Injury incidence and prevalence in elite short-course triathletes: a 4-year prospective study.

OBJECTIVE: To characterise the prevalence, incidence rate (IR) and burden of injuries in elite short-course triathletes over a 4-year training and competition period. METHODS: Fifty elite Australian triathletes were prospectively monitored for injury during four consecutive seasons (2018-2021). Injuries requiring medical attention were prospectively recorded and further subcategorised according to time loss. The IR and burden (injury IR×mean injury severity) were calculated per 365 athlete days, with sex differences in IR compared using IR ratios (IRR) from negative binomial regression models. RESULTS: Two hundred and sixty-six injuries were reported in 46 (92.0%) athletes, of which 67.3% resulted in time loss. The injury IR was 1.87 injuries per 365 athlete days (95% CI 1.70 to 2.80), and comparable between sexes (IRR 0.82, 95% CI 0.64 to 1.04, p=0.109). Most injuries (70.7%) were training related. The most frequently injured body sites were the ankle (15.8%), foot (12.4%) and lower leg (12.0%). Bone stress injuries (BSIs) were the most burdensome injury type with 31.38 days of time loss per 365 days (95% CI 24.42 to 38.34). Twenty athletes (40.0%) reported at least one bone stress injury (BSI) (range 0-3). The rate of BSIs in female athletes was three times greater compared with male athletes (IRR 2.99, 95% CI 1.26 to 7.07, p=0.013). CONCLUSION: Two-thirds of injuries reported in elite short-course triathletes resulted in time loss, with the majority occurring during training activities. Foot, ankle and other lower leg injuries had the highest incidence, with BSIs carrying the highest injury burden. The considerably higher rate of BSI observed in female athletes warrants consideration for future prevention strategies in female triathletes.

Natación artística en niñas: antropometría, genotipo y rendimiento deportivo / Artistic Swimming in Girls: Anthropometrics, Genotype and Athletic Performance

En cada deporte es importante optimizar peso y composición corporal y la genética y los datos antropométricos pueden influir en rendimiento deportivo y salud, sobre todo en deportistas menores. Este estudio analiza 60 nadadoras artísticas entre 9 y 17 años, divididas en tres grupos de edad: ≤12, 13-15 y 16-17 años. Se realizó un análisis de medidas antropométricas, edad de menarquia, genotipo relacionado con rendimiento (gen ACTN3) y resultados deportivos, con objetivo de relacionar estos parámetros entre sí en los grupos de edad. Las nadadoras de mayor edad mostraron tendencia a portar el genotipo heterocigoto RX de ACTN3. En este estudio, la práctica de este deporte podría tener impacto en índice de masa corporal, pliegue tricipital, peso y edad de menarquia. La mayor prevalencia del genotipo heterocigoto ACTN3 R577X podría ofrecer una ventaja, pero el rendimiento en competición de las nadadoras artísticas tuvo poca relación con sus medidas antropométricas. (AU)

In sport, optimizing weight and body composition is important for performance although an excessive drive for thinness can lead to diminished performance and health problems. This is especially important in the youngest athletes. This study examines 60 national competition-level Spanish artistic swimmers aged 9-17 years. Participants were divided into 3 categories: 12 years and under, 13-15 and 16-17 years. The data analysed were anthropometric measures, menarche age, genotype related to performance (gene ACTN3) and athletic performance. Relationships between athletic performance and anthropometric or genetic data were compared among the three age groups. Swimmers showed a tendency to carry the heterozygous genotype RX of the ACTN3 gene in the older age group. In this study, this sport could have an impact on body mass index, triceps skinfold, weight, menarche age, and selection of one genotype, but the performance in competition of the artistic swimmers had little linking to anthropometric measures. (AU)

Identifying risk factors and implications for beach drowning prevention amongst an Australian multicultural community.

