Analysis of pacing and kinematics in 3000 m freestyle in elite level swimmers

This study aimed to determine elite swimmers' pacing strategy in the 3000 m event and to analyse the associated performance variability and pacing factors. Forty-seven races were performed by 17 male and 13 female elite swimmers in a 25 m pool (20.7 ± 2.9 years; 807 ± 54 FINA points). Lap performance, clean swim velocity (CSV), water break time (WBT), water break distance (WBD), stroke rate (SR), stroke length (SL) and stroke index (SI) were analysed including and excluding the first (0-50 m) and last lap (2950-3000 m). The most common pacing strategy adopted was parabolic. Lap performance and CSV were faster in the first half of the race compared to the second half (p < 0.001). WBT, WBD, SL and SI were reduced (p < 0.05) in the second half compared to the first half of the 3000 m when including and excluding the first and last laps for both sexes. SR increased in the second half of the men's race when the first and last laps were excluded. All studied variables showed significant variation between the two halves of the 3000 m, the highest variation being obtained in WBT and WBD, suggesting that fatigue negatively affected swimming kinematics.

Hydration and water intake practices of commercial long-distance drivers in Ghana: what do they know and why does it matter?

BACKGROUND

The World Health Organization indicates that hydration is indispensable to human life. A long-period of dehydration can result in fatigue, drowsiness and mental confusion which can result in committing serious blunders. For commercial drivers, however, these blunders can be life-threatening and their hydration cannot be overemphasized.

AIM

This study was therefore undertaken to assess the water intake practices of Commercial Long-Distance drivers (CLDDs). The study was also aimed at assessing their knowledge levels on the role of water in promoting a healthy body and the consequences of dehydration.

SETTING

CLDDs in Ghana who ply between Accra - Cape Coast - Takoradi or Accra - Kumasi.

METHODS

A cross-sectional study which involved 256 CLDDs was conducted at six (6) commercial bus stations in Accra and Cape Coast from December 2019 to January 2020. Structured questionnaires were administered to obtain socio-demographic and water intake practices of CLDDs. SPSS was used to generate descriptive statistics based on the data collected.

RESULTS

A high proportion (57.8%) of the CLDDs reported that they drunk about 2500ml-3000ml of water on a daily basis. Most (53.1%) relied on their thirst feeling to prompt them to drink water. A little over half (51.1%) consumed energy drinks believed to hydrate the body. A major barrier to drinking water regularly was to avoid frequent stop-overs to use the washroom while travelling.

CONCLUSION

The findings reveal concerns about knowledge gaps with regard to the importance of water consumption and barriers to adequate drinking of water among CLDDs. Findings also suggest that many CLDDs relied on their thirst perceptions to prompt them to drink water. Health Education programmes targeting CLDDs should include conveying the importance of water intake and healthy hydration practices for optimal physical and cognitive performance.

Long-distance longitudinal prostate MRI quality assurance: from startup to 12 months

PURPOSE

To evaluate a 12-month long-distance prostate MRI quality assurance (QA) program.

METHODS

The need for IRB approval was waived for this prospective longitudinal QA effort. One academic institution experienced with prostate MRI [~ 1000 examinations/year (Site 2)] partnered with a private institution 240 miles away that was starting a new prostate MRI program (Site 1). Site 1 performed all examinations (N = 249). Four radiologists at Site 1 created finalized reports, then sent images and reports to Site 2 for review on a rolling basis. One radiologist at Site 2 reviewed findings and exam quality and discussed results by phone (~ 2-10 minutes/MRI). In months 1-6 all examinations were reviewed. In months 7-12 only PI-RADS ≤ 2 and 'difficult' cases were reviewed. Repeatability was assessed with intra-class correlation (ICC). 'Clinically significant cancer' was Gleason ≥ 7.

