Bone Mineral Density in Mountain, Road Cyclists and Untrained Controls: Exercise, Diet and Hormones

Purpose: The aim of the study was to compare bone mineral density (BMD) in the lumbar spine (LSBMD) and the femoral neck (FBMD) in male road cyclists (RC n = 39), mountain cyclists (MC n = 30) and controls (C n = 27) and to determine the factors associated with BMD in the same group of participants. Methods: BMD, fat mass (FM) and fat-free mass (FFM) were measured using DXA. Calcium intake (Cal), exercise energy expenditure (EEE) and energy availability (EA) were assessed using self-reported questionnaires. Samples for circulating hormones were also obtained. VO2max was estimated by a cycloergometric test. Results: After adjustment for body mass, in cyclists LSBMD (RC 0.98 ± 0.12; MC 0.98 ± 0.10 g/cm2) was significantly lower than in C (1.11 ± 0.10; p < .001), while FBMD resulted in no significant difference in cyclists compared to C (p = 0.213). EA (kcal/FFM/day) was different in cyclists and in C (p < .05). In C, EEE and EA were positively associated with LSBMD (R = 0.561, R = 0.656, respectively, p < .01), whereas only EA was associated with FBMD (R = 0.554, p < .05); a positive association between EA and FBMD was found in MC (R = 0.464, p < .05). A negative relationship between VO2max and LSBMD in RC (R = -0.418, p < .05) and a positive one between EEE and LSBMD in MC were found (R = 0.605, p < .001). CaI, free testosterone and cortisol were unrelated to BMD. Conclusion: Both the RC and MC had lower LSBMD than C, whereas no difference was found between the two groups of cyclists. The factors associated with BMD are manifold, vary in relation to the measurement site and are likely different in RC, MC and C.

Mortality due to traffic accidents in Colombia: Profiles of pedestrians and cyclists, 1998-2019

Background: Traffic accidents are an important issue for public health and a threat for sustainable development, with pedestrians and cyclists having been recognized as the most vulnerable actors on the streets. The objective of this study was to analyze the profiles of pedestrians and cyclists who died as a result of traffic accidents in Colombia during the 1998-2019 period. Methods: An observational and descriptive study, with the deaths due to traffic accidents in Colombia between 1998 and 2019 as data source. Secondary data were taken from the Vital statistics of Colombia (EEVV), published by Departamento Administrativo Nacional de Estadística (DANE). A trend analysis of the number of deaths during the period under study was performed, and such number was examined against sex to identify potential differences. Multiple correspondence analysis was employed to elaborate the profile of pedestrians and cyclists who die due to traffic accidents. Three profiles were prepared for each road actor: a global profile, one for 1998, and another for 2019. Results: The mortality profiles are different for pedestrians and cyclists, and, in turn, there are also demographic, geographic, and socioeconomic conditions in each type of road actor, which determine higher mortality risks. High population density, younger age group in the cyclists and adults among the pedestrians, low schooling levels and absence of health insurance are suggested as key factors in these profiles. Related to sex, for men is not possible to establish a profile. Women's cases are commonly related to health insurance, age, and population density. Conclusions: Several contextual and demographic characteristics in pedestrians and cyclists allow delimiting mortality profiles. The profiles that were identified suggest the need to articulate road safety policies with other social and development policies in order to coordinate and integrate intersectoral actions that reduce mortality in these road actors.

Effect of Pulsed Electromagnetic Fields (PEMFs) on Muscular Activation during Cycling: A Single-Blind Controlled Pilot Study

PURPOSE

PEMF stimulation results in a higher O₂ muscle supply during exercise through increased O₂ release and uptake. Given the importance of oxygen uptake in sport activity, especially in aerobic disciplines such as cycling, we sought to investigate the influence of PEMF on muscle activity when subjects cycled at an intensity between low and severe.

METHODS

Twenty semi-professional cyclists performed a constant-load exercise with randomized active (ON) or inactive (OFF) PEMF stimulation. Each subject started the recording session with 1 min of cycling without load (warm-up), followed by an instantaneous increase in power, as the individualized workload (constant-load physical effort). PEMF loops were applied on the vastus medialis and biceps femoris of the right leg. We recorded the electromyographic activity from each muscle and measured blood lactate prior the exercise and during the constant-load physical effort.

RESULTS

PEMF stimulation caused a significant increase in muscle activity in the warm-up condition when subjects cycled without load (p < 0.001). The blood lactate concentration was higher during PEMF stimulation (p < 0.001), a possible consequence of PEMF's influence on glycolytic metabolism.

CONCLUSION

PEMF stimulation augmented the activity and the metabolism of muscular fibers during the execution of physical exercise. PEMF stimulation could be used to raise the amplitude of muscular responses to physical activity, especially during low-intensity exercise.

Cyclist Orientation Estimation Using LiDAR Data

It is crucial for an autonomous vehicle to predict cyclist behavior before decision-making. When a cyclist is on real traffic roads, his or her body orientation indicates the current moving directions, and his or her head orientation indicates his or her intention for checking the road situation before making next movement. Therefore, estimating the orientation of cyclist's body and head is an important factor of cyclist behavior prediction for autonomous driving. This research proposes to estimate cyclist orientation including both body and head orientation using deep neural network with the data from Light Detection and Ranging (LiDAR) sensor. In this research, two different methods are proposed for cyclist orientation estimation. The first method uses 2D images to represent the reflectivity, ambient and range information collected by LiDAR sensor. At the same time, the second method uses 3D point cloud data to represent the information collected from LiDAR sensor. The two proposed methods adopt a model ResNet50, which is a 50-layer convolutional neural network, for orientation classification. Hence, the performances of two methods are compared to achieve the most effective usage of LiDAR sensor data in cyclist orientation estimation. This research developed a cyclist dataset, which includes multiple cyclists with different body and head orientations. The experimental results showed that a model that uses 3D point cloud data has better performance for cyclist orientation estimation compared to the model that uses 2D images. Moreover, in the 3D point cloud data-based method, using reflectivity information has a more accurate estimation result than using ambient information.