Multicultural communities in Australia are recognised as a priority area for drowning prevention, but no evidence-based study has addressed their knowledge of beach safety. This study used an online survey tool to identify and examine risk factors relating to swimming ability, beach visitation characteristics and behaviour, and beach safety knowledge of the Australian Southern Asian community to assist in the development of future beach safety interventions. Data was obtained through 249 online and in-person surveys of people aged > 18 years. Most respondents reported poor swimming ability (80%), often swam in in the absence of lifeguards (77%), did not understand the rip current hazard (58%), but reported that they entered the water (76%) when visiting beaches. Close to one-quarter (28%) had not heard, or didn't know the purpose, of the red and yellow beach flags, which identify lifeguard supervised areas on Australian beaches. Length of time living in Australia is an important beach safety consideration for this community, with minimal differences in terms of gender and age. Those who have lived < 10 years in Australia visit beaches more frequently and are less likely to have participated in swimming lessons, be able to swim, heard of the flags or swim between them, understand rip currents, or have participated in a beach safety program. Very few (3%) respondents received beach safety information from within their own community. The importance of beach safety education and swimming lessons within the Southern Asian community should be prioritised for new and recent migrants to Australia.

Electrolytic lesions of the bilateral ventrolateral orbital cortex not only directly reduce depression-like behavior but also decreased desperate behavior induced by chronic unpredicted mild stress in rats.

BACKGROUND: Previous studies have revealed that ventrolateral orbital cortex (VLO) may play an important role in the regulation of emotional behavior. However, it is not known what effect VLO damage will have on emotion regulation. RESULTS: Data showed that damage of VLO increased the anxiety-like behavior in open field test and elevated plus maze, and decreased the depressive behavior in forced swimming test and learned helplessness test. Besides, the impulsive aggressive behaviors were also increased while the attack latency decreased after VLO lesion. What's more, damage of VLO decreased depressive behaviors induced by chronic unpredicted mild stress in rats. CONCLUSIONS: These results suggest that the integrity of VLO plays an important role in emotional regulation, and the damage of VLO may inhibit the development of depression-like behavior.

Incidence of Swimming-Induced Pulmonary Edema: A Cohort Study Based on 47,600 Open-Water Swimming Distances.

BACKGROUND: Despite increasing awareness of swimming-induced pulmonary edema (SIPE), large population-based studies are lacking and the incidence is unknown. RESEARCH QUESTION: What is the incidence of SIPE in a mixed group of competitive and recreational swimmers during a large open-water swimming event? METHODS: In four consecutive years (2016-2019), a prospective cohort study was conducted during Sweden's largest open-water swimming event, Vansbrosimningen. All swimmers seeking medical care with acute respiratory symptoms were eligible for the study. SIPE diagnosis was based on clinical findings in 2016 and 2017 and pulmonary edema assessed by lung ultrasound in 2018 and 2019. Data on patient characteristics, clinical findings, and information about the race were collected. RESULTS: Based on 47,573 consecutive swimming distances, 322 patients with acute respiratory symptoms (0.68%; CI, 0.61%-0.75%) were treated at the mobile medical unit. Of these, 211 patients (0.44%; CI, 0.39%-0.51%) received a diagnosis of SIPE. The annual incidence of SIPE was 0.34%, 0.47%, 0.41%, and 0.57%, respectively, from 2016 through 2019. Most patients diagnosed with SIPE were women (90%), despite about equal percentages of men and women participating (47% men and 53% women). The incidence of SIPE overall was 0.75% in women and 0.09% in men. The incidence increased with age, from 0.08% in the youngest age group (18-30 years) to 1.1% in the oldest age group (≥ 61 years). Based on multiple logistic regression analysis, the adjusted odds for SIPE occurring was 8.59 times higher for women compared with men and 12.74 times higher for the oldest age group compared with the youngest age group. INTERPRETATION: The incidence of SIPE over 4 years during a large open-water swimming event in Sweden was 0.44%. The incidence was higher in women than in men and increased with age.

Being a top swimmer during the early career is not a prerequisite for success: A study on sprinter strokes.

