Possible effects of uberization on the quality of sleep of professional drivers.

Uber and other on-demand business platforms drivers experience unparalleled flexibility in work hours, and many are using this model instead of working a fixed-hours job. The option of working more hours a day and, as a result, increasing the remuneration received is often chosen by drivers even at the expense of sleep. Due to their professional obligation, this population is at risk of excessive sleepiness due to sleep deprivation or poor sleep quality, increasing the risk of detrimental effects on health and the risk of car accidents. Considering that sleep is essential for general health, it is mandatory to create strategies to address these issues, such as limiting the maximum number of hours worked a day under the laws regulating labor rights and periodically assessing drivers' alertness.

Pacing strategy of a wheelchair athlete in a 5x and 10x Ironman ultra triathlon: a case study.

OBJECTIVE: For disabled athletes such as wheelchair athletes, there is no knowledge about competing and pacing during a long-distance triathlon such as an Ironman triathlon. This study aimed to investigate the pacing strategy of a paraplegic wheelchair athlete competing and finishing a Quintuple Iron ultra-triathlon (i.e., five times 3.8 km swimming, 180 km handbike cycling and 42.195 km wheelchair racing in five days) and a Deca Iron ultra-triathlon (10 times the same distance in 10 days). METHODS: Data from an ultra-distance triathlon race (Swissultra) covering 5x and 10x Ironman distance were collected. Official performance data were acquired from the race organizer's website and athlete's personal information from the athlete through online interviews. The athlete is a man born in 1962, the races analysed in this study were held in the summer of 2017 (5x) and 2019 (10x). The split times for swimming, cycling and running, the overall race times for each Ironman and the lap times in cycling (handbike) and running (wheelchair) were analysed. RESULTS: The athlete finished the Quintuple Iron ultra-triathlon in an overall race time of 66:28:31 h:min:s and the Deca Iron ultra-triathlon in 137:03:20 h:min:s. He adopted an even pacing in both races in split disciplines and for overall race time. CONCLUSION: The paraplegic wheelchair athlete was able to finish both a Quintuple and a Deca Iron ultra-triathlon by adopting an even pacing in all split disciplines and for overall race time.IMPLICATIONS FOR REHABILITATIONTriathlon is a growing sport among athletes with spinal cord injury.Ultra-triathlons are ultra-endurance events and pacing is a key aspect to a successful race regardless the athlete's category.An athlete with a spinal cord injury finished a 5x and 10x Ironman ultra-triathlon applying an even pacing strategy.

Cycle ergometer training and resistance training similarly increase muscle strength in trained men.

The aim of this study was to compare two different maximal intensity exercise modality training protocols of similar durations on muscle strength, cardiorespiratory fitness, and lower limb composition in recreationally trained men. Twenty-five trained men (28.9 ± 5.6 years) were randomly divided into Cycle ergometer (4 sets of 30 seconds sprints) and Leg press (4 sets of 10-12 repetitions to momentary failure). Both groups trained three times a week for 5 weeks. Before and after the training period, the participants performed a 10-repetition maximum (10RM) test for knee extension, an incremental exercise test on a treadmill for time to exhaustion (TTE) and peak oxygen consumption (V˙O2peak) and underwent dual energy X-ray absorptiometry to assess lower limb composition. Knee extension 10RM and TTE increased in both groups with no statistically significant between group (p = 0.614 and p = 0.210). Only cycle ergometer group increased V˙O2peak (p = 0,012). For all lower limb composition outcomes, changes were minimal. The results suggest that 5 weeks of effort and duration matched exercise protocols using cycle ergometer training or leg press may produce similar strength adaptations.

Age-related differences in torque in angle-specific and peak torque hamstring to quadriceps ratios in female soccer players from 11 to 18 years old: Α Cross-sectional study.