The Influence of Gender on Food Consumption Patterns Among National-Level Adolescent Cyclists

Background and objective Adolescents in general make poor food choices due to a lack of awareness, social pressure, and other factors, leading to a faulty lifestyle. On the other hand, the adolescent athletic population is associated with a healthy eating pattern. In light of this, this study aimed to evaluate the eating behavior of adolescent cyclists competing at the national level. Methods A total of 50 national-level adolescent cyclists (26 males and 24 females) were assessed for eating behavior, daily food consumption patterns, and eating habits around exercise time by using a pre-tested validated questionnaire, Food Frequency Questionnaire (FFQ), and 24-hour Food Recall. Results The majority (82%) of the cyclists were non-vegetarians, followed by lacto-vegetarians (14%) and lacto-ovo vegetarians (14%). Of note, 72% of the cyclists consumed four meals consisting of breakfast, lunch, snacks, and dinner daily, while 28% skipped at least one of the meals. The preference for takeaways (52%) surpassed dine-outs (34%) and home-cooked (14%) food. Pre-training snack was consumed by 37% and post-training snack by 47%. Cyclists daily consumed breakfast cereals (76%), bread (94%), pulses (92%), fruits (100%), vegetables (62%), milk (84%), milk products (90%), egg (82%), poultry, fish, and meat (74%), dry fruits, nuts, and seeds (78%), and saturated fats (100%). Junk foods (94%) and sweetened beverages (70%) were consumed at least once a week. No significant difference was observed in eating behavior and daily food consumption pattern between male and female cyclists. Conclusion The eating behavior of adolescent cyclists was inclined towards the consumption of saturated fats, junk food, and sweetened beverages. Male and female athletes have similar food habits. There is a need for the implementation of behavior change-oriented nutrition strategies to inculcate healthy eating habits among adolescent cyclists.

[Pro-health cycle lane versus environmental pollution and trauma]

A bicycle as a mean of transport and recreation, but is it a healthy lifestyle? The construction of numerous cycle lanes in cities and promotion of physical activity aims to encourage the public to move around by bicycle. The aim of mass cycling is to reduce car exhaust emissions and, on the other hand, to improve public health. The paper presents the potential benefits of cycling, but also its negative effects on the human body. Minimizing the danger of using a bicycle lies not only with cyclists, but also with people who are planning to build cycle lane.

Liquid chromatography-tandem mass spectrometry and confirmation by liquid chromatography-high-resolution mass spectrometry hair tests to evidence use of tizanidine by racing cyclists

Tizanidine, an imidazoline derivative close to clonidine, is a central alpha-2 adrenergic receptor agonist. Therapeutically, the drug is used as a muscle relaxant under the trade names Sirdalud™ or Zanaflex™. The drug is not prohibited by the World Anti-Doping Agency but, for therapeutic purposes, can only be obtained via a nominative temporary use authorization. The French public health police requested the laboratory to test for tizanidine in head hair specimens collected from international racing cyclists. Using Liquid chromatography-tandem mass spectrometry (LC/MS-MS) and confirmation by liquid chromatography-high-resolution mass spectrometry (LC/HRMS), after pH 9.5 borate buffer overnight incubation of 20 mg and subsequent solvents extraction, tizanidine was identified in the hair of three athletes at 1.1, 3.7, and 11.1 pg/mg. This is the first evidence that tizanidine is incorporated in human hair. However, it was not possible to interpret the data in terms of doses and frequency of use due to a lack of controlled study.

Hip pain in an elite cyclist with Non-Hodgkin's Follicular Lymphoma: a case report

OBJECTIVE

We present a case of an elite cyclist that hesitated to follow the medical advice from her practitioners, as she was determined to train and compete resulting in delayed diagnosis and management of a rare hip pathology.

CASE PRESENTATION

A 51-year old elite female cyclist had a history of years of hip pain with insidious onset. The chiropractor in this case observed a lack of response to treatment, and advised the patient to get an MRI with suspicion of a labral tear. She eventually agreed to further investigations and was diagnosed with Non-Hodgkin's follicular lymphoma and a labral tear.

SUMMARY

Elite athletes are not immune to serious pathology. Chiropractors should be vigilant and ensure to investigate any patients with a lack of response to conservative management. Chiropractors should be aware of the risk of athletic patients that continue to train and compete when advised not to.

Characteristics of Pedaling Muscle Stiffness among Cyclists of Different Performance Levels

Background and Objectives: The aim of the present study was to compare the impact of an incremental exercise test on muscle stiffness in the rectus femoris (RF), vastus lateralis (VL), biceps femoris (BF), and gastrocnemius (GL) among road cyclists of three performance levels. Materials and Methods: The study group consisted of 35 cyclists grouped according to their performance level; elite (n = 10; professional license), sub-elite (n = 12; amateur license), and recreational (n = 13; cyclosportive license). Passive muscle stiffness was assessed using myometry before and after an incremental exercise test. Results: There was a significant correlation between time and category in the vastus lateralis with stiffness increases in the sub-elite (p = 0.001, Cohen's d = 0.88) and elite groups (p = 0.003, Cohen's d = 0.72), but not in the recreational group (p = 0.085). Stiffness increased over time in the knee extensors (RF, p < 0.001; VL, p < 0.001), but no changes were observed in the knee flexors (GL, p = 0.63, BF, p = 0.052). There were no baseline differences among the categories in any muscle. Conclusions: Although the performance level affected VL stiffness after an incremental exercise test, no differences in passive stiffness were observed among the main muscles implicated in pedaling in a resting state. Future research should assess whether this marker could be used to differentiate cyclists of varying fitness levels and its potential applicability for the monitoring of training load.

Temporal Location of High-Intensity Interval Training in Cycling Does Not Impact the Time Spent Near Maximal Oxygen Consumption

PURPOSE

To examine the influence of temporal location of high-intensity interval training (HIIT) within a cycling session on the time spent ≥90% of maximal oxygen consumption and physiological and perceptual responses.

METHODS

In a randomized, crossover design, 16 trained cyclists (male, n = 13 and female, n = 3) completed three 90-minute cycling sessions with HIIT placed at the beginning, middle, or end of the session (13, 36, and 69 min, respectively). Intervals consisted of three 3-minute efforts at 90% of the power output associated with maximal oxygen consumption interspersed with 3 minutes of recovery. Oxygen consumption, minute ventilation, respiratory rate, and heart rate were recorded continuously during work intervals. Rate of perceived exertion was recorded at the end of work intervals, and sessional rate of perceived exertion was collected 20 minutes after session completion.

