Road Bicycle Research Articles

Проблеми транспортної інфраструктури Одеси та пректи для їх вирішення

В статті розглядаються основні проблеми транс-портної інфраструктури Одеси, причини їх виникнення та наслідки. Головними є: недостатня кількість дорожніх об’єктів для здійснення зв’язку центральної частини міста з мікрорайонами, недостатність магістралей, відсутність системи невуличного транспорту (у тому числі для забезпечення морських прибережних сполучень), чіткого призначення велодоріжок, проблеми парковок та ін. Розглядаються цілі проектів, спрямовані на поліпшення ситуації, що склалася.

The Association Between Pelvic Discomfort and Erectile Dysfunction in Adult Male Bicyclists

BackgroundBicycle riding's impact on erectile function remains a topic of great interest given cycling's popularity as a mode of transportation and exercise. AimWe evaluated risk factors for sexual dysfunction in male cyclists with the primary intention of determining if genital/pelvic pain and numbness are associated with erectile dysfunction (ED). MethodsWe surveyed male cyclists using an online anonymous questionnaire. Cyclists were queried on their demographics, cycling experience, and sexual function using the Sexual Health Inventory for Men (SHIM). ED was diagnosed when a completed SHIM score was <22. Regression analysis was used to evaluate the risk of ED in men with genital/pelvic pain or numbness after riding. The survey was designed in the United States. OutcomesQuantitative characterization of cycling habits, onset and timing of genital pain and numbness, and SHIM score. ResultsA total of 1635 participants completed the survey. A majority of men were over the age of 50 (58%, 934/1,607), Caucasian (88%, 1,437/1,635), had been active cyclists for over 10 years (63%, 1,025/1,635) and used road bikes (97%, 1,578/1,635). Overall, 22%, 30%, and 57% of men reported ED, genital pain, and genital numbness, respectively. While controlling for cohort demographics, body mass index, cycling intensity and equipment, and medical comorbidities, no saddle characteristics were associated with the risk of developing genital numbness. However, men reporting penile numbness were at higher risk of reporting ED (odds ratio [OR] = 1.453, P = .048). In addition, quicker onset of numbness and resolution of numbness within a day was associated with impaired erectile function. For example, numbness occurring less than 1 hour after cycling had greater odds of leading to ED than numbness after 5 hours (OR = 2.002, P = .032). Similarly, genital pain occurring less than 1 hour (OR = 2.466, P = .031) after cycling was associated with higher ED risk. Strengths & LimitationsStrengths include a large sample size of high-intensity cyclists and validated questionnaire use. Limitations include reliance on anonymous self-reported survey data and minimal inquiry into the riding preferences and terrain traversed by cyclists. ConclusionsPelvic pain and numbness are common complaints among male riders in the United States. Men with such complaints are more likely to also report ED especially if it occurs earlier in the ride. Although direction of causality and temporality are uncertain, alleviation of factors resulting in pelvic discomfort may reduce cycling's impact on sexual function. Such interventions are critical given that cycling for both active travel and aerobic exercise confers numerous health benefits.Balasubramanian A, Yu J, Breyer BN, et al. The Association Between Pelvic Discomfort and Erectile Dysfunction in Adult Male Bicyclists. J Sex Med 2020;17:919–929.

Life cycle cost analysis of Portland cement slurry seal and microsurfacing to correct rutting

ABSTRACTPortland cement slurry seal and microsurfacing can both be used as pavement preservation treatments to fill ruts, which extends service life and decreases road surface life cycle cost. Microsurfacing has a history for being a technically effective and cost-efficient solution for correcting pavement rutting in both asphalt and concrete pavement surfaces. On the other hand, Portland cement slurry seal is a relatively new product that provides an alternative rut filling solution. The potential of both treatments as rut fillers is generally unrecognized and as such, they are both underutilized in that role. This paper compares the life cycle costs of both treatments, using friction data as the primary performance indicator derived from field trial skid data collected over a period of 36 months on the same highway. The paper finds that each alternative performed comparably with regard to surface friction deterioration, and the life cycle cost output was such that either treatment is an economically feasible solution for filling ruts in both asphalt and concrete pavements.

