Submaximal Performance Research Articles

Additive value of simultaneous cardiopulmonary exercise testing to exercise echocardiography in unexplained dyspnea

Abstract Background In patients with unexplained dyspnea, exercise echocardiography with diastolic stress testing is recommended to diagnose heart failure with preserved ejection fraction (HFpEF). Combined cardiopulmonary exercise testing (CPET) with echocardiography (CPETecho) adds respiratory gas analysis and is thus able to characterize all physiologic abnormalities limiting exercise capacity including cardiac, pulmonary and peripheral causes. Purpose To evaluate the use of CPETecho in patients with unexplained dyspnea compared to exercise echocardiography alone. Methods In this retrospective observational study, we evaluated patients with unexplained dyspnea (normal resting echocardiography and normal lung function) who underwent CPETecho at two university hospitals between July 2021 and November 2023. CPETecho was conducted on a semi-supine bicycle ergometer. At rest, submaximal exercise (heart rate ±100 bpm) and peak exercise echocardiography was performed. Respiratory gases, heart rate, and electrocardiogram were recorded continuously. We evaluated limitations to exercise according to cutoffs in published literature, and compared them to diagnoses obtained via exercise echocardiography values alone with CPET values being blinded. Results We enrolled 124 patients (63% women, mean age 67 ± 12 years). Peak VO2 was 88 ± 19% of the predicted value. CPETecho identified causes for dyspnea in 101 patients (81%), compared to 121 patients (98%) with exercise echocardiography. However, only in 60 out of the 121 patients (50%) exercise echo could provide a ‘certain and complete’ diagnosis. In 37 patients (31%), the correct diagnosis was missed by exercise echo: peripheral or pulmonary limitations, hyperventilation or V/Q mismatch. Additionally, in 19 patients (15%) exercise echo incorrectly diagnosed chronotropic incompetence, left ventricular (LV) systolic dysfunction, or impaired right ventricular (RV) reserve while actually patients had a submaximal performance. Finally, 4 patients (3%) had both missing and uncertain diagnoses. In contrast, CPETecho allowed immediate detection of a submaximal test, ensuring that the identified diagnoses can be considered ‘certain’ (101 patients, 81%). Nineteen patients (15%) had an ‘uncertain’ diagnosis due to a submaximal test, 1 patient (1%) had an uncertain diagnosis despite a maximal test performance, and 3 patients had missing data due to poor image quality (2%). Conclusions In patients with unexplained dyspnea, CPETecho led to more accurate diagnoses compared to exercise echocardiography alone. Exercise echocardiography alone misclassified several patients, primarily due to its incapacity to identify pulmonary or peripheral limitations, and the inability to detect a submaximal test.

Is the Force-Velocity Profile for Free Jumping a Sound Basis for Individualized Jump Training Prescriptions?

Formulating individualized optimized jump training prescriptions based on the force-velocity profile has become popular, but its effectiveness has been contested. Such training programs have opposite effects on 'maximal average force' and 'maximal average shortening velocity', and we set out to investigate which training-induced changes in the neuromuscular system could cause such effects. We used a musculoskeletal simulation model with four body segments and six muscle-tendon actuators to simulate vertical squat jumps with different loads. Independent input was muscle stimulation over time, which was optimized for maximal jump height. We determined the force-velocity profile for a reference model and investigated how it changed when we modified muscle properties and initial postures. We could not reproduce the reported training effects by realistically improving muscle properties (maximal force, shortening velocity and rate of force development) or modifying initial postures of the model. However, the profile was very sensitive to gains in jump height at low-loads but not high loads, or vice versa. Reaching maximal height in force-velocity profile jumps requires skill. We argued that submaximal performance in low-load or high-load jumps caused by lack of skill could be responsible for large imbalances in profiles before training. Differential skill training promoted by the individualized optimized approach could explain quick changes toward a balanced profile. If the success of individualized optimized training studies is explained by selective skill improvements, training effects are unlikely to transfer to other tasks, and individualized optimized training will not be superior to other types of training.