OBJECTIVES: To quantify the junior-to-senior successful transition rate in sprint swimming events in elite European performers. DESIGN: Retrospective analysis of publicly available competition data collected between 2004 and 2019. METHODS: The yearly performance of 6631 European swimmers (females = 41.8% of the sample) competing in 50 and 100 m freestyle, backstroke, breaststroke, and butterfly were included in the analysis. The junior-to-senior transition rate was determined as the number of elite junior athletes who maintained their elite status in adulthood. To investigate how the definition of elite may affect the calculation of the transition rate, we operationally defined elite athletes as those ranked in the all-time top 10, 25, 50, and 100 in their category. We also calculated the correlation between junior and senior performances. RESULTS: The average transition rates ranged, depending on the age of reference, from 10 to 26% in males and from 23 to 33% in females. The transition rate for the top 100 junior swimmers was greater than that for the top 10 swimmers. In general, swimmers who swam 50 m showed a slightly lower transition rate compared with those that swam 100 m. Depending on the age of reference, low-to-moderate correlations were observed between junior and senior peak performances. CONCLUSIONS: Most elite junior athletes did not maintain the elite level in adulthood. Except for athletes in the last year of the junior category (18 years for males and 17 years for females), junior performances were poorly correlated with senior performances.

Eating disorder diagnosis and the female athlete: A longitudinal analysis from college sport to retirement.

OBJECTIVES: Female athletes experience eating disorders (EDs) at clinical, and subclinical, levels; most studies have determined point-prevalence rates through cross-sectional methodologies. To date, few studies have examined the long-term stability of EDs in female athletes; none extend into retirement. DESIGN: A longitudinal investigation of ED classification (i.e., Clinical ED, Subclinical ED, Healthy) and weight control behaviors (e.g., vomiting, laxative use) from when athletes actively competed (T1) into their retirement (T2). METHODS: Participants included U.S. female athletes (N=193) who were collegiate competitors (T1) and eventually were retired from their collegiate sports six years later (T2). RESULTS: At T2, athletes were classified as Healthy (69.9%), Subclinical ED (26.9%), and Clinical ED (3.1%). Overall percentage of Subclinical EDs increased from 18.7% (T1) to 26.9% (T2); 52.8% of T1 Subclinical ED athletes continued to meet criteria for either Subclinical or Clinical ED at T2. Of the 13 Clinical ED athletes at T1, six (46.2%) continued to meet criteria for either a subclinical or clinical ED at T2. Though exercising (2+ hours/day; n=8, 4.1%) and dieting/fasting (4+ times/year; n=14, 7.3%) were the most frequently used weight control behaviors at T2, rates were substantially lower than at T1. CONCLUSIONS: Retirement does not result in immediate remittance of eating concerns among female athletes; many continue or develop Subclinical and Clinical ED symptoms. Thus, addressing healthy body image and nutrition when athletes are competing is imperative to assist prevention and intervention efforts that may alleviate ED symptoms as athletes transition from sport.

A 3-min All-out Upper-body Ergometer Test For Competitive Swimmers.

We examined the application of a land-based swimming ergometer 3-min all-out test to determine physiological predictors of swimming performance. Fourteen young elite swimmers participated (males: n=6; females: n=8). The swimmers completed two 3-min upper-body all-out tests on a swimming ergometer. Additionally, the swimmers completed freestyle swim races ranging from 50 m to 1500 m. High test-retest reproducibility (r=0.98 and coefficient of variation values <7.5%) was evident for ergometer derived peak, mean and critical power. Very strong correlations (r>0.87, p<0.001) were obtained between the 200-, 400-, 800- and 1500-m swimming performances and derived critical speed. Moreover, correlations were found between peak force and peak power and 50-m performance, in addition to critical power and performance for all distances. The critical speed was the dominant predictor of 200- to 1500-m performances (r=0.84-0.99). In conclusion, the land-based 3-min all-out swimming ergometer test is reliable and valid in predicting swimming performance in competitive swimmers and evaluates important physiological components in swimmers independent of technical abilities.

Pacing in World-Class Age Group Swimmers in 100 and 200 m Freestyle, Backstroke, Breaststroke, and Butterfly.