RESULTS

Image quality significantly (p < 0.001) improved after the first three months. Inter-rater agreement also improved in months 3-4 [ICC: 0.849 (95% CI 0.744-0.913)] and 5-6 [ICC: 0.768 (95% CI 0.619-0.864)] compared to months 1-2 [ICC: 0.621 (95% CI 0.436-0.756)]. PI-RADS ≤ 2 examinations were reclassified PI-RADS ≥ 3 in 19% (30/162); of these, 23 had post-MRI histology and 57% (13/23) had clinically significant cancer (5.2% of 249). False-negative examinations [N = 18 (PI-RADS ≤ 2 and Gleason ≥ 7)] were more common at Site 1 during months 1-6 [9% (14/160) vs. 4% (4/89)]. Positive predictive values for PI-RADS ≥ 3 were similar.

CONCLUSION

Remote quality assurance of prostate MRI is feasible and useful, enabling new programs to gain durable skills with minimal risk to patients.

Male and female Ethiopian and Kenyan runners are the fastest and the youngest in both half and full marathon

In major marathon races such as the 'World Marathon Majors', female and male East African runners particularly from Ethiopia and Kenya are the fastest. However, whether this trend appears for female and male Ethiopians and Kenyans at recreational level runners (i.e. races at national level) and in shorter road races (e.g. in half-marathon races) has not been studied yet. Thus, the aim of the present study was to examine differences in the performance and the age of female and male runners from East Africa (i.e. Ethiopians and Kenyans) between half- and full marathons. Data from 508,108 athletes (125,894 female and 328,430 male half-marathoners and 10,205 female and 43,489 male marathoners) originating from 126 countries and competing between 1999 and 2014 in all road-based half-marathons and marathons held in one country (Switzerland) were analysed using Chi square (χ(2)) tests, mixed-effects regression analyses and one-way analyses of variance. In half-marathons, 48 women (0.038 %) and 63 men (0.019 %) were from Ethiopia and 80 women (0.063 %) and 134 men (0.040 %) from Kenya. In marathons, three women (0.029 %) and 15 men (0.034 %) were from Ethiopia and two women (0.019 %) and 33 men (0.075 %) from Kenya. There was no statistically significant association between the nationality of East Africans and the format of a race. In both women and men, the fastest race times in half-marathons and marathons were achieved by East African runners (p < 0.001). Ethiopian and Kenyan runners were the youngest in both sexes and formats of race (p < 0.001). In summary, women and men from Ethiopia and Kenya, despite they accounted for <0.1 % in half-marathons and marathons, achieved the fastest race times and were the youngest in both half-marathons and marathons. These findings confirmed in the case of half-marathon the trend previously observed in marathon races for a better performance and a younger age in East African runners from Ethiopia and Kenya.

Do non-elite older runners slow down more than younger runners in a 100 km ultra-marathon?

Background

This study investigated changes in normalised running speed as a proxy for effort distribution over segments in male elite and age group 100 km ultra-marathoners with the assumption that older runners would slow down more than younger runners.

Methods

The annual ten fastest finishers (i.e. elite and age group runners) competing between 2000 and 2009 in the ‘100 km Lauf Biel’ were identified. Normalised average running speed (i.e. relative to segment 1 of the race corrected for gradient) was analysed as a proxy for pacing in elite and age group finishers. For each year, the ratio of the running speed from the final to the first segment for each age cohort was determined. These ratios were combined across years with the assumption that there were no ‘extreme’ wind events etc. which may have impacted the final relative to the first segment across years. The ratios between the age cohorts were compared using one-way ANOVA and Tukey’s post-hoc test. The ratios between elite and age group runners were investigated using one-way ANOVA with Dunnett’s multiple comparison post-hoc tests. The trend across age groups was investigated using simple regression analysis with age as the dependent variable.

Results

Normalised average running speed was different between age group 18–24 years and age groups 25–29, 30–34, 35–39, 40–44, 45–49, 50–54, 55–59 and 65–69 years. Regression analysis showed no trend across age groups (r² = 0.003, p > 0.05).

Conclusion

To summarize, (i) athletes in age group 18–24 years were slower than athletes in most other age groups and (ii) there was no trend of slowing down for older athletes.