RESULTS

No differences were observed for mean oxygen consumption (P = .479) or time spent ≥90% maximal oxygen consumption (P = .753) between condition. The mean rate of perceived exertion of all intervals were greater in the Middle (P < .01, effect size = 0.83) and End (P < .05, effect size = 0.75) compared with Beginning conditions. Mean minute ventilation was greater in the End compared with Beginning condition (P = .015, effect size = 0.63). However, no differences in mean respiratory rate were observed between conditions (P = .297).

CONCLUSIONS

Temporal location of HIIT has no impact on oxygen consumption or cardiovascular stress within a cycling session. However, HIIT performed later in the session resulted in higher ventilation, which may indicate the need for greater anaerobic contribution to these intervals.

Elevated peak systolic blood pressure in endurance-trained athletes: Physiology or pathology?

Blood pressure is a function of cardiac output and peripheral vascular resistance. During graded exercise testing (GXT), systolic blood pressure (SBP) is expected to increase gradually along with work rate, oxygen consumption, heart rate, and cardiac output. Individuals exposed to chronic endurance training attain a greater exercise SBP than in their untrained state and sedentary counterparts, but it is currently unknown what is considered a safe upper limit. This review discusses key studies examining blood pressure response in sedentary individuals and athletes. We highlight the physiological characteristics of highly fit individuals in terms of cardiovascular physiology and exercise blood pressure and review the state of the current literature regarding the safety of high SBP during exercise in this particular subgroup. Findings from this review indicate that a consensus on what is a normal SBP response to exercise in highly fit subjects and direct causation linking high GXT SBP to pathology is lacking. Consequently, applying GXT SBP guidelines developed for a "normal" population to endurance-trained individuals appears unsupported at this time. Lack of evidence for poor outcomes leads us to infer that elevated peak SBP in this subgroup could more likely reflect an adaptive response to training, rather than a pathological outcome. Future studies should track clinical outcomes of those achieving elevated SBP and develop athlete-specific guidelines.

Driver knowledge of cycling-related road rules in Queensland, Australia

OBJECTIVES

Violations of road rules are common in bicycle-motor vehicle crashes, but little is known about how much this results from lack of knowledge of the rules. This article addresses the research questions of how well do drivers know the road rules related to interacting with cyclists, and what factors influence their level of knowledge.

METHODS

An online survey compared drivers who reported riding bicycles on Queensland roads in the previous 12 months ("cyclists": n = 2,839) and those who did not ("drivers": n = 4,070). A list of 10 plausible road rules (four were not actual rules) relating to interactions between motor vehicles and bicycles was presented, and participants were asked "Which of the following road rules applies in Queensland?" The response options for each item were "Yes," "No," and "I don't know".

RESULTS

The percentages correct varied markedly across the rules, from 86.5% to 38.7% for cyclists and from 72.2% to 20.9% for drivers. Incorrect responses were generally more common than "Don't know" responses (cyclists: 22.3% incorrect, 9.8% "Don't know"; drivers: 29.9% incorrect, 19.6% "Don't know"). The hierarchical regression analysis confirmed that cyclists had better road rule knowledge than drivers. In the cyclist-only model, more frequent riding was significantly associated with better road rule knowledge but explained only 3% of the total variance. Older cyclists and those living in more urbanized areas had better knowledge but age and location of residence together added only 1% to the variance explained. In the driver-only model, knowledge was better for male, older, more educated participants and those living in more urbanized areas but these variables together accounted for only 5% of the variance.

CONCLUSIONS

The results of this study suggest that improving knowledge of some current road rules could be beneficial for cycling safety but for some other rules, improved knowledge could be detrimental for cycling safety and changing the rules to reflect shared perceptions of safe behavior may be more beneficial. For each of the rules, further research is needed to examine the links between knowledge and compliance, and the influence of compliance on the risks of bicycle-motor vehicle crashes and near misses.

Analysis of kinematic behavior of pedestrians/cyclists in vehicle collisions using impulse

Objective: In order to further reduce the injury risks to pedestrians/cyclists in vehicle collisions, it is necessary to control pedestrian/cyclist kinematics. To investigate pedestrian/cyclist kinematic behavior from initial contact with the vehicle to the ground contact, it is necessary to evaluate the force interactions between the pedestrian/cyclist body region and the car body during the crash event.Method: Finite element analysis was conducted for models of pedestrians and cyclists being struck by a car around the center, left, and right sides of the front of the vehicle at 40 km/h. The impulse that was applied to each body region of the pedestrian/cyclist by the vehicle body during the impact was employed to analyze the kinematic behavior of the pedestrian/cyclist.Results: An impulse-time history can be separated into three stages. In the first stage, the pedestrian/cyclist was accelerated by the vehicle's forward impulse imparted to the subject due to the lower extremities contacting the bumper and hood leading edge. In the second stage, the pedestrian/cyclist rotates around the hood leading edge. In the third stage, the pedestrian/cyclist was accelerated in the vehicle forward and upward directions by the impulse resulting from the contact of the head and upper extremities with the cowl and the windshield. As the impulse to the lower extremity increased, the wraparound distance (WAD) decreased; however, the pelvis velocity in the forward direction increased.Conclusion: This research employed a new approach using the impulse transmitted to each body region due to contact with the vehicle body and showed that impulse is a useful parameter to understand the process of pedestrian/cyclist kinematics. The impulse relates to the linear and angular velocities of the pedestrian/cyclist at the time of separation from the car, thereby providing useful information to control pedestrian/cyclist falling kinematics prior to the ground impact.

Mapping fractures from traffic accidents in Sweden: How do cyclists compare to other road users?

Introduction: Cyclists account for a large share of injured road users in traffic. The crash data analysis for cyclist safety and protection should be based on a representative dataset of real-world crashes. This manuscript aimed to explore the patterns of cyclists' fractures and factors associated with fractures of higher severity.Methods: This paper exemplifies a methodology that combines injuries from a crash database, including both hospital and police reports and fracture registry database from orthopedic centers nationally in Sweden.Results: Car occupants were most frequently involved in crashes resulting in fractures (37%), followed by motorcyclists (27.6%) and bicyclists (15.4%). Common fracture locations differed by the type of road user, where cyclists were more frequently fractured in the lower arm, compared to other road users, such as car drivers, motorcyclists and pedestrians who suffered mostly of fractures in the lower leg. Within cyclists, injuries also differed by gender, suggesting that combination of different countermeasures may be needed in order to provide sufficient protection for all cyclist. In the analyzed data, male cyclists with an average age of 49 were the most frequently fractured cyclists. Fractures of cyclists to the acetabulum (100%), pelvis (84.2%), vertebra (75%) and tibia (70.3%) were most frequently high energy fractures. Single bicycle incidents (OR = 0.165) and collisions with another bicycle (OR = 0.148) were significantly less likely to result in a high energy fracture than a collision with a car.Conclusions: The results of this study may guide the design of appropriate protective devices for the cyclists based on the different injury mechanisms and provide implications for prioritizing new countermeasures, campaigns, or regulations.