Pacing in swimming has been investigated in pool swimming for elite-standard and age group freestyle swimmers, but little is known about pacing in age group swimmers competing at world class level in backstroke, breaststroke, and butterfly. The aim of this study was to investigate pacing for age group swimmers competing at world class level in 100 and 200 m in the four single disciplines (freestyle, backstroke, breaststroke and butterfly). Data on 18,187 unique finishers competing in four FINA Master World Championships between 2014 and 2019 were analyzed. The sample included 3334 women and 14,853 men. Swimming speed decreased with increasing age (p < 0.05). Freestyle was the fastest and breaststroke the slowest (p < 0.05) stroke. Women and men were faster in 100 m (p < 0.05) than in 200 m. Backstroke was the stroke with the lowest and butterfly with the highest coefficient of variation in swimming speed. One hundred meters had a higher coefficient of variation in swimming speed than breaststroke (p < 0.05). For 100 m, swimming speed decreased for all strokes and all age groups during the second lap. For 200 m, swimming speed was the fastest for all strokes and all age groups during the first lap. In summary, the FINA World Masters Championships presented the unique characteristic that, when all competitors were considered, (i) swimming speed decreased with increasing age, (ii) women and men were faster in 100 m than in 200 m, (iii) freestyle was the fastest stroke and (iv) the largest increase in swimming time for 100 m all strokes and all age groups occurred during the second (out of two) lap and for 200 m, swimming speed was the fastest for all strokes and age groups during the first lap. These findings should help coaches to develop age- and event-tailored pacing strategies.

Testing the application of corrective adjustment procedures for removal of relative age effects in female youth swimming.

The purpose of this study was (1) accurately estimate longitudinal relationships between decimal age (i.e., chronological and relative) and performance in Australian female 100 m (N = 765) and 200 m (N = 428) Breaststroke swimmers (10-18 years); and (2) determine whether corrective adjustment procedures could remove Relative Age Effects (RAEs) in an independent sample of age-matched 100 m (N = 2,491) and 200 m (N = 1,698) state/national level Breaststroke swimmers. In Part 1, growth curve modelling quantified longitudinal relationships between decimal age and swimming performance. In Part 2, relative age distributions (Quartile 1-4) for "All", "Top 25%" and "10%" of swimming times were examined based on raw and correctively adjusted swim times for age-groups. Based on raw swim times, finding identified RAE effect sizes increased in magnitude (small-medium) with selection level ("All"-"Top 25%") in 12-14 years age-groups for both events. However, when correctively adjusted swim performances were examined, RAEs were primarily absent across all age-groups and selection levels. Using longitudinal reference data, corrective adjustment procedures removed relative age advantages in female youth Breaststroke performance. Removing the influence of relative age-related differences is predicted to improve the accuracy of identifying genuinely skilled youth swimmers.

Cardiovascular Disease and Triathlon-Related Deaths in the United Kingdom.

INTRODUCTION: Triathlon is one of the fastest growing sports in the United Kingdom. However, in recent years several deaths have occurred. The intention of this study is to identify these cases and examine the role cardiovascular disease played in these deaths. METHODS: An extensive online search was performed to identify triathlon-related deaths (TRDs) in the United Kingdom and UK citizens who died during or as a result of competing in triathlons abroad. British Triathlon provided the number of participants who took part in UK-based events. Coroners provided information on all those who died. RESULTS: Between 2009 and 2015, 991,186 participants took part in British Triathlon-sanctioned events. Five TRDs in the United Kingdom were identified. The mortality rate was 0.5 per 100,000 participants. Deaths occurred during or after the swim (3), cycle (1), and run (1) events. During the same period, 5 TRDs were identified among UK citizens competing abroad. These deaths occurred during or after the swim (2), cycle (1), and run (2) events. Cardiovascular pathology was cited as a cause or contributing factor in half of the fatalities. Four deaths were referred to a specialist cardiac pathology service for autopsy. CONCLUSIONS: Cardiovascular disease was found to be the most common cause of TRD. Further research is needed to determine the underlying cardiac pathology that triggers TRDs. With this information it may be possible to develop screening tools that can prevent similar fatalities from occurring in the future.

Identifying a gap in drowning prevention: high-risk populations.

