Search

Acute exacerbations of chronic obstructive pulmonary disease (AECOPD) are the major reason for COPD hospitalization and increased risk for readmissions. The organizational structure of Austrian hospitals provides the opportunity to investigate the impact of specialized respiratory care compared to general care on adherence to guidelines and readmission in AECOPD.The data from the European COPD audit, a prospective observational non-interventional cohort trial were analyzed. In total, 823 patients admitted due to AECOPD in 26 hospitals (specialized respiratory care vs. general care) within Austria were included. Patients characteristics and outcomes (length of stay, readmission rate, and mortality) were analyzed in relation to hospital resources (personnel and equipment) and adherence to international guidelines.Patients admitted to general care had more comorbidities (Charlson comorbidity index: 2.6 ± 1.7 vs. 2.0 ± 1.4; p 0.05) and a shorter length of stay (10.7 ± 7.8 days vs. 12.0 ± 10.2 days; p 0.05). Patients admitted to specialized respiratory care more often underwent blood gas analysis and non-invasive ventilation (98.4% vs. 81.5% and 68.6% vs. 26.7%, p 0.01; respectively). In multivariate analysis, the risk for AECOPD readmission was lower (odds ratio, OR 0.72 [0.51;0.91]; p 0.05) in patients admitted to specialized respiratory care.A greater adherence to COPD guidelines with respect to blood gas analysis and non-invasive ventilation and decreased AECOPD readmission risk was observed for patients admitted to specialized respiratory care. Adherence to guidelines may have the potential to decrease COPD readmission rates.

Functional impairment caused by chronic obstructive pulmonary disease (COPD) impacts on activities of daily living and quality of life. Indeed, patients’ submaximal exercise capacity is of crucial importance. It was the aim of this study to investigate the effects of an exercise training intervention with and without supplemental oxygen on submaximal exercise performance. This is a secondary analysis of a randomized, controlled, double‐blind, crossover trial. 29 COPD patients (63.5 ± 5.9 years; FEV1 46.4 ± 8.6%) completed two consecutive 6‐week periods of high‐intensity interval cycling and strength training, which was performed three times/week with either supplemental oxygen or medical air (10 L/min). Submaximal exercise capacity as well as the cardiocirculatory, ventilatory, and metabolic response were evaluated at isotime (point of termination in the shortest cardiopulmonary exercise test), at physical work capacity at 110 bpm of heart rate (PWC 110), at the anaerobic threshold (AT), and at the lactate‐2 mmol/L threshold. After 12 weeks of exercise training, patients improved in exercise tolerance, shown by decreased cardiocirculatory (heart rate, blood pressure) and metabolic (respiratory exchange ratio, lactate) effort at isotime; ventilatory response was not affected. Submaximal exercise capacity was improved at PWC 110, AT and the lactate‐2 mmol/L threshold, respectively. Although supplemental oxygen seems to affect patients’ work rate at AT and the lactate‐2 mmol/L threshold, no other significant effects were found. The improved submaximal exercise capacity and tolerance might counteract patients’ functional impairment. Although cardiovascular and metabolic training adaptations were shown, ventilatory efficiency remained essentially unchanged. The impact of supplemental oxygen seems less important on submaximal training effects.

Background Exercise training is a cornerstone of the treatment of chronic obstructive pulmonary disease (COPD) in all disease stages. Data about the training effects with supplemental oxygen in nonhypoxemic patients remains inconclusive. In this study we set out to investigate the training and oxygen effects on inflammatory markers, vascular function, and endothelial progenitor cells in this population of increased cardiovascular risk. Methods In this prospective, randomized, double-blind, crossover study, 29 patients with nonhypoxemic COPD performed combined endurance and strength training 3 times a week while breathing medical air or supplemental oxygen for the first 6-week period, and were then reallocated to the opposite gas for the following 6 weeks. Exercise capacity, inflammatory biomarkers, endothelial function (peripheral arterial tone analysis), and endothelial progenitor cells were assessed. Data were also analyzed for a subgroup with endothelial dysfunction (reactive hyperemia index Results Following 12 weeks of exercise training, patients demonstrated a significant improvement of peak work rate and an associated decrease of blood fibrinogen and leptin. Eosinophils were found significantly reduced after exercise training in patients with endothelial dysfunction. In this subgroup, peripheral arterial tone analysis revealed a significant improvement of reactive hyperemia index. Generally, late endothelial progenitor cells were found significantly reduced after the exercise training intervention. Supplemental oxygen during training positively influenced the effect on exercise capacity without impact on inflammation and endothelial function. Conclusions This is the first randomized controlled trial in patients with COPD to show beneficial effects of exercise training not only on exercise capacity, but also on systemic/eosinophilic inflammation and endothelial dysfunction.