Time to exhaustion during cycling is not well predicted by critical power calculations

Three to 5 cycling tests to exhaustion allow prediction of time to exhaustion (TTE) at power output based on calculation of critical power (CP). We aimed to determine the accuracy of CP predictions of TTE at power outputs habitually endured by cyclists. Fourteen endurance-trained male cyclists underwent 4 randomized cycle-ergometer TTE tests at power outputs eliciting (i) mean Wingate anaerobic test (WAnT_mean), (ii) maximal oxygen consumption, (iii) respiratory compensation threshold (VT₂), and (iv) maximal lactate steady state (MLSS). Tests were conducted in duplicate with coefficient of variation of 5%-9%. Power outputs were 710 ± 63 W for WAnT_mean, 366 ± 26 W for maximal oxygen consumption, 302 ± 31 W for VT₂ and 247 ± 20 W for MLSS. Corresponding TTE were 00:29 ± 00:06, 03:23 ± 00:45, 11:29 ± 05:07, and 76:05 ± 13:53 min:s, respectively. Power output associated with CP was only 2% lower than MLSS (242 ± 19 vs. 247 ± 20 W; P < 0.001). The CP predictions overestimated TTE at WAnT_mean (00:24 ± 00:10 mm:ss) and MLSS (04:41 ± 11:47 min:s), underestimated TTE at VT₂ (-04:18 ± 03:20 mm:ss; P < 0.05), and correctly predicted TTE at maximal oxygen consumption. In summary, CP accurately predicts MLSS power output and TTE at maximal oxygen consumption. However, it should not be used to estimate time to exhaustion in trained cyclists at higher or lower power outputs (e.g., sprints and 40-km time trials). Novelty CP calculation enables to predict TTE at any cycling power output. We tested those predictions against measured TTE in a wide range of cycling power outputs. CP appropriately predicted TTE at maximal oxygen consumption intensity but err at higher and lower cycling power outputs.

Differing Physiological Adaptations Induced by Dry and Humid Short-Term Heat Acclimation

PURPOSE

To investigate the effect of a 5-day short-term heat acclimation (STHA) protocol in dry (43°C and 20% relative humidity) or humid (32°C and 80% relative humidity) environmental conditions on endurance cycling performance in temperate conditions (21°C).

METHODS

In a randomized, cross-over design, 11 cyclists completed each of the two 5-day blocks of STHA matched for heat index (44°C) and total exposure time (480 min), separated by 30 days. Pre- and post-STHA temperate endurance performance (4-min mean maximal power, lactate threshold 1 and 2) was assessed; in addition, a heat stress test was used to assess individual levels of heat adaptation.

RESULTS

Differences in endurance performance were unclear. Following dry STHA, gross mechanical efficiency was likely reduced (between-condition effect size dry vs humid -0.59; 90% confidence interval, -1.05 to -0.15), oxygen uptake was likely increased for a given workload (0.64 [0.14 to 1.07]), and energy expenditure likely increased (0.59 [0.17 to 1.03]). Plasma volume expansion at day 5 of acclimation was similar (within-condition outcome 4.6% [6.3%] and 5.3% [5.1%] dry and humid, respectively) but was retained for 3 to 4 days longer after the final humid STHA exposure (-0.2% [8.1%] and 4.5% [4.2%] dry and humid, respectively). Sweat rate was very likely increased during dry STHA (0.57 [0.25 to 0.89]) and possibly increased (0.18 [-0.15 to 0.50]) during humid STHA.

CONCLUSION

STHA induced divergent adaptations between dry and humid conditions, but did not result in differences in temperate endurance performance.

An Epidemiological Study of the Risk Factors of Bicycle-Related Falls Among Japanese Older Adults

Background

Considering the rate of growth of the older population in several countries, accidental falls in older cyclists are expected to increase. However, the prevalence and correlates of bicycle-related falls (BR-falls) are unknown. The aim of the present study was to explore the characteristics of BR-falls, focusing on the risk factors.

Methods

Seven-hundred and ninety-one older adults participated in a comprehensive baseline assessment that included questions on bicycle use, BR-falls, lifestyle, and physical and cognitive evaluations. A cyclist was defined as a person who cycled at least a few times per month. The incidence of BR-falls in participants who did not report BR-falls at baseline was again ascertained 3 years later. Logistic regression analyses examined the predictors of BR-falls incidence.

Results

At baseline, 395 older adults were cyclists and 45 (11.4%) of them had experienced BR-falls. Adjusted regression analysis showed that slower gait velocity, shorter one-leg standing time, and experience of falls (ie, non-BR-falls) were associated with BR-falls. Among the 214 cyclists who did not report BR-falls at baseline and who participated in both baseline and follow-up assessments, 35 (16.4%) cyclists experienced BR-falls during the 3-year follow-up. Adjusted regression analysis revealed that higher body mass index and non-BR-falls were predictors of future incidence of BR-falls, independent of physical function.

Conclusions

Our results showed that experience of falls, irrespective of bicycling, is an independent correlate and risk factor of BR-falls. This suggests that experience of falls and BR-falls may share the same risk factors.

Personality and Behavioral Predictors of Cyclist Involvement in Crash-Related Conditions

In recent years, the increasing rate of road crashes involving cyclists with a disproportionate overrepresentation in injury statistics has become a major concern in road safety and public health. However, much remains unknown about factors contributing to cyclists’ high crash rates, especially those related to personal characteristics. This study aims to explore the influence of cyclist personality traits and cycling behaviors on their road safety outcomes using a mediated model combining these constructs. A total of 628 cyclists completed an online questionnaire consisting of questions related to cycling anger, impulsiveness, normlessness, sensation seeking, risky cycling behaviors, and involvement in crash-related conditions in the past year. After the psychometric properties of the employed scales were examined, the relationships among the tested constructs were investigated using structural equation modeling. The results showed that cyclists’ crash risks were directly predicted by risky cycling behaviors and cycling anger, and the effects of cycling anger, impulsiveness, as well as normlessness on crash risks, were mediated by cycling behaviors. The current findings provide insight into the importance of personality traits in impacting cycling safety and could facilitate the development of evidence-based prevention and promotion strategies targeting cyclists in China.

