Effect of an acute β-adrenergic blockade on exercise intensity corresponding to the lactate minimum

β-Adrenoreceptor blockade is reported to impair endurance, power output and work capacity in healthy subjects and patients with hypertension. The purpose of this study was to investigate the effect in eighth athletic males of an acute β-adrenergic blockade with propranolol on their individual power output corresponding to a defined lactate minimum (LM). Eight fit males (cyclist or triathlete) performed a protocol to determine the power output corresponding to their individual LM (defined from an incremental exercise test after a rapidly induced exercise lactic acidosis). This protocol was performed twice in a double-blind randomized order by each athlete first ingesting propranolol (80mg) and in a second trial a placebo, 120 minutes respectively prior to the test sequence. The blood lactate concentration obtained 7 minutes after anaerobic exercise (a Wingate test) was significantly lower after acute β-adrenergic blockade (8.6 ± 1.6mM) than under the placebo condition (11.7 ± 1.6mM). The work rate at the LM was lowered from 215.0 ± 18.6 to 184.0 ± 18.6 watts and heart rate at the LM was reduced from 165 ± 1.5 to 132 ± 2.2 beats/minute as a result of the blockade. There was a non-significant correlation (r = 0.29) between the power output at the LM with and without acute β-adrenergic blockade. In conclusion, since the intensity corresponding to the LM is related to aerobic performance, the results of the present study, are able to explain in part, the reduction in aerobic power output produced during β-adrenergic blockade.

Coronary artery disease is common in asymptomatic patients with signs of myocardial ischemia

BACKGROUND: The incidence of coronary artery disease (CAD) in totally asymptomatic patients with myocardial ischemia during stress testing is unknown. METHODS: 54 patients with asymptomatic myocardial ischemia participated in the Swiss Interventional Study on Silent Ischemia type I (SWISSI I). Asymptomatic myocardial ischemia was verified by bicycle ergometry and stress imaging (echocardiography or scintigraphy). Findings from coronary angiographies in the course of the study constituted the main outcome. RESULTS: Of the 54 study participants, 29 patients (53.7%) underwent coronary angiography. CAD was found in 27 of 29 patients (93.1%). In those 27 patients with CAD, 9 patients (33.3%) suffered from single vessel disease, 9 patients (33.3%) from two vessel disease, and 9 patients (33.3%) from triple vessel disease. Two patients showed left main coronary artery stenosis. CONCLUSION: This study shows a high incidence of relevant CAD among totally asymptomatic patients with myocardial ischemia during stress testing. Previously healthy subjects with exercise-induced ST-segment depression at check-up examinations, even if asymptomatic, should have further diagnostic evaluation.

Building a bicycle suitability map for Coimbra

The adoption of faster modes of transportation (mainly the private car) has changed profoundly the spatial organisation of cities. The increase in distance covered due to increased speed of travel and to urban sprawl leads to an increase in energy consumption, being the transportation sector a huge consumer responsible for 61.5% of total world oil consumption and a global final energy consumption of 31.6% in EU-27 (2007). Due to unsustainable transportation conditions, many cities suffer from congestion and various other traffic problems. Such situations get worse with solutions mostly seen in the development of new infrastructure for motorized modes of transportation, and construction of car parking structures. The bicycle, considered the most efficient among all modes of transportation including walking, is a travel mode that can be adopted in most cities contributing for urban sustainability given the associated environmental, economic and social advantages. In many nations a large number of policy initiatives have focused on discouraging the use of private cars, encouraging the use of sustainable modes of transportation, like public transportation and other forms such as bicycling. Given the importance of developing initiatives that favour the use of bicycle as an urban transportation mode, an analysis of city suitability, including distances and slopes of street network, is crucial in order to help decision-makers to plan the city for bicycle. In this research Geographical Information Systems (GIS) technology was used for this purpose and some results are presented concerning the city of Coimbra.