Carbon monoxide supplementation: evaluating its potential to enhance altitude training effects and cycling performance in elite athletes.

Altitude training is a cornerstone for endurance athletes for improving blood variables and performance, with optimal effects observed at ∼2,300-2,500 meters above sea level (m.a.s.l.). However, elite cyclists face challenges such as limited access to such altitudes, inadequate training facilities, and high expenses. To address these issues, a novel method involving daily exposure to carbon monoxide (CO) has been proposed to amplify altitude training adaptations at suboptimal altitudes. Thirty-one male cyclists were assigned to three groups: Live-High Train-High with CO inhalation (LHTHCO), Live-High Train-High (LHTH), and Live-Low Train-Low (LLTL). The LHTHCO group underwent CO inhalation twice daily in the afternoon/evening to elevate carboxyhemoglobin concentration to ∼10%. Hematological variables, in vivo muscle oxidative capacity, and physiological indicators of cycling performance were assessed before and after a 3-week altitude training camp at 2,100 m.a.s.l. LHTHCO demonstrated a larger increase in hemoglobin mass (Hbmass) compared to both LHTH and LLTL. Although there were no statistical differences between LHTHCO and LHTH in submaximal and maximal performance measures, LHTHCO displayed greater improvements in 1-min maximal power output during incremental testing (Wmax), power output at lactate threshold, and maximal oxygen consumption (V̇o2max) compared to LLTL. LHTH demonstrated a larger improvement than LLTL in Wmax and V̇o2max, with no group differences in Hbmass or submaximal measures. Muscle oxidative capacity did not differ between groups. These findings suggest that combining moderate-altitude training with daily CO inhalation promotes hematological adaptations more effectively than moderate altitude alone and enhances cycling performance metrics in cyclists more than sea-level training.NEW & NOTEWORTHY Three weeks of training at moderate altitude with exposure to low doses of CO can significantly enhance hematological adaptations in elite cyclists compared to moderate-altitude training alone. Cycling performance determinants improved more with CO inhalation at moderate altitude compared to sea-level training, whereas there were no differences in submaximal and maximal performance measures compared to moderate-altitude training alone. This study highlights the potential of CO supplementation as an effective adjunct to altitude training regimens.

Effects of 4 weeks of device-induced normobaric intermittent hypoxia/hyperoxia training on the performance of elite cyclists: A pilot study