Engaging in physical exercise and sports is a common part of the daily life of young people and adults. For subjects and athletes with cardiovascular diseases it is fundamental to evaluate whether the clinical conditions are appropriate to come back to competition. Although the safest possible return-to-play must be determined by the physicians in charge, even the society, coaches, sponsors, or relatives could influence this crucial decision. Unfortunately, detailed guidelines regarding the correct approach for each specific pathology are lacking or heterogeneous. Thus, a general approach concerning when to restart physical activity after cardiovascular diseases is here provided, considering different general and individual issues. Furthermore, some of the most frequent cardiovascular diseases among young athletes were specifically analyzed, discussing a proper return-to-play. Although physical activity is useful in the prevention and treatment of different cardiovascular diseases, the return-to-play must be approached carefully and an adequate collaboration between physicians, athletes, and third parties must be guaranteed because safety comes first, and follow-up is needed.

Physical activity increases life expectancy and has a strong impact on the prevention and treatment of different chronic diseases and risk factors. Thus, physical exercise and sport should a priori not be considered as potentially harmful but rather as essential for people, society and the healthcare system. However, intensive exercise training and competitive sports participation, in predisposed individuals, is associated with a higher risk of incidental adverse cardiovascular events, including sudden cardiac death (SCD). SCD in sports is a rare but devastating event, causing a strong emotional and social impact within the community, especially when young apparently healthy athletes are involved. Almost invariably, the victims carry an underlying, frequently undiagnosed, predisposing and potentially detectable cardiovascular disease. In young athletes ( 35 years of age), almost 80% of these tragic events can be ascribed to latent coronary artery disease. Accordingly, the aim of a medical pre-participation evaluation is to detect potentially life-threatening conditions, which, if timely identified, can be appropriately managed through lifestyle modifications, physical activity adaptations, pharmacotherapy and/or implantable cardioverter defibrillators (ICDs), thereby minimizing the risk of major cardiovascular adverse events. Thus, before participation in sports, every athlete may benefit from a cardiovascular screening, which in baseline consists of a focused family and personal medical history, physical examination and, according to the European Society of Cardiology Guidelines, a resting ECG. Moreover, an additional incremental exercise testing might be useful, particularly in subjects performing high-intensity exercise or those with higher cardiovascular risk. Pre-competition evaluation for safe sport activities has diverse ethical and socio-economic implications, which is the reason why medical guidelines and recommendations differ widely between countries. Despite the most accurate pre-participation evaluation, SCD on the playing field may still happen. Therefore, exercise professionals who supervise exercise and fitness programs should engage in training of basic and/or advanced cardiac life support and other emergency procedures. Moreover, appropriate resuscitation equipment and an automated external defibrillator (AED) should always be promptly available.

Physical exercise training is an evidence-based treatment in chronic obstructive pulmonary disease, and patients' peak work rate is associated with reduced chronic obstructive pulmonary disease mortality. We assessed whether supplemental oxygen during exercise training in nonhypoxemic patients with chronic obstructive pulmonary disease might lead to superior training outcomes, including improved peak work rate.This was a randomized, double-blind, controlled, crossover trial. Twenty-nine patients with chronic obstructive pulmonary disease (aged 63.5 ± 5.9 years; forced expiratory volume in 1 second percent predicted, 46.4 ± 8.6) completed 2 consecutive 6-week periods of endurance and strength training with progressive intensity, which was performed 3 times per week with supplemental oxygen or compressed medical air (flow via nasal cannula: 10 L/min). Each session of electrocardiography-controlled interval cycling lasted 31 minutes and consisted of a warm-up, 7 cycles of 1-minute intervals at 70% to 80% of peak work rate alternating with 2 minutes of active recovery, and final cooldown. Thereafter, patients completed 8 strength-training exercises of 1 set each with 8 to 15 repetitions to failure. Change in peak work rate was the primary study end point.The increase in peak work rate was more than twice as high when patients exercised with supplemental oxygen compared with medical air (0.16 ± 0.02 W/kg vs 0.07 ± 0.02 W/kg; P.001), which was consistent with all other secondary study end points related to exercise capacity. The impact of oxygen on peak work rate was 39.1% of the overall training effect, whereas it had no influence on strength gain (P.1 for all exercises).We report that supplemental oxygen in nonhypoxemic chronic obstructive pulmonary disease doubled the effect of endurance training but had no effect on strength gain.