INTRODUCTION: Some populations have been less susceptible to reductions in drowning than others. It has been hypothesised that this is due to prevention strategies failing to account for the influence of social determinants (such as ethnicity, socioeconomic status). Populations such as ethnic minorities have been over-represented in injury statistics, however this is not well explored in drowning. This study aims to identify high-risk populations for drowning, risk factors and prevention strategies. METHODS: A literature review undertaken systematically using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses approach was conducted of peer-reviewed literature in English, published between 1990 and 2018 from high-income countries. Search terms included drowning, water safety, ethnic minority, migrant, and culturally diverse. RESULTS: In total, 35 articles were included. High-risk populations identified were: ethnic minorities, First Nations/Aboriginal people, migrants and rural residents. Over half (51%) focused on children (0-18 years). Risk factors included social determinants, swimming ability and knowledge, attitudes and behaviour. Four intervention studies were found; two focused on upskilling adults from high-risk populations to increase employment opportunities within the aquatic industry; an evaluation of a 10-year rock fishing safety education project and a learn-to-swim programme for minority children. Proposed prevention strategies included education, practical skills, research, policy and engagement. DISCUSSION: Limited literature exists pertaining to drowning among adults from high-risk populations. There is a need to increase the sophistication of drowning prevention strategies addressing the disparities in drowning from a culturally appropriate perspective. Acknowledging the role of the social determinants of health in drowning prevention is essential in order to improve drowning outcomes for high-risk populations globally.

Developing drowning prevention strategies for rivers through the use of a modified Delphi process.

INTRODUCTION: Internationally, rivers are a leading drowning location, yet little evidence exists evaluating river drowning prevention strategies. This study aims to use expert opinion to identify strategies more likely to be effective. METHODS: Using a modified Delphi process, a virtual panel of 30 experts from 12 countries considered, grouped and prioritised strategies for river drowning prevention. Proposed strategies were assessed against known evidence and suitability in high-income countries (HICs) as well as low-income and middle-income countries (LMICs) using expert opinion. The final phase consolidated a list of strategies whose effectiveness was assessed against 10 evidence-based river drowning scenarios. RESULTS: An initial list of 424 prevention strategies was refined to 22. After being assessed against the 10 scenarios, a final list of 13 strategies was derived. Strategies addressed alcohol consumption around rivers, flood mitigation, improving child supervision, learning to swim, increased lifejacket wear and achieving community-wide resuscitation skills. DISCUSSION: While all 13 strategies were assessed as being effective in both LMICs and HICs by at least 60% of the respondents, further work is required to define river drowning at a country level and therefore allow for effective solutions to be developed, particularly in LMICs. No strategy will be effective in isolation and must be implemented alongside policy and behaviour change, public awareness and education. Evaluation should be incorporated as part of any future implementation of strategies. CONCLUSION: This Delphi process identified 13 drowning prevention strategies for rivers. Further research is required to validate the efficacy of these findings through implementation and evaluation.

An enjoyable school-based swimming training programme improves students' aquaticity.

AIM: The main objectives of this research were to a) examine the test-retest reliability of aquaticity test (study 1), b) investigate the efficacy of 'swimming lesson', during the physical education course, in the aquaticity (study 2) and c) examine enjoyment from the 'swimming lesson' (study 3) in primary school students of the 3rd grade. METHODS: In the first study, 23 students performed 2 assessment sessions for the evaluation of aquaticity, separated by 1 week. In the second study, 30 students followed a short-term swimming training programme (9 sessions). Before and after the programme, students' aquaticity was assessed. In the third study, enjoyment was examined in 273 students who followed the short-term swimming programme. RESULTS: The test-retest reliability for the assessment of students' aquaticity was high (ICC = 0.87-0.99). Paired t tests, also, revealed significant improvement (28-62.7%) in the aquaticity of the children following the swimming programme. A great percentage of students reported high levels of enjoyment (92.2%). CONCLUSION: A short-term swimming programme, incorporated into the physical education course, is an enjoyable exercise modality that may be used for the improvement of children's aquaticity. We, also, found that the testing protocol may be reliably used for the evaluation of aquaticity in the paediatric population.

Pacing Profiles and Competitive Performance of Elite Female 400-m Freestyle Swimmers.