Prospective assessment of the effectiveness of autonomous emergency braking in car-to-cyclist accidents in France

Objective: This study aimed to assess the effectiveness of autonomous emergency braking (AEB) systems in car-to-cyclist frontal collisions by simulating their effects, in terms of crash avoidance and injury mitigation, on a representative target population of real-world accidents. Identifying effectiveness-critical AEB-cyclist design parameters through a sensitivity analysis was also targeted.Methods: The analysis is based on a representative set of real-world car-to-cyclist frontal collisions gathered from French police reports. AEB-cyclist-relevant accident cases were first selected and used to build injury risk curves for fatal, severe, and slight cyclist injuries. The effect of AEB-cyclist on these cases was then simulated by means of a car kinematic model involving sensor detection strategies and actuator actions. Combining the resulting simulated impact speed distributions with the injury risk curves allowed to assess AEB-cyclist's effectiveness in terms of lives saved and mitigated injuries. Using design of experiments methods, the sensitivity of this effectiveness with regards to AEB-cyclist design parameters could be assessed.Results: Cyclist injury risks curves were built, along with their confidence intervals, for fatal, severe, and slight injuries using a polytomous complementary log-log regression model, with squared impact speed as an independent variable. A sensitivity analysis on an ideal bisensor AEB-cyclist setting highlighted influential design parameters such as maximal braking intensity or crucial decision algorithm parameters such as maximal time and distance to collision thresholds. AEB-cyclist effectiveness was nevertheless shown to range from 35% to 59% in fatalities, 14% to 54% in severe injuries, and 11% to 42% in slight injuries, depending on field of view parameters alone, once reference values of decision algorithm parameters had been set.Conclusions: This study illustrates the potential benefits and limits of AEB-cyclist systems. High-end systems show acceptable effectiveness rates, but road safety performance strongly depends on external factors such as road surface conditions or has to be tuned in order to avoid unnecessary activations and driver discomfort. Limits of the system's everyday use (lack of maintenance, driver reaction time to collision warnings, etc.) were not taken into account, thus resulting in optimistic evaluations of AEB-cyclist effectiveness.

Individual and environmental factors associated with death of cyclists involved in road crashes in Spain: a cohort study

OBJECTIVE

To quantify the magnitude of associations between cyclist fatalities and both cyclist and environment related characteristics in Spain during the first 24 hours after a crash.

DESIGN

Cohort study.

SETTING

Spain.

PARTICIPANTS

65 977 cyclists injured in road crashes recorded between 1993 and 2013 in the Spanish Register of Road Crashes with Victims.

MAIN OUTCOME

Death within the first 24 hours after the crash.

METHODS

A multiple imputation procedure was used to mitigate the effect of missing values. Differences between regions were assumed and managed with multilevel analysis at the cyclist and province levels. Incidence density ratios (IDR) with 95% CI were calculated with a multivariate Poisson model.

RESULTS

Non-use of a helmet was directly associated with death (IDR 1.43, 95% CI 1.25 to 1.64). Among other cyclist characteristics, age after the third decade of life was also directly associated with death, especially in older cyclists ('over 74' category, IDR 4.61, 95% CI 3.49 to 6.08). The association with death did not differ between work-related cycling and other reasons for cycling.There was an inverse association with death for crashes in urban areas and on community roads. Any adverse meteorological condition also showed a direct association with death, whereas altered road surfaces showed an inverse association. Crashes during nighttime were directly associated with death, with a peak between 3:00 and 5:59 am (IDR 1.58, 95% CI 1.03 to 2.41).

CONCLUSIONS

We found strong direct and inverse associations between several cyclist and environment related variables and death. These variables should be considered in efforts to prioritise public health measures aimed at reducing the number of cycling-related fatalities.

A simulator study of driving behavior and mental workload in mixed-use arterial road environments

Objectives: Mixed-use urban environments, such as arterial roads with adjacent commercial land uses, represent crash locations with the highest risk. These locations are often characterized by high volumes of motor vehicle traffic, on-street parking, and interactions with multiple road user groups such as pedestrians, cyclists, and public transportation. The objective of this study was to investigate previously identified crash risk factors for mixed-use urban environments and assess how parking occupancy, center medians, and cyclist volume influence performance and workload in a driving simulator study. Methods: Thirty participants were recruited for the study. Participants completed 6 drives that presented different combinations of cyclist volume, median condition, and parking occupancy. Incorporated into the simulator drives was a secondary peripheral detection task (PDT) designed to measure mental workload. Participants provided subjective assessments of workload using the Rating Scale Mental Effort (RSME). Results: Mean lateral lane position was found to significantly vary across the 3 independent variables of parking occupancy, cyclist volume, and median conditions. No significant changes were identified for mean speed across the conditions. Subjective and objective measures of workload identified changes due to the presence of cyclists with slower reaction times for the PDT task when cyclists were present. Conclusion: The findings provide insight into the interaction of road design elements in mixed-use urban road environments and demonstrate that increasingly complex environments increase driver demand. This has important road design implications for mixed-use arterial roads, which are often characterized by complex interactions between multiple road user groups.