The aim of this study was to evaluate and compare the hamstring (H) and quadriceps (Q) strength, bilateral difference and balance ratios in female soccer players. Ninety-three athletes from three age groups: under 13 (U13), 15 (U15) and 18 (U18) participated in the study performing isokinetic tests to measure peak torque, total work, average power and torque at 30º of thigh muscles. Conventional strength balance ratios, angle-specific balance ratio and bilateral strength difference were evaluated. There was bilateral strength difference for extensor muscles total work (p = 0.02) in U13 and flexor muscles peak torque (p = 0.02) in U15. All variables were superior in U15 than U13 (p <.05). There was no strength difference between U15 and U18. Balance ratios did not differ between sides or age groups. The study showed that although peak torque values were higher in U15 than in U13, balance ratios were similar.

Knee isokinetic muscle strength and balance ratio in female soccer players of different age groups: a cross-sectional study.

Background: As a consequence of years of soccer training and sexual maturation, there is an increase in lower body muscle mass and strength especially in the knee extensors and flexors muscles. In this context, the lack of knee joint stability, resulting from strength imbalance between knee extensor and flexors muscles, has been associated with knee injuries. The aim of this study was to compare the knee flexor and extensor muscle peak torque, average power, contralateral deficit, conventional and functional balance ratios of female soccer players from different age groups.Methods: Sixty-six female soccer players were divided into four groups: under 13 (U13), under 15 (U15), under 17 (U17) years old and professional (PRO). Flexor and extensor knee muscle strength in concentric and eccentric actions of both limbs were assessed using isokinetic dynamometer.Results: For the dominant limb, the knee concentric extensor muscles peak torques, assessed at 60 and at 240 deg/sec, and the average power of U15 group were significantly higher than U13 group. Extensor muscle average power of the PRO group was higher than U17. Dominant knee flexor average power of U15 was significantly higher than the U13 group. Peak torque at 60 deg/sec and 240 deg/sec and average power of the PRO group were higher than the U17 group. No differences were found regarding the eccentric action for flexor and extensor muscles. Conventional and functional balance ratios were similar among all age group, except for U13, which presented higher values than the U15 group for the dominant limb.Conclusions: The greatest improvement in muscular performance occur when the athlete starts practicing soccer (after U13) and when they become professional (after U17) and the balance ratios, and muscle balance ratios remain stable in all age groups, although they are below the recommended level in the literature, which may increase the risk for lower limb injury.

Frequency and associated factors of poor knee alignment in young Brazilian volleyball players.

Objectives: Poor knee alignment during the deceleration phase of closed kinetic chain movements, such as landings, is a relevant risk factor for injuries in sports. This study assessed the knee alignment and possible associated factors in young Brazilian volleyball athletes Methods: One hundred and seventeen athletes of both genders (9-19 years old) were assessed during a drop jump for the observation of knee alignment. Chi-square test was used to describe the association between poor knee alignment and: gender, age category (≤14 years and ≥15 years), sports experience, participation in competitions, the presence of knee pain during training, and history of lower limb injury Results: Seventy percent of athletes presented poor knee alignment, which was slightly associated with a sports experience lower than one year. Conclusion: Thus, considering the high number of volleyball practitioners and its strong presence in physical education classes, preventive measures should be adopted for young volleyball athletes of both genders, especially in the sports initiation phase.

Profiling the Use of Dietary Supplements by Brazilian Physical Education Professionals.

A survey was designed to examine the use of dietary supplements by Brazilian physical education professionals. The study included 131 Brazilian physical education professionals (83 men and 48 women). A descriptive statistical analysis was performed (mean, standard deviation, and absolute and relative frequencies). A chi-square test was applied to evaluate differences in use of dietary supplements according to particular variables of interest (p < .05). Forty-nine percent of respondents used dietary supplements. Approximately 59% of dietary supplement users took two or more kinds of supplements. Among users of supplements, men professionals (73%) consumed more dietary supplements than women (27%). The most-consumed dietary supplement was whey protein (80%). The results showed a higher use of dietary supplements by men. The most-consumed supplements were rich in protein. The consumption of dietary supplements by almost half of the participants in this study suggests that participants did not consider their dietary needs to be met by normal diet alone.