Lipinska, P, and Hopkins, WG. Pacing profiles and competitive performance of elite female 400-m freestyle swimmers. J Strength Cond Res 34(1): 218-224, 2020-Pacing can impact competitive endurance performance. The objective of this study was to determine relationships between pacing parameters and competitive performance of elite female 400-m freestyle swimmers. Publicly available websites provided 50-m split and final times for 381 swims of 20 elite female swimmers in over 150 national and international competitions between 2004 and 2016. Most pacing profiles displayed negative quadratic curvature, with the fifth of the 8 laps being the median slowest. The mean times for the first and last laps were faster than predicted by the quadratic by 5.6 and 1.9%, respectively, and lap-to-lap variability was 0.65%. Scatter plots of each swimmer's final time often showed no obvious relationships with their pacing parameters, suggesting that swimmers compensated for changes in one parameter with changes in another. However, some plots showed a U shape or linear trend that allowed tentative identification of optimum values of the pacing parameters. In these plots, it was apparent that about half the swimmers might make small to moderate improvements (up to ∼1%) by changing the slope or curvature of their pacing profile or by changing time in the first or last laps. This approach for characterizing pacing profiles to identify possible improvements might be appropriate to assess pacing in other sports with multiple laps, frequent competitions, and relatively constant environmental conditions.

Toward Prevention of Doping in Youth Sport: Cross-Sectional Analysis of Correlates of Doping Tendency in Swimming.

Doping is recognized as one of the most important problems in sports, but a limited number of studies have investigated doping problems in youth athletes. This study aimed to evaluate doping tendency (potential doping behavior (PDB)) and correlates of PDB in youth age swimmers. The participants were 241 competitive swimmers (131 females; 15.3 ± 1.1 years of age, all under 18 years old). Variables included predictors and PDB (criterion). Predictors consisted of sociodemographic factors (gender and age), sport-related variables (i.e., experience in swimming and sport achievement), variables explaining coaching strategy and training methodology, consumption of dietary supplements (DS), knowledge about doping, and knowledge about sports nutrition and DS (KSN). In addition to the descriptive statistics and differences between genders, a multinomial regression using PDB as the criterion (negative-, neutral-, or positive-PDB, with a negative-PDB as the reference value) was calculated to define associations between predictors and criterion. With only 71% of swimmers who declared negative-PDB results indicated an alarming figure. Boys with better KSN were more negatively oriented toward positive-PDB (OR: 0.77, 95%CI: 0.60-0.95). In girls, lower competitive achievement was evidenced as a risk factor for neutral-PDB (OR: 0.39, 95%CI: 0.24-0.63). Also, higher neutral-PDB (OR: 0.88, 95%CI: 0.81-0.96) and positive-PDB (OR: 0.90, 95%CI: 0.83-0.99) were identified in girls who began with intensive training in younger age. Because of the alarming figures of PDB, there is an evident need for the development of systematic antidoping educational programs in youth swimming. In doing so, focus should be placed on girls who began intensive training at an earlier age and those who did not achieve high competitive results.

Drowning among fishing communities on the Tanzanian shore of lake Victoria: a mixed-methods study to examine incidence, risk factors and socioeconomic impact.

OBJECTIVES: To estimate the incidence of unintentional fatal drowning and describe associated risk factors among Lake Victoria fishing communities, and to assess perceived social, financial and other impacts among families and colleagues of persons who drowned. DESIGN: A retrospective, observational mixed-methods study, conducted between September 2017 and February 2018. SETTING: Eight Tanzanian fishing communities on Lake Victoria. PARTICIPANTS: Persons who drowned in the preceding 24 months were identified using an extensive community networking approach. Adult family members, colleagues or community members familiar with the habits and behaviours of people who drowned and/or circumstances of drowning incidents participated in surveys (n=44) and in-depth interviews (n=22). MAIN OUTCOME MEASURES: Pooled drowning incidence, with sensitivity analyses allowing for uncertainties in population estimates. Risk factors were identified through the evaluation of behavioural characteristics of persons who drowned and circumstances of drowning incidents. Perceived socioeconomic impacts were assessed through semi-structured interviews with their family members and colleagues. RESULTS: The estimated drowning incidence was 217/100 000 person-years (95% CI 118 to 425/100 000). Of 86 victims identified, 70 (81%) were fishermen (79% aged 18-40 years; all men) and 9 were children (all ≤10 years). All deaths occurred in the lake. Most adults (65/77; 84%) were fishing from a boat when they drowned; 57/77 (74%) died in the evening (from ~5 pm) or at night. Six children (67%) drowned while swimming/playing at the lakeshore unsupervised. Few victims (2/86; 2%) were wearing a life jacket at the time of death. Reported socioeconomic impacts of these deaths ranged from income loss to family break-up. CONCLUSIONS: Drowning is a significant risk in Tanzanian lakeside fishing communities, with estimated mortality exceeding national incidence rates of fatal malaria, tuberculosis or HIV, but preventative strategies appear uncommon. Socioeconomic impact at the family level may be substantial. Intervention strategies are required to reduce the drowning burden among this neglected at-risk population.