Risk Factor Analysis of Bicycle Accidents Considering Geometric Features and Bicycle Road at Intersections

Risk Factor Analysis of Bicycle Accidents Considering Geometric Features and Bicycle Road at Intersections

Fuzzy control strategy of pure electric vehicle based on driving intention recognition

The main reason that currently hinders the commercialization of electric vehicles is a bottleneck in battery, motor and electronic control technology, however, an In-depth study of electronic control technology is one of the most effective means to break through this bottleneck at present. The purpose of this paper is to solve the problem that the pure electric vehicle is difficult to meet the driver’s acceleration intention in the urban road cycle acceleration work condition and the brake energy recovery process does not consider the battery state of charge during the deceleration work condition. Proposed a control strategy that can meet the requirements of road cycle conditions and driver’s driving intentions and take account of the vehicle operating status. Use a fuzzy control algorithm to develop a fuzzy controller that taking the motor demand speed change rate and battery state of charge as input, the motor demand torque compensation coefficient as output. The experimental results show that the modified control strategy can improve the actual output power, the actual output torque of the motor and actual driving force of the wheel under the premise of maintaining economy; it also improved the acceleration performance and climbing performance of pure electric vehicles, and can recycle braking energy efficiently. The experimental results show that the secondary development control strategy can meet the requirements of the cycle work condition CYC_ECE_EUDC for the speed and driving force and the driver’s driving intention under the premise of not sacrificing economics.

Analysis of sight distances at urban intersections from a vulnerable users’ approach: A case study

Road elements are predominantly designed to safely accommodate motorized users. Urban roads and streets, unlike highways, contain very dissimilar users and might have higher points of conflict. Nowadays, due to the increasing use of vehicle sharing systems, personal transportation devices and bicycle-friendly policies, some urban streets have had to adapt to distinct users with different levels of vulnerability. Given the interest in increasing the use of alternative transportation methods, it is of great importance to make sure these car-centered designed roads provide securely for all users. In order to create a safe environment for these unalike users, common measures such as reducing speed limits, traffic calming interventions and modifications to the road geometry have been taken in several urban areas. In this regard, taking into account the key role that proper available sight distance plays in road safety, the visibility of an urban roundabout located in Madrid, Spain was evaluated. This analysis was performed considering the observers to be pedestrians, cyclists and electric scooter riders. In addition to the estimation of their crossing and stopping sight distances, their reciprocal visibility with drivers was assessed. Nowadays there are different ways of obtaining up-to-date information of the road scene and cycle lanes with sufficient accuracy and detail, hence it is possible to easily perform offsite analyses of distinct road parameters. Here, the virtual verification of sufficient stopping and intersection sight distances was performed utilizing a LiDAR derived digital terrain model and 3-D geometries. These evaluations were performed with the objective of identifying potential risk locations for these vulnerable users and the proposal of measures that could improve their safety.

"제품 서비스 디자인을 위한 아이디어 시나리오 개발 방법론 연구 ; 로드바이크 사용자의 취약점 추출을 중심으로"

"제품 서비스 디자인을 위한 아이디어 시나리오 개발 방법론 연구 ; 로드바이크 사용자의 취약점 추출을 중심으로"

Um estudo dos graus de equivalência entre os termos denominativos das partes principais da bicicleta de estrada no Brasil e na França