Introduction & Purpose Classic altitude training and other forms of hypoxia are regularly used in endurance training (Mujika et al., 2019). Due to corona exit restrictions in 2019-2020, device-induced normobaric hypoxia/hyperoxia was suggested as an alternative to classic altitude training. Intermittent hypoxia/hyperoxia training (IHHT) has been studied and used in various forms since the 1940s (Serebrovskaya, 2002) with the advantage to be used at the athlete’s training site (Burtscher, 2005). The aim of this pilot study was to test the effects of a IHHT intervention on aerobic performance, hematological parameters and hypoxia-induced factor-1α (HIF-1α). Method A total of 11 athletes (2 women) from the U23 and elite national squads of the Austrian Cycling Federation completed 16 IHHT units in addition to their normal training program over a period of 4 weeks as part of a randomized cross over intervention study (control – IHHT, IHHT – control). The IHHT units were carried out on a Cellgym CellAir® Gecko Plus device at rest without exercise following a predetermined protocol (Sessions 1-8: 5 min of hypoxia (12.0% oxygen) followed by 3 min of hyperoxia (34.0% oxygen) repeated five times. Sessions 9-16): 6 min of hypoxia (11.0% oxygen) followed by 3 min of hyperoxia (34.0% oxygen). During the 4 weeks of control period, participants should maintain their training schedule. Aerobic performance was determined before and after the intervention by spiroergometry. As secondary outcomes, changes in hematological parameters and protein levels of HIF-1α were determined from venous blood which was processed immediately after collection. Serum was stored at -80 °C until HIF-1 α determination by ELISA technique. Results Eleven out of 13 athletes took part in the pre – post IHHT measurements, but only three of them managed to participate in the measurements planned for the control period, making it impossible to compare the two conditions. Replacement was not possible due to the availability of candidates and the ongoing preparation for the season. After 4 weeks of intervention with 16 IHHT training sessions, no significant changes were observed in performance parameters such as VO2peak, relative VO2max, maximum power (watts) or threshold values (p > 0.05). There were also no significant changes in blood enzymes, lipid and iron metabolism (p > 0.05). However, a tendency towards increased values of haemoglobin (z = 1.738; p = 0.082) and a significant increase of erythrocyte counts (z = 2.193; p = 0.028) were detected. Other haematological parameters and HIF-1α did not change significantly (p > 0.05). Discussion & Conclusion In summary, four weeks of device-induced normobaric IHHT had a modest effect on haematological parameters, but with no detectable transfer to maximal or submaximal endurance performance in highly trained athletes. Although various studies have shown that the difference between normobaric and hypobaric hypoxia exposure is not limited to the partial pressure of oxygen, but Mounier and Brugniaux state that the physiological responses are in fact equivalent (Mounier & Brugniaux, 2012). However, due to the limitations of the competitive setting and the low sample size, the final interpretation of the study remains difficult. References Burtscher, M. (2005). Intermittierende Hypoxie: Höhenvorbereitung, Training, Therapie [Intermittent hypoxia: altitude preparation, training, therapy]. Schweizerische Zeitschrift für Sportmedizin und Sporttraumatologie, 53(2), 61-67. Serebrovskaya, T. V. (2002). Intermittent hypoxia research in the former Soviet Union and the commonwealth of independent states: History and review of the concept and selected applications. High Altitude Medicine & Biology, 3(2), 205-221. https://doi.org/10.1089/15270290260131939 Mounier, R., & Brugniaux, J. V. (2012). Counterpoint: Hypobaric hypoxia does not induce different responses from normobaric hypoxia. Journal of Applied Physiology, 112(10), 1784-1786. https://doi.org/10.1152/japplphysiol.00067.2012a Mujika, I., Sharma, A. P., & Stellingwerff, T. (2019). Contemporary periodization of altitude training for elite endurance athletes: A narrative review. Sports Medicine, 49, 1651-1669. https://doi.org/10.1007/s40279-019-01165-y

The Short Physical Performance Battery does not correlate with daily life gait quality and quantity in community-dwelling older adults with an increased fall risk

Both the Short Physical Performance Battery (SPPB) and daily life gait quality and quantity obtained from wearable sensors are used to measure functional status in older adults. It is generally assumed that they are interrelated and exchangeable, but this has not yet been established. Interchangeability of these measures would pave the way for remote monitoring of functional status. Are the SPPB and daily life gait quality and quantity measures correlated in community-dwelling older adults? The SPPB and gait quality and quantity data of 229 community-dwelling adults of 65 years or older were collected. The SPPB is a combined score of the Three Stage Balance test, Four Meter Walk test, and Five Times Sit to Stand test and ranges from 0 to 12. Participants wore a tri-axial inertial sensor for one week to assess gait quality (e.g. gait stability and smoothness) and quantity (e.g. number of strides). Correlation coefficients between SPPB scores and gait quality and quantity measures were assessed using Spearman's correlation. The median age of the study population was 76.2 years (IQR 72.6-81.0), and 76 % were women (n=175). The median SPPB score was 10 (IQR 8-11). Spearman's correlation coefficients between the SPPB and gait quality and quantity measures were all below 0.3. A possible explanation for the observed weak correlations is that the SPPB reflects one's maximal capacity, while gait quality and quantity reflect the submaximal performance in daily life. The SPPB and gait quality and quantity seem therefore distinct constructs with complementary value, rather than interchangeable. A more comprehensive understanding of functional status might be achieved by combining the SPPB assessment of standardized activities with the evaluation of inertial sensor measurements obtained during daily life activities.

Pre-Exercise Caffeine and Sodium Bicarbonate: Their Effects on Isometric Mid-Thigh Pull Performance in a Crossover, Double-Blind, Placebo-Controlled Study.