Automatic Identification of Physical Activity Type and Duration by Wearable Activity Trackers: A Validation Study.

BACKGROUND: Activity trackers are now ubiquitous in certain populations, with potential applications for health promotion and monitoring and chronic disease management. Understanding the accuracy of this technology is critical to the appropriate and productive use of wearables in health research. Although other peer-reviewed validations have examined other features (eg, steps and heart rate), no published studies to date have addressed the accuracy of automatic activity type detection and duration accuracy in wearable trackers. OBJECTIVE: The aim of this study was to examine the ability of 4 commercially available wearable activity trackers (Fitbits Flex 2, Fitbit Alta HR, Fitbit Charge 2, and Garmin Vívosmart HR), in a controlled setting, to correctly and automatically identify the type and duration of the physical activity being performed. METHODS: A total of 8 activity types, including walking and running (on both a treadmill and outdoors), a run embedded in walking bouts, elliptical use, outdoor biking, and pool lap swimming, were tested by 28 to 34 healthy adult participants (69 total participants who participated in some to all activity types). Actual activity type and duration were recorded by study personnel and compared with tracker data using descriptive statistics and mean absolute percent error (MAPE). RESULTS: The proportion of trials in which the activity type was correctly identified was 93% to 97% (depending on the tracker) for treadmill walking, 93% to 100% for treadmill running, 36% to 62% for treadmill running when preceded and followed by a walk, 97% to 100% for outdoor walking, 100% for outdoor running, 3% to 97% for using an elliptical, 44% to 97% for biking, and 87.5% for swimming. When activities were correctly identified, the MAPE of the detected duration versus the actual activity duration was between 7% and 7.9% for treadmill walking, 8.7% and 144.8% for treadmill running, 23.6% and 28.9% for treadmill running when preceded and followed by a walk, 4.9% and 11.8% for outdoor walking, 5.6% and 9.6% for outdoor running, 9.7% and 13% for using an elliptical, 9.5% and 17.7% for biking, and was 26.9% for swimming. CONCLUSIONS: In a controlled setting, wearable activity trackers provide accurate recognition of the type of some common physical activities, especially outdoor walking and running and walking on a treadmill. The accuracy of measurement of activity duration varied considerably by activity type and tracker model and was poor for complex sets of activity, such as a run embedded within 2 walking segments.

Association of the 25(OH) vitamin D status with upper respiratory tract infections morbidity in water sports elite athletes.

BACKGROUND: The aim of this study is to determine seasonal changes of total serum 25(OH) vitamin D (VD) concentration and its influence on upper respiratory tract infection (URTI) morbidity among water sports elite athletes. METHODS: The study was planned as a prospective, non-interventional, observational study. Study participants included 40 elite athletes and 30 control individuals. Serum levels of 25(OH) VD and TNF-α, IFN-γ, IL-4 and IL-6 were detected by ELISA technique. Frequency of acute URTI in participants was determined by medical cards and self-reported questionnaire during the year. RESULTS: VD deficiency/insufficiency dominated in both groups of elite athletes, especially in synchronized swimmers (100%) in comparison with the control individuals (63.3%) (P≤0.05). Prevalence of VD deficiency/insufficiency depends on the season, but independently on the season the highest values were observed among athletes. VD sufficiency was detected in 30% and 13.3% of the control individuals in August and February and only in 10% of swimmers in August. More than 3 episodes of URTI were detected only in elite athletes in winter-spring. The elevation of TNF-α, IL-4, IL-6 and decrease of IFN-γ levels were detected in all athletes, but they were more expressed in swimmers. CONCLUSIONS: VD insufficiency is quite pronounced among elite athletes engaged in synchronized swimming and swimmers. It is accompanied with a decrease of IFN-γ, increase of TNF-α, IL-4 and IL-6 level, and elevation of URTI morbidity. Seasonal monitoring and correction of the VD level for normalization of cytokine profile and decrease of URTI morbidity is definitely advised.