exercise, physical training, sport, physical fitness, for a systematic review; search strategy (Randomized Controlled Trial, in the last 1 year, English). The first search date was closed on 04/26/2020 and 06/26/2020. This strategy was chosen to assess the dynamics of scientific information production for the pandemic. In two months, an increase of 76%, from 12 (19.4%) to 50 (80.64%) COVID-19 articles (n = 62, 100%) was found. The main types of articles published were editorial articles (16.13%, n = 10 of 62 articles) and commentary (9.68%, n = 6 of 62 articles). The most frequent country of origin of the scientific production was the United States (12.90%, n = 8 of 62 articles), the United Kingdom (12.90%, n = 8 of 62 articles), and Brazil (11.29%, n = 7 of 62 articles). However, in 2020, there were only 2 relevant randomized controlled trials on the COVID-19 topic in the context of physical exercise. Scientific information production shows the concern of the PA science community to bring a solution to the increase in physical inactivity generated by the COVID-19 pandemic. Our findings show the dynamics of scientific production on the COVID-19, in a situation so unique such as a pandemic, denotes that the practice of PA is essential to improve and/or maintain physical and mental health.

Isokinetic Muscle Strength and Postural Sway of Recreationally Active Older Adults vs. Master Road Runners.

Trunk muscle strength and control is an important prerequisite for everyday activities among elderly people decreasing the predisposition to falls. High levels of physical exercise performed by older athletes could offer benefits to core/trunk muscle strength and postural control compared with recreational physical activities and among elderly people with lower levels of physical activity. The present study aimed to compare trunk muscle strength and postural control of older running athletes vs. older physically active adults. Participants were master road runners (RUN, n = 15, six women, 64.3 ± 3.6 years) and physically active elderly (control group, CON, n = 15, six women, 65.4 ± 5.0 years) people that were submitted to the evaluations: esthesiometer, posturography (force plate), and isokinetic test (Biodex dynamometer) of trunk muscle extension and flexion. RUN presented higher values for relative peak torque of trunk extensor muscles at 60°/s (p = 0.046) and 180°/s (p = 0.007) and relative average power during trunk extension at 60°/s (p = 0.008) and 180°/s (p = 0.004) compared to CON. CON had a higher medial-lateral oscillation speed of the center of pressure in the stable condition with eyes closed (p = 0.004) compared to RUN. RUN presented higher isokinetic torque of extensor trunk muscles and better postural control than CON. This supposedly could help with postural control and balance and contribute to the prevention of falls among the elderly. The practice of running systematically by master athletes may partially explained our findings.

Acute and Chronic Effects of Interval Training on the Immune System: A Systematic Review with Meta-Analysis.

PURPOSE: To summarize the evidence regarding the acute and chronic effects of interval training (IT) in the immune system through a systematic review with meta-analysis. DESIGN: Systematic review with meta-analysis. DATA SOURCE: English, Portuguese and Spanish languages search of the electronic databases Pubmed/Medline, Scopus, and SciELO. Eligibility criteria: Studies such as clinical trials, randomized cross-over trials and randomized clinical trials, investigating the acute and chronic effects of IT on the immune outcomes in humans. RESULTS: Of the 175 studies retrieved, 35 were included in the qualitative analysis and 18 in a meta-analysis. Within-group analysis detected significant acute decrease after IT on immunoglobulin A (IgA) secretory rate (n = 115; MD = -15.46 µg·min-1; 95%CI, -28.3 to 2.66; p = 0.02), total leucocyte count increase (n = 137; MD = 2.58 × 103 µL-1; 95%CI, 1.79 to 3.38; p < 0.001), increase in lymphocyte count immediately after exercise (n = 125; MD = 1.3 × 103 µL-1; 95%CI, 0.86 to 1.75; p < 0.001), and decrease during recovery (30 to 180 min post-exercise) (n = 125; MD = -0.36 × 103 µL-1;-0.57 to -0.15; p < 0.001). No effect was detected on absolute IgA (n = 127; MD = 47.5 µg·mL-1; 95%CI, -10.6 to 105.6; p = 0.11). Overall, IT might acutely reduce leucocyte function. Regarding chronic effects IT improved immune function without change leucocyte count. CONCLUSION: IT might provide a transient disturbance on the immune system, followed by reduced immune function. However, regular IT performance induces favorable adaptations on immune function.