Background: The horsepower not only of doctors&rsquo, cars correlates with personal income and social status. However, no clear relationship has previously been described between the horsepower of doctors&rsquo, cars and cardiovascular health or sexual dysfunction and/or satisfaction. Objective: Cross-sectional online survey to evaluate associations between self-reported horsepower of physicians&rsquo, cars and health aspects. Methods: Of 1877 physicians from the two University-Hospitals in Austria that were asked to participate in the study, 363 (37.7 &plusmn, 8.0 years, 208 (57.3%) men) were included into the final analysis. Results: Physicians that own a car with a stronger engine were significantly older, were more often male, had more often a leading position, had a higher monthly income (all p &lt, 0.001), had a higher scientific output (p = 0.030), and had hypercholesteremia more often (p = 0.009). They also tended to have a higher body mass index (p = 0.088), reported a higher maximum weight in previous years (p = 0.004) and less often reported regular healthy commuting to and from work (p = 0.010). No significant associations were found for self-reported physical fitness, smoking status, and arterial hypertension. In addition, sexual satisfaction and sexual dysfunction were also not related to horsepower in the whole population and the male subgroup. The findings essentially persisted after controlling for age. Conclusion: The horsepower of Austrian physicians&rsquo, cars correlates with senior position and increased cardiovascular risk. However, our data shows no relationship between sexual dysfunction or lack of sexual satisfaction and the horsepower of doctors&rsquo, cars.

Whereas exercise training is key in the management of patients with cardiovascular disease (CVD) risk (obesity, diabetes, dyslipidaemia, hypertension), clinicians experience difficulties in how to optimally prescribe exercise in patients with different CVD risk factors. Therefore, a consensus statement for state-of-the-art exercise prescription in patients with combinations of CVD risk factors as integrated into a digital training and decision support system (the EXercise Prescription in Everyday practice & Rehabilitative Training (EXPERT) tool) needed to be established. EXPERT working group members systematically reviewed the literature for meta-analyses, systematic reviews and/or clinical studies addressing exercise prescriptions in specific CVD risk factors and formulated exercise recommendations (exercise training intensity, frequency, volume and type, session and programme duration) and exercise safety precautions, for obesity, arterial hypertension, type 1 and 2 diabetes, and dyslipidaemia. The impact of physical fitness, CVD risk altering medications and adverse events during exercise testing was further taken into account to fine-tune this exercise prescription. An algorithm, supported by the interactive EXPERT tool, was developed by Hasselt University based on these data. Specific exercise recommendations were formulated with the aim to decrease adipose tissue mass, improve glycaemic control and blood lipid profile, and lower blood pressure. The impact of medications to improve CVD risk, adverse events during exercise testing and physical fitness was also taken into account. Simulations were made of how the EXPERT tool provides exercise prescriptions according to the variables provided. In this paper, state-of-the-art exercise prescription to patients with combinations of CVD risk factors is formulated, and it is shown how the EXPERT tool may assist clinicians. This contributes to an appropriately tailored exercise regimen for every CVD risk patient. ispartof: SPORTS MEDICINE vol:48 issue:8 pages:1781-1797 ispartof: location:New Zealand status: published

Increased inter-arm systolic blood pressure difference (ΔPsys) has been associated with cardiovascular (CV) disease in elderly patients with CV risk factors. However, its significance in healthy subjects is unclear. To determine the relationship between ΔPsys, the individual level of physical activity and the global CV risk in apparently healthy adults. Systolic blood pressure was measured in both arms in 400 subjects aged 46.5 ± 12.2 years, using a simultaneous oscillometric device (WatchBP Office, Microlife, Widnau, Switzerland). In the subjects with ΔPsys ≥ 10 mmHg (Cases n = 20) and in a Control group (20 subjects without ΔPsys ≥ 10 mmHg), another simultaneous measurement was repeated during a second visit. The physical activity level was assessed via the International Physical Activity Questionnaire-Short Form (IPAQ-SF), the ankle brachial pressure index (ABPI) with a photoplethysmographic method (Angioflow-Microlab, Padova, Italy) and the CV risk via the Framingham Risk Score (FRS). The prevalence of ΔPsys ≥ 10 mmHg in the whole population was 5% (95% CI 3.24–8.01%). Cases and Controls were comparable in gender, age, and BMI. ΔPsys ≥ 10 mmHg was only confirmed in 17.6% of the Cases. No statistically significant differences were found between groups for IPAQ-SF, ABPI, or FRS. The prevalence of ΔPsys ≥ 10 mmHg in this population was only slightly lower than what observed in older, hypertensive or diabetic patients. Cases and Controls did not differ in physical activity level, ankle brachial pressure index and CV risk. However, low test–retest reliability might limit the use of ΔPsys as a reliable marker for CV screening in this population.