O objetivo deste trabalho consiste em analisar a terminologia do domínio do ciclismo, mais particularmente da modalidade ciclismo de estrada, refletindo sobre os diferentes graus de equivalência mantidos entre os termos em português do Brasil e francês da França que denominam as partes principais da bicicleta de estrada. Para tanto, adotamos os princípios teóricos e metodológicos da Terminologia, sobretudo no que tange à Teoria Comunicativa da Terminologia (TCT) e aos critérios de delimitação da terminologia em pauta. Além disso, fundamentamo-nos na Terminologia Bilíngue, na medida em adotamos critérios que nos permitiram estabelecer os graus de equivalência entre as unidades terminológicas estudadas. Como resultados principais, verificamos que os graus de equivalência entre esses termos são, em sua maioria, totais. Há, no entanto, sete casos de equivalência parcial, uma vez que consideramos que esses termos não apresentam exatamente o mesmo uso no domínio do ciclismo de estrada no Brasil e na França.

Continuous Athlete Monitoring in Challenging Cycling Environments Using IoT Technologies

Internet of Things (IoT)-based solutions for sport analytics aim to improve performance, coaching, and strategic insights. These factors are especially relevant in cycling, where real-time data should be available anytime, anywhere, even in remote areas where there are no infrastructure-based communication technologies (e.g., LTE and Wi-Fi). In this article, we present an experience report on the use of state-of-the-art IoT technologies in cycling, where a group of cyclists can form a reliable and energy efficient mesh network to collect and process sensor data in real-time, such as heart rate, speed, and location. This data is analyzed in real-time to estimate the performance of each rider and derive instantaneous feedback. Our solution is the first to combine a local body area network to gather the sensor data from the cyclist and a 6TiSCH network to form a multihop long-range wireless sensor network in order to provide each bicycle with connectivity to the sink (e.g., a moving car following the cyclists). In this article, we present a detailed technical description of this solution, describing its requirements, options, and technical challenges. In order to assess such a deployment, we present a large publicly available data-set from different real-world cycling scenarios (mountain road cycle racing and cyclo-cross) which characterizes the performance of the approach, demonstrating its feasibility and evidencing its relevance and promising possibilities in a cycling context for providing low-power communication with reliable performance.

Current trends and injuries in cycling: faster, further, e-bike?

During the past decade, technical innovations (e.g., carbon as anew material, disk brakes, hydraulic shock absorbers, electric transmissions) and lifestyle changes have significantly influenced recreational and professional cycling. In contrast to the past, where ambitious leisure cyclists were primarily interested in the recreational value of nature and landscape, cyclists of all ages are nowadays increasingly focused on performance and self-optimization. Simultaneously, manufacturers have adapted to differing customer requirements: besides the traditional extremities of road and mountain bikes, many specialized models have been designed for special applications: trekking, cyclocross, gravel, full-suspension, single-track, hardtail, downhill, fatbike, etc. For biking fans who are no longer able to meet their own demands due to individual physical restrictions or defined health problems, electric-assist bikes (pedelecs or "e-bikes") were recently introduced. While these are becoming increasingly popular, they have also increased the number of accidents and injuries. The current work provides an update on relevant sport medical and orthopaedic challenges brought on by these developments in cycling.

Validity and reliability of the CycleOps Hammer direct drive trainer during sprint tests when compared with an SRM powermeter – a preliminary study