Comment on: Problematic online gaming and the COVID-19 pandemic - The role of exergames.

Although significant increases in gaming may not always be beneficial, exergames (a new generation of video games also known as exergaming or active video games) appear as an alternative, feasible, attractive, and safe way to perform physical exercise for most clinical and nonclinical populations. Therefore, it is important to recognize that exergames can be considered a useful tool for coping with the COVID-19 outbreak and the recommended social distancing period.

Impact of training volume and experience on amateur Ironman triathlon performance.

PURPOSE: To investigate the association between training volume, sleep time, signs and symptoms of excessive training (overtraining), and  previous triathlon experience with overall and split race times in the Ironman distance triathlon. METHODS: Ninety-nine triathletes (19 women and 80 men) answered an online survey containing questions about anthropometric characteristics (body mass and height), weekly training volume (hours per day and days per week), previous experience in Ironman distance triathlon race, and signs and symptoms of excessive training. Data of race times of all participants were collected by a single race (the Ironman Brazil 2019 - Florianópolis). All surveys were collected between 28 and 30 days before the race. The athlete was instructed to answer the questions according to what was happening in the week before completing the survey. RESULTS: Total race time did not differ among those who trained up to 14 h per week (11:28:46±01:54:30 h:min:sec), between 15 and 20 h per week (11:37:31±01:20:26 h:min:sec) or more than 20 h per week (11:30:18±01:31:28 h:min:sec) (p = 0.922). Total race time of the triathletes who presented (12:42:22±01:49:36 h:min:sec) or no (11:23:06±01:29:02 h:min:sec) unintentional body mass loss (p = 0.006), feeling (12:46:17±02:03:13 h:min:sec) or no (11:24:09±01:28:07 h:min:sec) of decreased performance (p = 0.009) or feeling (12:08:58±01:47:12 h:min:sec) or no (11:16:34±01:24:53 h:min:sec) loss of energy (p = 0.011) in the week prior to the race were significantly different. Triathletes who had a previous experience in Ironman races achieved a better performance (11:15:21±01:32:04 h:min:sec) than those without previous experience (12:06:38±01:32:10 h:min:sec) (p = 0.010). CONCLUSION: In summary, high volumes of training (more than 20 h per week), when performed forty days before a race, may not have a positive impact on performance compared to lower volumes of training (up to 14 h per week). However, athletes who had a previous experience in Ironman race presented better results in swimming splits and overall race time. Moreover, the presence of overtraining symptoms, such as unintentional loss of weight, sensation of fatigue and/or performance decrease impact negatively triathlon performance.

A Sociodemographic Profile of Mask Use During the COVID-19 Outbreak Among Young and Elderly Individuals in Brazil: Online Survey Study.

BACKGROUND: Sociodemographic variables may impact decision making regarding safety measures. The use and selection of adequate face masks is a safety and health measure that could help minimize the spread of COVID-19 infection. OBJECTIVE: This study aims to examine sociodemographic variables and factors relating to COVID-19 that could impact decision making or the choice to use or not use face masks in the prevention and care of a possible COVID-19 infection among a large sample of younger and older Brazilian people. METHODS: An online survey composed of 14 closed-ended questions about sociodemographic variables and COVID-19 was used. A total of 2673 participants consisted of Brazilian people (aged ≥18 years) from different states of Brazil and were grouped according to age (≤59 years and ≥60 years). To compare the variables of interest (associated with wearing a face mask or not), chi-square and likelihood ratio tests were used (with P<.05 being significant). RESULTS: Most of the participants in both groups were women from the southeast region who had postgraduate degrees. Approximately 61% (1452/2378) of individuals aged ≤59 years and 67.8% (200/295) of those aged ≥60 years were not health professionals. In the group aged ≤59 years, 83.4% (1983/2378) did not show COVID-19 signs and symptoms, and 97.3% (2314/2378) were not diagnosed with COVID-19. In the older adult group, 92.5% (273/295) did not show signs and symptoms of COVID-19, and 98.3% (290/295) were not diagnosed with the disease. The majority of the participants in both groups reported using face masks, and their decision to use face masks was influenced by the level of education and their occupation as a health professional. CONCLUSIONS: Younger and older adults have worn face masks during the COVID-19 outbreak. It is difficult to measure how much of a positive impact this attitude, habit, and behavior could have on the degree of infection and spread of the disease. However, it can be a positive indicator of adherence to the population's security and safety measures during the pandemic.