Mobile cockpit system for enhanced electric bicycle use

This paper presents the project of a mobile cockpit system (MCS) for smartphones, which provides assistance to electric bicycle (EB) cyclists in smart cities' environment. The presented system introduces a mobile application (MCS App) with the goal to provide useful personalized information to the cyclist related to the EB's use, including EB range prediction considering the intended path, management of the cycling effort performed by the cyclist, handling of the battery charging process, and the provisioning of information regarding available public transport. This work also introduces the EB cyclist profile concept, which is based on historical data analysis previously stored in a database and collected from mobile devices' sensors. From the tests performed, the results show the importance of route guidance, taking into account the energy savings. The results also show significant changes on range prediction based on user and route taken. It is important to say that the proposed system can be used for all bicycles in general.

Sex-Specific Equations to Estimate Maximum Oxygen Uptake in Cycle Ergometry

AbstractBackground:Aerobic fitness, assessed by measuring VO2max in maximum cardiopulmonary exercise testing (CPX) or by estimating VO2max through the use of equations in exercise testing, is a predictor of mortality. However, the error resulting from this estimate in a given individual can be high, affecting clinical decisions.Objective:To determine the error of estimate of VO2max in cycle ergometry in a population attending clinical exercise testing laboratories, and to propose sex-specific equations to minimize that error.Methods:This study assessed 1715 adults (18 to 91 years, 68% men) undertaking maximum CPX in a lower limbs cycle ergometer (LLCE) with ramp protocol. The percentage error (E%) between measured VO2max and that estimated from the modified ACSM equation (Lang et al. MSSE, 1992) was calculated. Then, estimation equations were developed: 1) for all the population tested (C-GENERAL); and 2) separately by sex (C-MEN and C-WOMEN).Results:Measured VO2max was higher in men than in WOMEN: -29.4 ± 10.5 and 24.2 ± 9.2 mL.(kg.min)-1 (p < 0.01). The equations for estimating VO2max [in mL.(kg.min)-1] were: C-GENERAL = [final workload (W)/body weight (kg)] x 10.483 + 7; C-MEN = [final workload (W)/body weight (kg)] x 10.791 + 7; and C-WOMEN = [final workload (W)/body weight (kg)] x 9.820 + 7. The E% for MEN was: -3.4 ± 13.4% (modified ACSM); 1.2 ± 13.2% (C-GENERAL); and -0.9 ± 13.4% (C-MEN) (p < 0.01). For WOMEN: -14.7 ± 17.4% (modified ACSM); -6.3 ± 16.5% (C-GENERAL); and -1.7 ± 16.2% (C-WOMEN) (p < 0.01).Conclusion:The error of estimate of VO2max by use of sex-specific equations was reduced, but not eliminated, in exercise tests on LLCE.

Iowa 2015-2016 Bicycle Map, 2015

Iowa has more than 1,800 miles of beautiful trails available for a variety of uses, including bicycling, hiking/running, skating, equestrian use, cross-country skiing, snowmobiling, and photography/nature study. This map lists and highlights 60 trails of 5 miles length or great. It also indicates where shorter trails exist. This record contains PDFs of the full front and back of the map. Inset maps of 16 major cities and their trail systems are included in this record.

Photograph - Owls Bicycle Club, 1889

A photograph of the Owls Bicycle Club in the year 1889. The men are in the rear of the Watson memorial with St. Joseph's convent/orphanage and St. Catharines Cathedral in the background. There are 21 men on bicycle including Stanley G. Smith (second row, fourth from the left).