Caffeine and sodium bicarbonate are extensively researched ergogenic aids known for their potential to enhance exercise performance. The stimulant properties of caffeine on the central nervous system, coupled with the buffering capacity of sodium bicarbonate, have been associated with improved athletic performance. This has led to investigations of their combined effects on strength. The aim of the present study is to investigate the effect of isolated and combined caffeine and sodium bicarbonate consumption on strength using the isometric mid-thigh pull test (IMTP). Nineteen male college students (age 23.6 ± 1.6 years) participated in this crossover, double-blind, placebo-controlled study. They were exposed to the following conditions: control (no supplement), placebo (20 g maltodextrin), caffeine (6 mg/kg), sodium bicarbonate (0.3 g/kg), and a combination of caffeine and sodium bicarbonate. Supplements and placebo were diluted in water and consumed 60 min prior to the IMTP tests. Two 5 s IMTP trials were performed at 40-60% and 60-80% of One Repetition of Maximum (1RM) with a 60 s rest between. Consumption of caffeine or Caf + NaHCO3 did not significantly change peak IMTP strength values at any intensity (p = 0.110). The peak IMTP values did not show significant differences between conditions or from control condition values (1091 ± 100 N) to Caf (1224 ± 92 N), NaHCO3 (1222 ± 74 N), and Caf ± NaHCO3 (1152 ± 109 N). However, the test of the results of the ANOVA analysis of repeated measures of effect within the caffeine condition was significant for the increase in IMTP relative strength compared to control (p < 0.05). Thus, the IMTP force values increased significantly from control to Caf (p = 0.016) and from Pla to Caf (p = 0.008), but not for other comparisons (p > 0.05). In summary, caffeine supplementation alone, taken 60 min before exercise, positively affects submaximal strength performance. In contrast, sodium bicarbonate, whether taken alone or in combination with caffeine, does not enhance submaximal strength in the IMTP tests.

MUSIC THERAPY AND BACKGROUND MUSIC IN THE PHYSIOTHERAPY OF A PATIENT WITH NORMAL PRESSURE HYDROCEPHALUS

Cognitive deterioration and gait balance disturbances are the core symptoms of idiopathic normal pressure patients with normal pressure hydrocephalus – NHP (J. Larson et al, 2021). The manifestations caused by NPH directly foul the patient’s autonomy. Rehabilitation in NPH and supervised physical exercise are important factors to improve patient’s functions (J. Rydja et al, 2021). Music therapy and background music have cognitive, psychosocial, behavioural, and motor benefits for people with neurological disorders. Various forms and genres of music can be engaging, emotional, physical, personal, social, persuasive, and music also promotes synchronization of movement (O. Brancatisano et al., 2020). The process of music therapy intervention was structured and designed according to American Music Therapy Association (2005) in a 3-step process of preparation, implementation, and evaluation. Background music and instrumental and movement music activities were aimed at relaxation and cognitive stimulation in a patient with NPH during physiotherapy. In instrumental activities three music instruments were used, two Orff instruments a tambourine, a rattle, and a plastic string resembling an accordion (made from recycled material) – to improve the range of movements, strength, endurance, and coordination of the upper limb bilaterally and to improve walking motor skills. Furthermore, we selected background music according to the patient’s taste and choice. The music genres in our sessions were electronic music, pop, and relaxing jazz: The music styles were Synth-pop, Ambient, Disco, Eurodance, Dance-pop and Relaxing jazz. A total of 5 music therapy sessions were held within two months. Each session lasted for 60 min. We observed the following changes in the patient: The mechanism of regulation of fine motor movements was affected in his upper arm bilaterally, and communication skills were also improved. The gross motor skills in upper arm improved bilaterally. The walking speed was more pronounced, and his submaximal performance distance was extended. During background music the patient myofascially relaxed – the spasticity began to subside, and music induced psychological and physical well-being on his emotional level.