Background: Coaches and cyclists often use direct drive home-trainers for measuring power output (PO) during testing and training. Several devices like the Tacx Fortius (Peiffer et al., 2011: International Journal of Sports Medicine, 32, 353-356) and the Velotron trainer (Abbiss et al., 2009: International Journal of Sports Medicine, 30, 107-112) have been scientifically validated when compared to an SRM powermeter which is considered as the gold standard (Gardner et al., 2004: Medicine Science in Sports and Exercise, 36, 1252-1258). Contrarywise, others such as the Axiom Elite (Bertucci et al., 2005: International Journal of Sports Medicine, 26, 59-65) or the Kickr Power trainer (Zadow et al., 2016: International Journal of Sport Physiology and Performance, 11, 1115-1117) are less accurate and reliable. A recent study reported that the CycleOps Hammer provides valid and reliable PO measurements during graded exercise tests (100-500W). This validation procedure is nevertheless uncompleted as no comparison in maximal PO during all-out sprints have been done.  Purpose: The purpose of this study was to assess the validity and reliability of PO measurement of three Cycleops Hammer trainer devices during maximal sprint tests when compared to an SRM powermeter.  Methods: Three cyclists voluntarily participated in this study (Mean ± SD: 28 ± 9 years old; 1.81 ± 0.02 m; 72 ± 5 kg). Each subject performed three one-day laboratory test sessions separated by at least 48 h, that comprised successively: 1) one maximal graded exercise test (100-425 W) performed at a constant pedalling cadence (~90 rpm) ; 2) three 10-s all-out sprint tests against three different slope resistance (0.5%, 3%, 7%) ; 3) one 30-s all-out Wingate test (slope resistance of 3 %) ; and 4) a 20 min constant power test to study the potential power drift. All the tests were performed on the same road bike (Roubaix Tarmac, Specialized, USA) that was mounted on to a Hammer direct drive trainer (CycleOps, Madison, USA) and fitted with a SRM professional powermeter (SRM FSA K-Force Light, SRM GmbH, JA¼lich, Germany; accuracy ± 1 %). Prior to the study, the slope of the SRM powermeter was calibrated with set of weights. The zero offset of each device was performed according to the manufacturer’s recommendations before each test session. Power output (PO) and pedalling cadence (PC) were measured continuously by the two devices every second and stored in a GPS bike computer (Edge 520, Garmin, USA). The PO differences between the two devices was assessed by non-parametric Wilcoxon tests. To study the accuracy of each Hammer trainer, the relative bias of the PO differences between the SRM and the Hammer trainer and its 95% limits of agreement was defined using the Bland-Altman method. The 95% confidence interval (95%CI) for the relative bias was also calculated. All significant differences were set at p < 0.05. Only the data obtained during sprints and Wingate tests are presented in this abstract.  Results:  Significant differences in 1-s peak PO (sprints) and in 30-s mean PO (Wingate) were observed between the three Hammer devices and the SRM powermeter. When compared to the SRM powermeter, mean ± SD of bias for 1-s peak PO was 11.3 ± 10.3 % for Hammer 1, 13.2 ± 12.7% for Hammer 2 and 21.1 ± 9.5% for Hammer 3. Mean ± SD of bias for 30-s mean PO was 4.3 ± 3.0% for Hammer 1, 1.7 ± 2.4% for Hammer 2 and 5.5 ± 1.0% for Hammer 3. No significant differences were found in maximal (sprint) and mean pedalling cadence (Wingate) whatever the Hammer device used. Discussion and conclusion: These preliminary results seems to suggest that the CycleOps Hammer is not a valid device to measure PO with a high accuracy during all-out exercises as sprints. Nevertheless, according the lowest bias observed in 30-s mean PO during Wingate test, the overestimation of PO tends to decrease with increasing averaging time. Future studies should confirm it by increasing the sample size.