Effect of Iron Supplementation on the Modulation of Iron Metabolism, Muscle Damage Biomarkers and Cortisol in Professional Cyclists

Background: The intense efforts made during 3-week stage races may reduce iron metabolism and hematological parameters. These efforts may increase the levels of circulating muscle damage markers and some hormones. All of these physiological changes may have negative consequences not only for the performance of athletes but also for their health. The main aim of this study was to evaluate the effects of supplementation with 80 mg/day of iron on haematological parameters, serum cortisol and biochemical muscle indicators on elite male cyclists during the 3-week stage race the Vuelta a España. Our secondary aim was to examine whether the hematological profile is associated with muscular damage parameters and cortisol. Methods: Eighteen elite male cyclists from two teams were randomly assigned to one of two groups: (1) control group (CG, n = 9; age: 26.1 ± 4.6 years; maximum oxygen uptake per kg: 78.0 ± 5.4 mL/kg/min) or (2) group treated with 80 mg/day iron (800 mg of iron protein succinylate, ITG, n = 9; age: 25.7 ± 6.4 years; maximum oxygen uptake per kg: 77.6 ± 6.5 mL/kg/min). The cyclists were subjected to blood tests one week before the start of the race (T1) and after 4 weeks of treatment, coinciding with the end of the competition (T2). Iron metabolism parameters, muscle damage indicators and serum cortisol were assessed. Repeated-measures ANOVA with group as a factor (GC and ITG) were used to examine the differences between groups throughout the study (time × group) after iron supplementation treatment. Results: Significant differences were observed between groups throughout the study in the group-by-time interaction and changes in serum iron (GC: −8.93 ± 10.35% vs. ITG: 0.60 ± 8.64%; p = 0.018), ferritin (GC: −13.88 ± 23.53% vs. ITG: 91.08 ± 118.30%; p = 0.004), haemoglobin (GC: 10.00 ± 3.32% vs. ITG: 13.04 ± 5.64%; p < 0.001), haematocrit (GC: −1.17 ± 3.78% vs. ITG: 7.32 ± 3.92%; p < 0.001) and cortisol (GC: 24.74 ± 25.84% vs. ITG: –13.54 ± 13.61%; p = 0.005). However, no significant group-by-time interaction was observed for the circulating muscle biomarkers. Additionally, significant negative correlations of serum iron, haemoglobin and haematocrit with muscle circulating biomarkers and cortisol (p < 0.05) were observed. Conclusions: Oral iron supplementation with 80 mg/day iron (800 mg of iron protein succinylate) effectively prevented a decline in haematological parameters (serum iron, ferritin, haemoglobin and haematocrit) and maintained optimal levels of recovery in elite cyclists during the Vuelta a España. Moreover, the hematological values were shown to have relationship with muscular recovery parameters.

Forward collision warning based on a driver model to increase drivers' acceptance

Objective: Systems that can warn the driver of a possible collision with a vulnerable road user (VRU) have significant safety benefits. However, incorrect warning times can have adverse effects on the driver. If the warning is too late, drivers might not be able to react; if the warning is too early, drivers can become annoyed and might turn off the system. Currently, there are no methods to determine the right timing for a warning to achieve high effectiveness and acceptance by the driver. This study aims to validate a driver model as the basis for selecting appropriate warning times. The timing of the forward collision warnings (FCWs) selected for the current study was based on the comfort boundary (CB) model developed during a previous project, which describes the moment a driver would brake. Drivers' acceptance toward these warnings was analyzed. The present study was conducted as part of the European research project PROSPECT ("Proactive Safety for Pedestrians and Cyclists"). Methods: Two warnings were selected: One inside the CB and one outside the CB. The scenario tested was a cyclist crossing scenario with time to arrival (TTA) of 4 s (it takes the cyclist 4 s to reach the intersection). The timing of the warning inside the CB was at a time to collision (TTC) of 2.6 s (asymptotic value of the model at TTA = 4 s) and the warning outside the CB was at TTC = 1.7 s (below the lower 95% value at TTA = 4 s). Thirty-one participants took part in the test track study (between-subjects design where warning time was the independent variable). Participants were informed that they could brake any moment after the warning was issued. After the experiment, participants completed an acceptance survey. Results: Participants reacted faster to the warning outside the CB compared to the warning inside the CB. This confirms that the CB model represents the criticality felt by the driver. Participants also rated the warning inside the CB as more disturbing, and they had a higher acceptance of the system with the warning outside the CB. The above results confirm the possibility of developing wellsaccepted warnings based on driver models. Conclusions: Similar to other studies' results, drivers prefer warning times that compare with their driving behavior. It is important to consider that the study tested only one scenario. In addition, in this study, participants were aware of the appearance of the cyclist and the warning. A further investigation should be conducted to determine the acceptance of distracted drivers.

Factors involved in the assessment of paediatric traffic injuries and deaths

Motor-vehicle collisions are the leading cause of unintentional injury and death in children in many parts of the world, including Europe, North America and Australia. The number of fatal collisions has decreased considerably in countries where safety measures such as child restraints, seat belts and air bags have been introduced, providing protection for children within vehicles, although it is recognised that there have been concomitant improvements in emergency responses and techniques, and in hospital treatments. Helmets and changes in external vehicle designs have been implemented to protect paediatric pedestrians and cyclists. However, despite the development of safety guidelines and technologies, injuries still occur. This paper provides an overview of the role of motor-vehicle collisions in paediatric morbidity and mortality to analyse the nature and aetiology of common fatal and non-fatal injuries in children that may present for forensic assessment as passengers, pedestrians or cyclists.

Sprinting for the Win: Distribution of Power Output in Women's Professional Cycling

PURPOSE

To examine the power-output distribution and sprint characteristics of professional female road cyclists.

METHODS

A total of 31 race files, representing top 5 finishes, were collected from 7 professional female cyclists. Files were analyzed for sprint characteristics, including mean and peak power output, velocity, and duration. The final 20 min before the sprint was analyzed to determine the mean maximal power output (MMP) consistent with durations of 5, 15, 30, 60, 240, and 600 s. Throughout the race, the number of efforts for each duration exceeding 80% of its corresponding final 20-min MMP (MMP₈₀) was determined. The number of 15-s efforts exceeding 80% of the mean final sprint power output (MSP₈₀) was determined.

RESULTS

Sprint finishes lasted 21.8 (6.7) s with mean and peak power outputs of 679 (101) and 886 (91) W, respectively. Throughout the race, additional 5-, 15-, and 30-s efforts above MMP₈₀ were completed in the 5th compared with the 1st-4th quintiles of the race. The 60-s efforts were greater during the 5th quintile compared with the 1st, 2nd, and 4th quintiles, and during the 3rd compared with the 4th quintile. More 240-s efforts were recorded during the 5th compared with the 1st and 4th quintiles. About 82% of the 15-s efforts above MSP₈₀ were completed in the 2nd, 3rd, and 5th quintiles of the race.

CONCLUSIONS

These data demonstrate the variable nature of women's professional cycling and the physical demands necessary for success, thus providing information that could enhance in-race decision making and the development of race-specific training programs.