The repeated bout effect of traditional resistance training on cycling efficiency and performance

PurposeThis study examined the repeated bout effect of two resistance training bouts on cycling efficiency and performance.MethodsTen male resistance-untrained cyclists (age 38 ± 13 years; height 180.4 ± 7.0 cm; weight 80.1 ± 10.1; kg; VO2max 51.0 ± 7.6 ml.kg−1.min−1) undertook two resistance training bouts at six-repetition maximum. Blood creatine kinase (CK), delayed-onset of muscle soreness (DOMS), counter-movement jump (CMJ), squat jump (SJ), submaximal cycling and time-trial performance were examined prior to (Tbase), 24 (T24) and 48 (T48) h post each resistance training bout.ResultsThere were significantly lower values for DOMS (p = 0.027) after Bout 2 than Bout 1. No differences were found between bouts for CK, CMJ, SJ and submaximal cycling performance. However, jump height (CMJ and SJ) submaximal cycling measures (ventilation and perceived exertion) were impaired at T24 and T48 compared to Tbase (p < 0.05). Net efficiency during submaximal cycling improved at Bout 2 (23.8 ± 1.2) than Bout 1 (24.3 ± 1.0%). There were no changes in cycling time-trial performance, although segmental differences in cadence were observed between bouts and time (i.e. Tbase vs T24 vs T48; p < 0.05).ConclusionCyclists improved their cycling efficiency from Bout 1 to Bout 2 possibly due to the repeated bout effect. However, cyclists maintained their cycling completion times during exercise-induced muscle damage (EIMD) in both resistance training bouts, possibly by altering their cycling strategies. Thus, cyclists should consider EIMD symptomatology after resistance training bouts, particularly for cycling-specific technical sessions, regardless of the repeated bout effect.

Unsupervised Exercise Intervention vs. Adherence to a Mediterranean Diet Alone: The Role of Bioelectrical Impedance Vector Analysis and Cardiovascular Performance in Liver-Transplanted Recipients.

(1) Background: Cardiovascular disease is one of the leading causes of mortality after liver transplantation. Body composition and cardiovascular performance assessment represent a potential approach for modulating lifestyle correction and proper follow-up in chronic disease patients. This study aimed to verify the additional role of an unsupervised physical activity program in a sample of male liver transplant recipients who follow the Mediterranean diet. (2) Methods: Thirty-three male liver transplant recipients were enrolled. Sixteen subjects followed a moderate-intensity home exercise program in addition to nutritional support, and seventeen received advice on the Mediterranean diet. After six months, bioelectrical vector impedance analysis (BIVA) and cardiopulmonary exercise testing (CPET) were performed. (3) Results: No differences in CPET (VO2 peak: exercise 21.4 ± 4.1 vs. diet 23.5 ± 6.5 mL/kg/min; p = 0.283) and BIVA (Z/H: exercise 288.3 ± 33.9 vs. diet 310.5 ± 34.2 Ω/m; p = 0.071) were found. Furthermore, the BIVA values of resistance correlate with the submaximal performance of the Ve/VCO2 slope (R = 0.509; p < 0.05) and phase angle with the maximal effort of the VO2 peak (R = 0.557; p < 0.05). (4) Conclusions: Unsupervised physical exercise alone for six months does not substantially modify liver transplant recipients' cardiovascular performance and hydration status, despite their adherence to a Mediterranean diet. The body composition analysis is useful to stratify the risk profile, and it is potentially associated with better outcomes in transplanted subjects.

Comparable Ventilatory Inefficiency at Maximal and Submaximal Performance in COPD vs. CHF subjects: An Innovative Approach.