Influences of infrastructure and attitudes to health on value of travel time savings in bicycle journeys

In this paper we investigate how attitudes to health and exercise in connection with cycling influence the estimation of values of travel time savings in different kinds of bicycle environments (mixed traffic, bicycle lane in the road way, bicycle path next to the road, and bicycle path not in connection with the road). The results, based on two Swedish stated choice studies, suggest that the values of travel time savings are lower when cycling in better conditions. Surprisingly, the respondents do not consider cycling on a path next to the road worse than cycling on a path not in connection to the road, indicating that they do not take traffic noise and air pollution into account in their decision to cycle. No difference can be found between cycling on a road way (mixed traffic) and cycling in a bicycle lane in the road way. The results also indicate that respondents that include health aspects in their choice to cycle have lower value of travel time savings for cycling than respondents that state that health aspects are of less importance, at least when cycling on a bicycle path. The appraisals of travel time savings regarding cycling also differ a lot depending on the respondents’ alternative travel mode. The individuals who stated that they will take the car if they do not cycle have a much higher valuation of travel time savings than the persons stating public transport as the main alternative to cycling.

Indexes of power and aerobic capacity obtained in cycle ergometry and treadmill running: comparisons between sedentary, runners, cyclists and triathletes

The objectives of this study were: a) to determine, in a cross-sectional manner, the effect of aerobic training on the peak oxygen uptake, the intensity at O2peak and the anaerobic threshold (AnT) during running and cycling; and b) to verify if the transference of the training effects are dependent on the analized type of exercise or physiological index. Eleven untrained males (UN), nine endurance cyclists (EC), seven endurance runners (ER), and nine triathletes (TR) were submitted, on separate days, to incremental tests until voluntary exhaustion on a mechanical braked cycle ergometer and on a treadmill. The values of O2peak (ml.kg-1.min-1) obtained in running and cycle ergometer (ER = 68.8 ± 6.3 and 62.0 ± 5.0; EC = 60.5 ± 8.0 and 67.6 ± 7.6; TR = 64.5 ± 4.8 and 61.0 ± 4.1; UN = 43.5 ± 7.0 and 36.7 ± 5.6; respectively) were higher in the group that presented specific training in the modality. The UN group presented the lower values of O2peak, regardless of the type of exercise. This same behavior was observed for the AnT (ml.kg-1.min-1) determined in running and cycle ergometer (ER = 56.8 ± 6.9 and 44.8 ± 5.7; EC = 51.2 ± 5.2 and 57.6 ± 7.1; TR = 56.5 ± 5.1 and 49.0 ± 4.8; UN = 33.2 ± 4.2 and 22.6 ± 3.7; respectively). It can be concluded that the transference of the training effects seems to be only partial, independently of the index (O2peak, IO2peak or AnT) or exercise type (running or cycling). In relation to the indices, the specificity of training seems to be less present in the O2peak than in the IO2peak and the AnT.

Automated Analysis Methods for the Assessment of Bicycle Infrastructure and Demand

A first phase of the research activity has been related to the study of the state of art of the infrastructures for cycling, bicycle use and methods for evaluation. In this part, the candidate has studied the "bicycle system" in countries with high bicycle use and in particular in the Netherlands. Has been carried out an evaluation of the questionnaires of the survey conducted within the European project BICY on mobility in general in 13 cities of the participating countries. The questionnaire was designed, tested and implemented, and was later validated by a test in Bologna. The results were corrected with information on demographic situation and compared with official data. The cycling infrastructure analysis was conducted on the basis of information from the OpenStreetMap database. The activity consisted in programming algorithms in Python that allow to extract data from the database infrastructure for a region, to sort and filter cycling infrastructure calculating some attributes, such as the length of the arcs paths. The results obtained were compared with official data where available. The structure of the thesis is as follows: 1. Introduction: description of the state of cycling in several advanced countries, description of methods of analysis and their importance to implement appropriate policies for cycling. Supply and demand of bicycle infrastructures. 2. Survey on mobility: it gives details of the investigation developed and the method of evaluation. The results obtained are presented and compared with official data. 3. Analysis cycling infrastructure based on information from the database of OpenStreetMap: describes the methods and algorithms developed during the PhD. The results obtained by the algorithms are compared with official data. 4. Discussion: The above results are discussed and compared. In particular the cycle demand is compared with the length of cycle networks within a city. 5. Conclusions