Power profiling in elite U23 riders during a competitive season

Power profiling in elite U23 riders during a competitive season Peter Leo 1 , Inigo Mujika 2 , Verena Menz and Justin Lawley 3 1 Cycling Team Tirol, Innsbruck Austria 2 University of the Basque Country 3 University of Innsbruck, Sports Science Department Background: Changes in the power profile of elite U23 cyclists throughout a competitive season could provide valuable information about racing demands and the training process. A rider’s power-duration relationship shows a dynamic behaviour affected by training and racing, and repeated computation is required to gain accurate insights into a rider’s performance capabilities. Assessing the power-duration relationship by means of different performance tests in the field is one common way to proceed. However, such tests require regular attempts as well as a motivated and rested athlete, which could be difficult during a competitive season. Therefore, the aim of this study was to investigate changes in the power-duration relationship based on peak power output values obtained during racing. Methods: Fourteen highly trained elite U23 cyclists (N=14; mean ± SD age 20.6 ± 1.1 years; body mass 67.7 ± 6.0 kg; height 180.7 ± 5.6 cm; maximum oxygen uptake 73.9 ± 2.0 mL·kg-1 min-1·; maximal aerobic power 443 ± 27 W) completed 3 maximal efforts on their road bike in the pre-competitive period. The efforts lasted 12, 5 and 2 min on a climb of 5-6% gradient, interspersed by a 30-min recovery period after each trial. In a further step 12, 5 and 2 min power outputs were used to calculate critical power and anaerobic work capacity. During the competitive season peak power outputs during efforts lasting 12, 5 and 2 min were used to track changes in the power-duration relationship over three consecutive periods, for the early (February – April), mid (May – July) and late (August – October) season. A repeated-measure ANOVA was used to compare the peak power outputs across the three periods. Results: Mean power output during the 12, 5 and 2 min maximal effort trials were 379 ± 23, 420 ± 7 and 505 ± 33 W, respectively, resulting in a critical power of 352 ± 24 W (see Graph 1).   Graph 1: Mean power outputs of the pre - season Critical Power Test The 2 min peak power outputs over the three consecutive periods were 484 ± 54, 515 ± 35 and 518 ± 40 W, with significant differences between the first and third periods (p = 0.009). The 5 min peak power outputs were 415 ± 26 W, 441 ± 25 W and 445 ± 24 W, with significant changes between the first and second (p = 0.012) as well as first and third (p = 0.002) periods. Peak power outputs for 12 min were 373 ± 32 W, 397 ± 26 W and 405 ± 24 W, with significant differences between the first and second (p = 0.001) as well as the first and third periods (p = 0.001). Critical power values (see Graph 2) during the three consecutive periods were 342 ± 9 W, 360 ± 6 W and 366 ± 6 W, with significant changes between the first and third periods (p = 0.017).  Graph 2: Variations in Critical power before and during the season Discussion: These findings reveal that variations in peak power outputs during a competitive season have a significant influence on the power-duration relationship. Relatively small changes in peak power outputs could nonetheless be of practical relevance . Indeed, mean improvements of 8.6%, 7.2% and 7.0% in 12, 5 and 2 min peak power outputs from the first to the third period could be quite beneficial for a rider’s and a team’s competition outcomes. In addition, using racing power output data to determine the power-duration relationship as well as parameter estimates of critical power might be a practical means of assessing a cyclist’s fitness. Keywords : cycling, power-duration relationship, critical power

Relationship between preferred saddle height and pedalling kinematics in professional cyclists