This study investigated whether different breathing conditions during exercise testing will influence measures of exercise capacity commonly used for training prescription in chronic obstructive pulmonary disease. Twenty-seven patients with chronic obstructive pulmonary disease (forced expiratory volume in 1 sec = 45.6 [9.4]%) performed three maximal exercise tests within 8 days, but at least 48 hrs apart. Subjects were thereby breathing either room air through a tightly fitting face mask like during any cardiopulmonary exercise test (MASK), room air without mask (No-MASK), or 10 l/min of oxygen via nasal cannula (No-MASK + O2). Cycling protocols were identical for all tests (start = 20 watts, increment = 10 males/5 females watts/min). Maximal work rate (90.4 [33.8], 100.3 [34.8], 107.4 [35.9] watts, P < 0.001) and blood lactate at exhaustion (4.3 [1.5], 5.2 [1.6], 5.0 [1.4] mmol/l, P < 0.001) were lowest for MASK when compared with No-MASK and No-MASK + O2, respectively, whereas maximal heart rate did not differ significantly. Submaximal exertion (Borg rating of perceived exertion = 12-14) was perceived at lower intensity (P = 0.008), but higher heart rate (P = 0.005) when MASK was compared with No-MASK and No-MASK + O2. Different breathing conditions during exercise testing resulted in an 18.8% difference in maximal work rate, likely causing underdosing or overdosing of exercise in chronic obstructive pulmonary disease. Face masks reduced whereas supplemental oxygen increased patients' exercise capacity. For accurate prescription of exercise in chronic obstructive pulmonary disease, breathing conditions during testing should closely match training conditions.

Background Exercise rehabilitation is highly recommended by current guidelines on prevention of cardiovascular disease, but its implementation is still poor. Many clinicians experience difficulties in prescribing exercise in the presence of different concomitant cardiovascular diseases and risk factors within the same patient. It was aimed to develop a digital training and decision support system for exercise prescription in cardiovascular disease patients in clinical practice: the European Association of Preventive Cardiology Exercise Prescription in Everyday Practice and Rehabilitative Training (EXPERT) tool. Methods EXPERT working group members were requested to define (a) diagnostic criteria for specific cardiovascular diseases, cardiovascular disease risk factors, and other chronic non-cardiovascular conditions, (b) primary goals of exercise intervention, (c) disease-specific prescription of exercise training (intensity, frequency, volume, type, session and programme duration), and (d) exercise training safety advices. The impact of exercise tolerance, common cardiovascular medications and adverse events during exercise testing were further taken into account for optimized exercise prescription. Results Exercise training recommendations and safety advices were formulated for 10 cardiovascular diseases, five cardiovascular disease risk factors (type 1 and 2 diabetes, obesity, hypertension, hypercholesterolaemia), and three common chronic non-cardiovascular conditions (lung and renal failure and sarcopaenia), but also accounted for baseline exercise tolerance, common cardiovascular medications and occurrence of adverse events during exercise testing. An algorithm, supported by an interactive tool, was constructed based on these data. This training and decision support system automatically provides an exercise prescription according to the variables provided. Conclusion This digital training and decision support system may contribute in overcoming barriers in exercise implementation in common cardiovascular diseases. The author(s) disclosed receipt of the following financial support for the research, authorship and/or publication of this article: The realisation of the proof of concept of the EXPERT tool was supported by a UHasselt Industrial Research Fund (IOF) proof of concept (PoC) project.

Background Regular physical activity promotes physical and mental health. Psychiatric patients are prone to a sedentary lifestyle, and accumulating evidence has identified physical activity as a supplemental treatment option. Methods This prospective, randomized, crossover study evaluated the effects of hiking in high-risk suicidal patients (n = 20) who performed 9 weeks of hiking (2-3 hikes/week, 2-2.5 hours each) and a 9-week control period. Results All patients participated in the required 2 hikes per week and thus showed a compliance of 100%. Regular hiking led to significant improvement in maximal exercise capacity (hiking period Δ: +18.82 ± 0.99 watt, P P = .134) and in aerobic capability at 70% of the individual heart rate reserve (hiking period Δ: +8.47 ± 2.22 watt; P = .010; control period: P = .183). Cytokines, associated previously with suicidality (tumor necrosis factor-α, interleukin-6, S100), remained essentially unchanged. Conclusions Hiking is an effective and safe form of exercise training even in high-risk suicidal patients. It leads to a significant improvement in maximal exercise capacity and aerobic capability without concomitant deterioration of markers of suicidality. Offering this popular mode of exercise to these patients might help them to adopt a physically more active lifestyle.