Reflective Tape Applied to Bicycle Frame and Conspicuity Enhancement at Night

OBJECTIVE

Four studies were conducted to assess bicyclist conspicuity enhancement at night by the application of reflective tape (ECE/ONU 104) to the bicycle rear frame and to pedal cranks.

BACKGROUND

Previous studies have tested the benefits of reflective markings applied to bicyclist clothing. Reflective jackets however need to be available and worn while reflective markings enhance conspicuity without any active behavior by the bicyclist.

METHOD

In the first study, reflective tape was applied to the rear frame. Detection distance was compared in four conditions: control, rear red reflector, high visibility jacket, and reflective tape. In the second study, the same conditions were studied with night street lighting on and off. In the third study, detection and recognition distances were evaluated in rainy conditions. In the fourth study, visibility was assessed with the reflective tape applied to pedal cranks.

RESULTS

In the first study, the application of reflective markings resulted in a detection distance of 168.28 m. In the second study, the detection distance with reflective markings was 229.74 m with public street light on and 256.41 m with public street light off. In rainy conditions, detection distance using the reflective markings was 146.47 m. Reflective tape applied to pedal cracks resulted in a detection distance of 168.60 m.

CONCLUSION

Reflective tape applied to the rear bicycle frame can considerably increase bicyclist conspicuity and safety at night.

APPLICATION

Reflective tape is highly recommended to complement anterior and rear lights in bicycle riding at night.

A Systematic Review of Submaximal Cycle Tests to Predict, Monitor, and Optimize Cycling Performance

Finding the optimal balance between high training loads and recovery is a constant challenge for cyclists and their coaches. Monitoring improvements in performance and levels of fatigue is recommended to correctly adjust training to ensure optimal adaptation. However, many performance tests require a maximal or exhaustive effort, which reduces their real-world application. The purpose of this review was to investigate the development and use of submaximal cycling tests that can be used to predict and monitor cycling performance and training status. Twelve studies met the inclusion criteria, and 3 separate submaximal cycling tests were identified from within those 12. Submaximal variables including gross mechanical efficiency, oxygen uptake (VO₂), heart rate, lactate, predicted time to exhaustion (pTE), rating of perceived exertion (RPE), power output, and heart-rate recovery (HRR) were the components of the 3 tests. pTE, submaximal power output, RPE, and HRR appear to have the most value for monitoring improvements in performance and indicate a state of fatigue. This literature review shows that several submaximal cycle tests have been developed over the last decade with the aim to predict, monitor, and optimize cycling performance. To be able to conduct a submaximal test on a regular basis, the test needs to be short in duration and as noninvasive as possible. In addition, a test should capture multiple variables and use multivariate analyses to interpret the submaximal outcomes correctly and alter training prescription if needed.

The effects of cyclists present at rural intersections on speed behavior and workload of car drivers: a driving simulator study

OBJECTIVE

The objective was to gain insight into how the number of cyclists, the cyclist's approach direction, and the cyclist's action affect the speed and mental workload of drivers approaching rural intersections. In addition, the effects of a speed-reducing measure on the interaction between cyclists and motorized traffic were examined.

METHODS

An experiment was conducted in a moving-base driving simulator. Thirty participants completed 3 runs each in 3 conditions: a baseline, a plateau, and a chicane condition. Participants drove an 80 km/h rural distributor road with 8 intersections. Eight cyclist scenarios were developed varying in the number of cyclists and the direction from which they approached the participants' lane. The Peripheral Detection Task was used to measure workload objectively and continuously.

RESULTS

A plateau ahead of the intersection resulted in drivers entering the bicycle crossing with lower driving speeds but did not result in less serious potential conflicts compared to intersections without the speed-reducing measure. With respect to the presence of cyclists, drivers approaching the intersection without cyclists reached a minimum speed at a greater distance from the bicycle crossing compared to approaching the intersection with multiple cyclists in the baseline condition. At intersections with plateaus, drivers drove slower when encountering multiple cyclists compared to no cyclists. At intersections without the speed-reducing measure, drivers drove slower, decelerated stronger, and decelerated at a shorter distance to the bicycle crossing when encountering a suddenly crossing cyclist compared to a yielding cyclist.

CONCLUSIONS

Although drivers have the right of way at rural intersections, drivers' speed behavior was affected by the number and action of cyclists. From a road safety point of view, driving speeds at rural intersections need to be further reduced to limit the seriousness of potential conflicts between cyclists and motorized traffic.

A study of fatality risk and head dynamic response of cyclist and pedestrian based on passenger car accident data analysis and simulations

OBJECTIVE

The current study aims to compare the fatality risk of pedestrians and cyclists in urban traffic through an analysis of real-world accident data in China.

METHODS

First, 438 cases, including 371 pedestrian cases and 67 cyclist cases, were selected as a sample from the accidents collected through an in-depth investigation of vehicle accidents in China. A statistical measurement of the fatality risk with respect to impact velocity was carried out using a logistic regression analysis. Furthermore, 21 pedestrian and 24 cyclist accidents were selected for reconstruction with the MADYMO program. A comparative analysis was conducted based on the results from accident analysis and simulations for the fatality risk and head dynamic response of pedestrians and cyclists.

RESULTS

The results indicate that the vehicle impact velocity has a significant relationship with the fatality risk of both pedestrians and cyclists. The fatality risks at 50 km/h are more than twice as high as the risk at 40 km/h and about 5 times as high as that at 30 km/h for both pedestrians and cyclists. Moreover, cyclists suffered slightly lower fatality risk compared to pedestrians. The corresponding vehicle impact velocity is 65.4 km/h for pedestrian with a fatality risk of 50 percent, whereas for cyclists it is 67.6 km/h. In addition, the head impact conditions between pedestrians and cyclists are different.

CONCLUSIONS

These findings offer potential contributions for establishing a more reasonable speed limit for urban traffic in China and generating strategies for cyclists' and pedestrians' head protection.

A real-life based evaluation method of deployable vulnerable road user protection systems

OBJECTIVE

The aim of this study was to develop a real-life-based evaluation method, incorporating vulnerable road user (VRU) full-body loading to a vehicle with a deployable protection system in relevant test setups, and use this method to evaluate a prototype pedestrian and cyclist protection system.