Background: Proper saddle height in cycling can improve health, comfort, and performance (Millour et al. 2019). Methods based on knee angle (KA) for saddle height adjustment are frequently employed (Ferrer-Roca et al. 2011). They are considered accurate because they consider individual differences in thigh, shank, and foot length (Bini and Hume 2016). Ferrer-Roca et al. (2011) advocate KA between 30° and 40° during maximum knee extension while pedalling to prevent injuries. However, this method does not consider ankle angle (AA) which can vary considerably according to the individual pedalling technique (Peveler et al. 2012). Purpose: The purpose of this study was to analyse lower limb joint angle of professional cyclists in their preferred saddle height. The hypothesis was that AA should be taken into consideration for an accurate adjustment of saddle height in cycling. Methods: Seventeen professional cyclists volunteered for this experiment (Mean ± SD: 28 ± 5 years old, 1.80 ± 0.05 m, 70 ± 7 kg). A 1 st step was to optimise cycling cleat position with a ML Cleat® device (Morphologics, Saint-Malo, France) and to adjust saddle and handlebar positioning according to the Morphologics ergonomist advices. Then, all the cyclists have 1 month to validate this position or to modify it according to this comfort’s feeling. In a 2 nd step, the cyclists performed a submaximal pedalling test of 3 min at 150 W and 80 rpm on their personal road bike which was mounted on an Elite Turno ergometer ® (Elite, Fontaniva, Italy) enabling to control break resistance. To measure KA, AA, and hip angle (HA) during maximum knee extension (Figure 1), markers were placed on the left side of each participant on greater trochanter, lateral femoral epicondyle, lateral malleolus, and 5 th metatarsal head. A high-resolution digital camera (Go Pro Hero 3, San Mateo, California, USA) was positioned at 4 m and perpendicular to the cyclists. Joint angles data of 10 consecutive pedalling cycles were analysed using kinematic analysis software (Kinovea V0.8.24). A correction of parallax and a correction of distortion were made with this software. Results: The results showed that the means of KA, AA, and HA were 38.0 ± 4.5°, 124.7 ± 5.2°, and 59.2 ± 3.8°, respectively. Although this mean of KA was in the range of 30°-40°, we can observe a large discrepancy between the cyclists and 5 of them had a KA outside the optimal range advocated by Ferrer-Rocca et al. (2011). Figure 2 shows that KA was positively correlated to AA (r = 0.57, p<0.01) but negatively to HA (r = 0.73, p<0.01). Discussion: Our results suggest that professional cyclists can exhibit different pedalling kinematic patterns. Athletes with higher KA present lower HA and important plantarflexion during maximum knee extension. Conversely, athletes with lower KA exhibit higher HA and large dorsiflexion during maximum knee extension. These results are in accordance with Ryan and Gregor (1992) who showed a strong inter-subject variability in pedalling kinematics of well-trained cyclists. Peveler et al. (2012) suggested that optimisation of the cycling position must take into account individual anthropometry as well as pedalling technique, and notably the foot orientation during pedalling. Cyclists who pedal with an important plantarflexion during maximum knee extension may use higher KA than those pedalling with a large dorsiflexion. Conclusion: This study suggests that saddle height adjustment optimisation should take into consideration each rider's pedalling technique, notably foot orientation, and that KA outside optimal Ferrer-Roca range is not necessarily related to a poor saddle height adjustment. Acknowledgements: MorphoLogics Company and Team Arkea Samsic.

NORC 관점에서 본 서울시 노인밀집 아파트의 주거환경 실태조사 : 노원구와 강남구지역의 아파트를 중심으로

This study aims to examine the physical housing environment status from the perspective of NORC in apartment buildings selected as the potential naturally occurring retirement communities. A total of 22 apartment complexes were investigated on-site and photographed at the same time. The survey details are apartment complex size, unit size, floor plan type, housing price, location conditions, neighborhood facilities, universal design application, security, health-related facilities, and elderly-related facilities. The results of the study are as follows. Most of the apartment complexes were aged apartments with 20 years old, with an average area of 46-85 m2. Most of the location conditions were close to subway stations and public transportation stops. Health-related facilities such as walking trails, hiking trails, gardens and flower beds in the complex were well constructed, and a senior welfare center, day care center, and social welfare center were located near the complex. The characteristics of the physical environment that should be supplemented in order to convert the apartment complexes of senior citizens into a healthy environment were found to be the formation of a universal design environment in the complex, the securing of parking spaces, the creation of a pedestrian and bicycle road environment, and the readjustment of various company systems.

限局性脳梁血腫を伴った外傷性脳損傷の経過中にparoxysmal sympathetic hyperactivityを呈した1例(Paroxysmal sympathetic hyperactivity during follow–up for traumatic brain injury with hematoma localized in the corpus callosum: a case report)