The purpose of this study was to examine the incidence and mechanisms of acute injuries in the sport of fistball. No scientific studies on injury characteristics have yet been conducted in this traditional sport game. The study was conducted prospectively over the course of 12 months. During a total of 40.308 h of sport-specific exposure, 240 players reported 492 injuries, representing an overall injury rate of 12.2 injuries/1000 h of exposure. Most injuries were classified as bagatelle injuries (67.8%). The majority of the injuries were located in the knee (23.5%) followed by the elbow (11.9%) and the hip (11.5%). Ankle injuries resulted in the longest impairment from sports participation. The most common types of injury were abrasions (38.2%), contusions (21.1%), distortions (7.5%) and muscle strains (6.9%). Wrong or insufficient equipment (15.0%) was the most commonly mentioned causes of injury. The data indicate that the injury risk in fistball is rather high; however, the sport should not be considered a high-risk sport because most of the injuries are slight and do not prevent the players from training or competition. Injury prevention strategies should include the development of fistball-specific protective equipment with focus on the knee and elbow joint.

OBJECTIVE: To describe rates, patterns, and causes of acute injuries in an increasingly popular outdoor sport. DESIGN: Prospective cohort study. SETTING: One winter season ranging from November 2011 to March 2011. PARTICIPANTS: Seventy ice climbers from 13 different countries and various performance levels. MAIN OUTCOME MEASURES: Participants were asked to complete a monthly Internet-based survey regarding their completed hours of training and competitions and eventual sustained injuries. RESULTS: During 4275 hours of ice climbing, 42 injuries occurred, of which 81.0% were defined as mild, 16.6% as moderate, and 2.4% as severe. The calculated injury rate was 9.8 injuries per 1000 hours of sports exposure. Intermediate ice climbers had a significantly higher injury risk compared with advanced ice climbers (odds ratio, 2.55; 95% confidence intervals, 1.17-5.54; P = 0.018). About 73.8% of all injuries occurred on a frozen waterfall, icicles, or icefalls, whereas 4.8% occurred on artificial ice walls. The head was the most injured body part (47.6%), followed by the knee (14.3%) and the shoulder (11.9%). The most common types of injuries were abrasions (38.1%), contusions (35.7%), and joint sprains (7.1%). Falling ice was the main circumstance leading to injury (59.5%). All athletes with a head injury wore a helmet; however, only 35.0% mentioned they used protective goggles. CONCLUSION: Ice climbing is a sport with moderate risk for injury with most of the reported injuries being of minor severity. However, severe and fatal injuries, although less common, also occur. Advanced ice climbers with greater experience and skill level have a lower overall injury risk. Language: en

INTRODUCTION: Freestyle Motocross (FMX) is an emerging extreme sport in which motocross riders perform risky jumps and tricks, which are graded by judges for their degree of difficulty, originality, and style. To this date, injury, patterns and causes in Freestyle Motocross have not been determined. METHODS: Over the time period from January 2006 to December 2012, 19 professional FMX riders of an internationally active FMX team were retrospectively surveyed by means of a questionnaire and questionnaire-based interviews regarding injuries sustained during training, shows, or competition. The questionnaire collected information regarding injury type, circumstances, causes, and treatment. In addition, general information was obtained on body dimensions, experience, training, and equipment used. RESULTS: A total of 54 accidents resulting in 78 severe injuries were registered. The most common types of injuries were fractures (66.6 %), ligament ruptures (7.7 %), and contusions (6.4 %). Most frequently affected body regions were foot/ankle (20.5 %), shoulder (12.8 %), and back (10.3 %). The Backflip was the trick during which most of the injuries occurred (35.2 %). Incorrect execution of jumps (25.9 %) was the leading cause of accidents. CONCLUSION: Based on our data, FMX is a high-risk sport. To avoid injuries, ramps, motorcycles, and equipment should be in the best possible shape and the athletes themselves in good physical and mental condition. Attendance of medical staff during FMX activity is advised at all time. Language: de