Changes in Knee Vastii Muscle Activity in Women with Patellofemoral Pain Syndrome During the Menstrual Cycle.

BACKGROUND: Changes in hormonal levels during the menstrual cycle are known to affect muscle electromyographic (EMG) activity, but no studies have investigated the effect of hormonal changes on the EMG activity of muscles around the knee in patients with patellofemoral pain syndrome (PFPS). OBJECTIVE: To evaluate the EMG activity of the vastus medialis obliquus (VMO) and vastus lateralis (VL) muscles during toe rise and heel rock tasks in different phases of the menstrual cycle in women with PFPS. DESIGN: Cross sectional study. SETTING: Rehabilitation Research Center at the School of Rehabilitation Sciences of Shiraz University of Medical Sciences. PARTICIPANTS: Ten women with PFPS between 18 and 40 years of age. INTERVENTION: Not applicable. MAIN OUTCOME MEASURES: The VL/VMO amplitude ratio and differences between onset (onset VL-onset VMO) of vastii muscle activity were measured in the affected limb during rise and rock tasks in the follicular and ovulatory phases of the menstrual cycle. The signals were analyzed with MATLAB software. RESULTS: During both tasks, there were no significant changes in onset differences in vastii muscles between the ovulatory and follicular phases. However, the amplitude ratio (VL/VMO) was significantly lower in the ovulatory phase compared to the follicular phase (P = .035 for rise tasks and .010 for rock tasks). CONCLUSION: The menstrual cycle may affect some EMG parameters. These factors can be taken into account when planning sports and rehabilitation training programs.

Previous experience, aerobic capacity and body composition are the best predictors for Olympic distance triathlon performance: Predictors in amateur triathlon.

OBJECTIVE: Present study examines predictors of the overall race time and disciplines in the Olympic distance triathlon. METHODS: Thirty-nine male and six female triathletes were evaluated for anthropometric, physiological, genetic, training, clinical and circadian characteristics. Body composition, maximum capacity for oxygen uptake (V˙O2max), maximum aerobic velocity (MAV), anaerobic threshold (AT), triathlon experience (TE) and XX genotype for α-actinin 3 affected total race time (p<0.05). RESULTS: Total race time can be predicted by MAV (ß = -0.430, t = -3.225, p = 0.003), TE (ß = -0.378, t = -3.605, p = 0.001), and percentage of lean mass (%LM) (ß = -0.332, t = -2.503, p = 0.017). Swimming can be predicted by MAV (ß = -0.403, t = -3.239, p = 0.002), TE (ß = -0.339, t = -2.876, p = 0.007), and AT%V˙O2max (ß = 0.281, t = 2.278, p = 0.028). Cycling can be predicted by MAV (ß = -0.341, t = -2.333, p = 0.025), TE (ß = -0.363, t = -3.172, p = 0.003), and %LM (ß = -0.326, t = -2.265, p = 0.029). In running split, MAV (ß = -0.768, t = -6.222, p < 0.001) was the only parameter present in the best multiple linear regression model. CONCLUSION: The most important variables in multiple regression models for estimating performance were MAV, TE, AT and %LM.