要旨 paroxysmal sympathetic hyperactivity（PSH）は重症頭部外傷，低酸素脳症などに起こり，交感神経系が発作性に過活動になる病態である。また，鈍的頭部外傷による限局した脳梁血腫は稀有であるが，その経過においてPSHを呈した症例は我々の知る限りでは報告されていない。症例は16歳の男性で，ロードバイクで下り坂を走行中に対向の軽自動車と正面衝突し，救急搬送となった。第3病日の頭部CTにおいて，限局した脳梁血腫が顕在化した。第7病日から間欠的に40℃台の高熱，頻脈，頻呼吸，発汗，全身の震え，瞳孔散大などの交感神経亢進症状が出現した。第9病日より，PSHを疑いガバペンチン投与を開始。交感神経亢進症状は徐々に鎮静化した。その後，意識レベルは改善し，第54病日に独歩退院した。PSHは外傷性脳損傷（traumatic brain injury: TBI）における，集中治療室（intensive care unit: ICU）滞在期間長期化のリスク因子であり，PSHの病態において，大脳深部損傷との関連があるという報告もある。脳梁損傷のような大脳深部損傷に交感神経亢進症状が発作的に出現する場合はPSHを疑い，治療を早期に開始することが予後改善のために重要であり，治療法の1つとして，ガバペンチンが有効である可能性がある。

Acute Soy Supplementation Improves 20-km Time Trial Performance, Power, and Speed.

Isoflavones, a chemical class of phytoestrogens found in soybeans and soy products, may have biological functions similar to estradiol. After binding with ERβ or perhaps independently of estrogen receptors, isoflavones may augment vascular endothelial relaxation, contributing to improved limb blood flow. To determine if acute fermented soy extract supplementation influences 20-km time trial cycling performance and cardiac hemodynamics compared with a placebo. Subjects included 25 cyclists and triathletes (31 ± 8 yr, V˙O2peak: 55.1 ± 8.4 mL·kg·min). Each subject completed a V˙O2peak assessment, familiarization, and two 20-km time trials in randomized order after ingestion of a fermented soy extract supplement or placebo. The fermented soy extract consisted of 30 g powdered supplement in 16 fl. ounces of water. The placebo contained the same quantities of organic cocoa powder and water. Each trial consisted of 60 min of rest, 30 min at 55% Wpeak, and a self-paced 20-km time trial. Soy supplementation elicited a faster time to 20-km completion (-0.22 ± 0.51 min; -13 s), lower average HR (-5 ± 7 bpm), and significantly greater power (7 ± 3 W) and speed (0.42 ± 0.16 km·h) during the last 5 km of the time trial compared with placebo. Analysis of the results by relative fitness level (<57 vs ≥ 57 mL⋅kg⋅min) indicated that those with a higher level of fitness reaped the largest performance improvement alongside a reduced HR (-5 ± 7 bpm). Ingestion of a fermented soy extract supplement improved sprint-distance performance through improvements in both power and speed. For those with great aerobic fitness, soy supplementation may help to decrease cardiac demand alongside performance improvement.

Road bike accidents involving cervical fractures presenting as cardiac arrest: a report of two cases

We present two cases in which elderly male recreational cyclists suffered from cervical fractures and coinciding injuries of the spinal cord that subsequently led to cardiac arrest.Based on reports from eye witnesses and due to the low impact nature of the crashes, the two patients were initially considered as having cardiac arrest before falling of their bikes.The spinal cord injuries triggering cardiac arrest were acknowledged with delay, as the primary eliciting cause was considered cardiac disease in conjunction with all-out exercise. We suggest that increased focus should be made on possible cervical injuries even following low energy crashes in road cycling.

Validity and reproducibility of commercial cycling power meters in hot and cold environmental temperatures

Power meters are a training tool used to help cyclists improve performance by objectively monitoring intensity. Some power meters are well established and validated, whereas others are relatively new. Most power meters have been tested for validity and reliability in laboratory and field settings of similar conditions; however, the reproducibility of these power meters across different temperatures has not been established. To examine the potential differences of the CompuTrainer, PowerTap, Stages, and Vector power meters in hot and cold compared to a room temperature environment. Recreationally trained male (n=7) and female (n=3) participants each completed three incremental cycling trials in hot (33°C), cold (7°C), or room temperature (RT, 20°C) conditions. The power meters were placed on a standard road bicycle and power output was logged and recorded. The CompuTrainer was higher in the room temperature trial compared to the cold and the hot, but not between the hot and cold trial. The PowerTap was not different in RT and cold, but was lower in hot compared to RT and compared to cold. The Stages was not different between RT and cold, but was lower in the hot compared to RT and compared to cold. The Vector was not different between RT and cold but was lower in the hot compared to RT and compared to cold. These data indicate that environmental temperature may affect the reproducibility of power meters. It is important to recognize the potential differences between temperatures when choosing a power meter.