Objective: The following crossover pilot study attempts to prove the effects of endurance training through mountain hiking in high-risk suicide patients. Method: Participants (n = 20) having attempted suicide at least once and clinically diagnosed with hopelessness were randomly distributed among two groups. Group 1 (n = 10) began with a 9-week hiking phase followed by a 9-week control phase. Group 2 (n = 10) worked vice versa. Assessments included the Beck Hopelessness Scale (BHS), Beck Depression Inventory (BDI), Beck Scale of Suicide Ideation (BSI), and maximum physical endurance. Results: Ten participants of Group 1 and seven participants of Group 2 completed the study. A comparison between conditions showed that, in the hiking phase, there was a significant decrease in hopelessness (P Language: en

Evidence-based medicine promotes the current best evidence from clinical trials to guide decisions for individual patients. We assessed whether chronic obstructive pulmonary disease (COPD) patients included in exercise training studies and pharmacologic trials match those from a non-selected COPD target population sample. Exercise training studies were identified in a literature search. Towards a Revolution in COPD Health (TORCH) and Understanding Potential Long-Term Impacts on Function with Tiotropium (UPLIFT) were chosen to represent pharmacologic trials. Burden of Obstructive Lung Disease (BOLD) data were used to characterize target COPD population (BOLD target), defined as the presence of dyspnea (modified Medical Research Council ≥2) and non-reversible airway obstruction (post-bronchodilator FEV1/FVC ≤0.7 and FEV1% predicted ≤70 %). Overall 240 exercise training studies with 13,901, TORCH and UPLIFT with 12,105, and BOLD with 16,218 participants were evaluated. Males were overrepresented in exercise training studies (67.5 %) and pharmacologic trials (TORCH 75.8 %; UPLIFT 74.6 %), whereas in BOLD target 55.8 % were males (p

Background Downhill mountain biking (DMB) has become an increasingly popular extreme sport in the last few years with high velocities and bold manoeuvres. The goal of this study was to provide information on the pattern and causes of injuries in order to provide starting points for injury prevention measures. Methods We performed a monthly e-mail-based prospective survey of 249 riders over one summer season ranging from April until September 2011. Results A total of 494 injuries occurred during the 29 401 h of downhill exposure recorded, of these 65% were mild, 22% moderate and 13% severe, of which 41% led to a total restriction greater than 28 days. The calculated overall injury rate was 16.8 injuries per 1000 h of exposure. For experts it was 17.9 injuries per 1000 h of exposure, which is significantly higher than the 13.4 for professional riders (OR 1.34; 95% CI, 1.02 to 1.75; p=0.03). A significantly higher rate of injury was reported during competition (20 per 1000 h) than during practice (13 per 1000 h) (OR 1.53; 95% CI, 1.16 to 2.01; p=0.0022). The most commonly injured body site was the lower leg (27%) followed by the forearm (25%). Most frequent injury types were abrasions (64%) and contusions (56%). Main causes of injury reported by the riders were riding errors (72%) and bad trail conditions (31%). Conclusions According to our data DMB can be considered an extreme sport conveying a high risk of serious injury. Strategies of injury prevention should focus on improvements in riders’ technique, checking of local trail conditions and protective equipment design.

Human skeletal muscles consist of different fibre types: slow fibres (slow twitch or type I) containing the myosin heavy chain isoform (MHC)-I and fast fibres (fast twitch or type II) containing MHC-IIa (type IIA) or MHC-IId (type IID). The following order of decreasing kinetics is known: type IID > type IIA >> type I. This order is especially based on the kinetics of stretch activation, which is the most discriminative property among fibre types. In this study we tested if hybrid fibres containing both MHC-IIa and MHC-I (type C fibres) provide a transition in kinetics between fast (type IIA) and slow fibres (type I). Our data of stretch activation kinetics suggest that type C fibres, with different ratios of MHC-IIa and MHC-I, do not provide a continuous transition. Instead, a specialized group of slow fibres, which we called “transition fibres”, seems to provide a transition. Apart of their kinetics of stretch activation, which is most close to that of type IIA, the transition fibres are characterized by large cross-sectional areas and low maximal tensions. The molecular cause for the mechanical properties of the transition fibres is unknown. It is possible that the transition fibres contain an unknown slow MHC isoform, which cannot be separated by biochemical methods. Alternatively, or in addition, isoforms of myofibrillar proteins, other than MHC, and posttranslational modifications of myofibrillar proteins could play a role regarding the characteristics of the transition fibres.