METHODS

Based on accident data from severe crashes, the most common scenarios were selected and developed into 5 test setups, 2 for pedestrians and 3 for bicyclists. The Polar II pedestrian anthropomorphic test device was used, either standing or on a standard bicycle. These test setups could then be used to evaluate real-life performance of a prototype protection system, regarding both positioning and protection, for vulnerable road users. The protection system consisted of an active hood and a windshield airbag and was mounted on a large passenger car with a conventional hood-type front end. Injury evaluation criteria were selected for head, neck, and chest loading derived from occupant frontal and side impact test methods.

RESULTS

The protection system managed to be fully deployed, obtaining the intended position in time-that is, before VRU body contact-in all test setups, and head protection potential was not negatively influenced by the preceding thoracic impact. Head loading resulted in head injury criterion (HIC) values ranging up to 4400 for the standard car, and all HIC values were below 650 with the protection system. The risk of severe (Abbreviated Injury Scale [AIS] 3+) head injury decreased from 85% to 100% in 3 test setups (mainly to the windscreen frame), to less than a 20% risk in all setups. In general, there were larger differences between structures impacted than between the pedestrian and cyclist setup. Neck loading was maintained at an acceptable level or was slightly decreased by the protection system, and chest loading was decreased from high values in 2 test setups in which the cyclist was impacted laterally with chest impact mainly to the hood area.

CONCLUSIONS

A test method was developed to evaluate a more real-life-based test condition, as a complement to current component test methods. Being real-life based, including full-body loading, it is suggested as a complementary test method to the more simplified legal and rating component tests. Together these test methods will provide a more thorough evaluation of a protection system. The evaluated protection system performed well regarding both positioning and protection, indicating a capability to obtain the intended position in time with the potential to prevent the most common severe upper-body injuries of a pedestrian or cyclist in typical real-life accidents, without introducing negative side effects.

Ganglion cyst of the foot treated with electroacupuncture: A case report

OBJECTIVE

To present the clinical management of a ganglion cyst presenting on the dorsolateral aspect of the foot.

CLINICAL FEATURES

A 45-year-old female cyclist complaining of ganglion cyst following training period.

INTERVENTION AND OUTCOME

Patient was treated with high-frequency electroacupuncture in four consecutive sessions over four weeks, and reported resolution of the cyst following therapeutic intervention.

CONCLUSIONS

Ganglion cysts of the foot are relatively rare connective tissue tumours with variable treatment approaches. Electroacupuncture may be a novel and non-invasive conservative approach for the treatment of ganglion cysts. Further evaluation of the efficacy of such treatment is warranted.

Active transportation safety features around schools in Canada

The purpose of this study was to describe the presence and quality of active transportation safety features in Canadian school environments that relate to pedestrian and bicycle safety. Variations in these features and associated traffic concerns as perceived by school administrators were examined by geographic status and school type. The study was based on schools that participated in 2009/2010 Health Behaviour in School-aged Children (HBSC) survey. ArcGIS software version 10 and Google Earth were used to assess the presence and quality of ten different active transportation safety features. Findings suggest that there are crosswalks and good sidewalk coverage in the environments surrounding most Canadian schools, but a dearth of bicycle lanes and other traffic calming measures (e.g., speed bumps, traffic chokers). Significant urban/rural inequities exist with a greater prevalence of sidewalk coverage, crosswalks, traffic medians, and speed bumps in urban areas. With the exception of bicycle lanes, the active transportation safety features that were present were generally rated as high quality. Traffic was more of a concern to administrators in urban areas. This study provides novel information about active transportation safety features in Canadian school environments. This information could help guide public health efforts aimed at increasing active transportation levels while simultaneously decreasing active transportation injuries.

Exercise electrocardiogram testing in two brothers with different outcome - a case study exercise testing in master cyclists

The cases of two brothers training and competing as master cyclists and both preparing for a cycling tour are presented. The older brother aged 66 years went first to the primary care physician and presented with an asymptomatic depression in the exercise stress test of the ST segment in V5 and V6 during recovery after complete exhaustion. Coronary angiography revealed a multi vessel coronary artery disease and he underwent bypass surgery. One year later, he successfully completed his planned cycling tour of ~600 km in seven stages and covering ~12,000 m of total ascent. The younger brother aged 59 years went a few months later to the primary care physician and also performed asymptomatic exercise stress testing without changes in the ST segments. Unfortunately, 2 months later he suffered a cardiac arrest during his cycling tour and survived following immediate successful cardiopulmonary resuscitation on the road by his cycling colleagues. Immediate invasive coronary arteriography showed a complete stenosis of the trunk of arteria coronaria sinistra (left coronary artery), a 40%-50% stenosis of ramus circumflexus, and a 20% stenosis of arteria coronaria dextra (right coronary artery). The left coronary artery was dilated and he continued cycling 2 months later. In both brothers, familial hypercholesterolemia was the main cardiovascular risk factor for the multi vessel coronary artery disease. A negative exercise electrocardiogram in siblings with an increased risk for coronary artery disease seemed not to exclude an advanced multi vessel coronary artery disease. In master athletes with asymptomatic exercise electrocardiogram but a positive family history, further examinations should be performed in order to detect relevant stenosis in coronary arteries.

Effects of a herbal drink on cycling endurance performance

In this study, we examined the effects of acute ingestion of a herbal drink (H) or a coloured water placebo (P) on physiological responses and performance during cycling exercise. Eight healthy and trained male young cyclists (age: 16.0±0.5years) exercised on a cycle ergometer at 72.0±0.8% of the maximal oxygen consumption (VO(2max)) until exhaustion in a room maintained at 23.9±0.2 °C and 64.2±1.6% relative humidity on two occasions, 1-week apart. During each exercise bout, subjects received 3ml.kg(-1) body weight of H or P every 20 minutes in a double-blind randomised study design. There was no significant difference between H and P trials in the total work time to exhaustion (84.5±5.1 and 82.3±5.6 min respectively). Changes in heart rate, oxygen consumption, plasma glucose concentrations, plasma lactate concentrations, rectal temperature, respiratory exchange ratio and energy expenditure were similar with both type of drinks. Loss of plasma volume was also similar with both drinks. Herbal drink elicited similar physiological responses, thermoregularity responses and exercise performances during endurance cycling when compared to the placebo ingestion. Thus, it can be concluded that the ingredient in the herbal drink did not provide any added advantage to cycling endurance performance.