Characterization of Slag Cement Mortar Containing Nonthermally Treated Dried Red Mud

In this study, a method was suggested to produce dried powder from red mud (RM) sludge with 40%–60% water content without heating. The RM sludge is discharged from the Bayer process, which is used to produce alumina from bauxite ores. Nonthermally treated RM (NTRM) powder was produced by mixing RM sludge (50%), paper sludge ash (PSA, 35%), and high-calcium fly ash (HCFA, 15%). The physicochemical properties of NTRM were investigated by analyzing its water content, X-ray fluorescence spectra, X-ray diffraction patterns, and particle size. Moreover, to examine the applicability of NTRM as a construction material, slag cement mortar in which 20 wt% of the binder was replaced with NTRM was produced, and the compressive strength, porosity, and water absorption rate of the mortar were evaluated. Results indicated that NTRM of acceptable quality was produced when the water content in RM sludge decreased and CaO contained in PSA and HCFA reacted with moisture and formed portlandite. The NTRM-mixed mortar requires further examination in terms of durability because of the increased capillary voids and high water absorption rate, but its compressive strength is sufficient to enable its use in sidewalks, bike roads, and parking lots.

Determining If A Bike-mounted Aerodynamic Sensor Can Detect Changes In Wheel Rolling Resistance During Cycling With Different Tire Pressures Outdoors

Rolling resistance represents a key resistance force to overcome during cycling. This resistance force is calculated as the product of the coefficient of rolling resistance (Crr) and rider+bike system weight. Crr is influenced by a number of factors including tire pressure. Typically, Crr is measured in a laboratory situation but more recently, bike-mounted instruments have been developed that are mounted on a bike to measure Crr in the field. PURPOSE: To determine if a bike-mounted aerodynamic sensor is able to measure changes in Crr with changes in tire pressure while cycling outdoors. METHODS: A cyclist rode a road bike (combined mass 80.45 kg) equipped with an aerodynamic sensor to measure Crr (Aerolab). The bike-mounted sensor measures a number of parameters such as wind speed, global position system (GPS) data, cycling power, and air temperature, for example. Processing algorithms are used to generate Crr. For this experiment, tire pressure was manipulated in a manner that changes in Crr were expected. Specifically, three tire pressures were tested: 100, 70, and 40 PSI. Tire pressure was measured using a custom made valve system connected to a digital pressure gauge (Ashcroft Digital Gauge, 0.05% terminal point accuracy, 0-200 PSI range). The rider completed 2 trials per pressure condition with each trial consisting of a coast-down test. The rider reached a target velocity and then stopped pedaling. Data were recorded for at least 60 seconds for each trial. The rider maintained the same ride position for each trial. Data were processed using custom software to yield Crr per trial using an iterative algorithm that calculates Crr multiple times using different sections of data with corrections for air temperature. The research team member processing data was not aware of the conditions. Crr values were normalized such that the Crr during the 100 psi condition was set to 100%. RESULTS: Relative Crr values were 100±2.7% at 100 psi, 95.7±1.8% at 70 psi, and 119.6±2.7% at 40 psi. CONCLUSIONS: Using a bike-mounted aerodynamic sensor, changes in rolling resistance were detected when tire pressure was manipulated. However, confounding factors that could influence the calculation of Crr include the influence of subtle changes in rider position, yaw angle, and tire temperature, for example.