Currently, excess ventilation has been grounded under the relationship between minute-ventilation/carbon dioxide output ( V ˙ E - V ˙ CO 2 ). Alternatively, a new approach for ventilatory efficiency ( η E V ˙ ) has been published. Our main hypothesis is that comparatively low levels of η E V ˙ between chronic heart failure (CHF) and chronic obstructive pulmonary disease (COPD) are attainable for a similar level of maximum and submaximal aerobic performance, conversely to long-established methods ( V ˙ E - V ˙ CO 2 slope and intercept). Both groups performed lung function tests, echocardiography, and cardiopulmonary exercise testing. The significance level adopted in the statistical analysis was 5%. Thus, nineteen COPD and nineteen CHF-eligible subjects completed the study. With the aim of contrasting full values of V ˙ E - V ˙ CO 2 and η V ˙ E for the exercise period (100%), correlations were made with smaller fractions, such as 90% and 75% of the maximum values. The two groups attained matched characteristics for age (62±6 vs. 59±9 yrs, p>.05), sex (10/9 vs. 14/5, p>0.05), BMI (26±4 vs. 27±3 Kg m2, p>0.05), and peak V ˙ O 2 (72±19 vs. 74±20 %pred, p>0.05), respectively. The V ˙ E - V ˙ CO 2 slope and intercept were significantly different for COPD and CHF (27.2±1.4 vs. 33.1±5.7 and 5.3±1.9 vs. 1.7±3.6, p<0.05 for both), but η V ˙ E average values were similar between-groups (10.2±3.4 vs. 10.9±2.3%, p=0.462). The correlations between 100% of the exercise period with 90% and 75% of it were stronger for η V ˙ E (r>0.850 for both). The η V ˙ E is a valuable method for comparison between cardiopulmonary diseases, with so far distinct physiopathological mechanisms, including ventilatory constraints in COPD.

The effects of endurance training on muscle oxygen desaturation during incremental exercise tests: a systematic review and meta-analysis.

Minimum muscle oxygen saturation (SmO2min) measured via near-infrared spectroscopy (NIRS) is a common measure during incremental exercise testing (IET). Our objective was to determine the effects of pre-to-post endurance training on SmO2min (ΔSmO2min) during an IET, using a meta-analysis. MEDLINE, EMBASE, and SPORTDiscus. Studies including healthy individuals had to meet the following criteria: (1) endurance training intervention; (2) peripheral muscle NIRS; (3) incremental exercise test pre/post training; (4) SmO2 or analogous saturation parameter measured. A PEDro scale was used for risk of bias analysis. A random effect meta-analysis model was used to synthesize the effect of training on ΔSmO2min in individual studies. Statistical heterogeneity was quantified using I2 statistic. A meta-regression was used to estimate the effect of training on the relationship between peak cycling power output (Wpeak), peak pulmonary oxygen uptake (V˙O2peak), and ΔSmO2min. A mixed-effect model was used to estimate categorical variables. Five studies met the inclusion criteria. No difference in SmO2min was detected following training pre- and post-intervention IETs. A trend for an effect of training on the relationship between Wpeak and ΔSmO2min was observed (p = 0.06). This meta-analysis showed no effects of endurance training on SmO2min during an IET. Our results showed a trend for an effect of training on the relationship between Wpeak and ΔSmO2min, with no effect for V˙O2peak and ΔSmO2min. It is possible that SmO2min is not affected by endurance training, and may be used as a physiological marker for improvements in submaximal performance rather than at peak.

Ineficiência Ventilatória Comparável no Desempenho Máximo e Submáximo em Indivíduos com DPOC e ICC: Uma Abordagem Inovadora

Abstract Background: Currently, excess ventilation has been grounded under the relationship between minute-ventilation/carbon dioxide output ( V ˙ E − V ˙ CO 2). Alternatively, a new approach for ventilatory efficiency ( η E V ˙) has been published. Objective: Our main hypothesis is that comparatively low levels of η E V ˙ between chronic heart failure (CHF) and chronic obstructive pulmonary disease (COPD) are attainable for a similar level of maximum and submaximal aerobic performance, conversely to long-established methods ( V ˙ E − V ˙ CO 2 slope and intercept). Methods: Both groups performed lung function tests, echocardiography, and cardiopulmonary exercise testing. The significance level adopted in the statistical analysis was 5%. Thus, nineteen COPD and nineteen CHF-eligible subjects completed the study. With the aim of contrasting full values of V ˙ E − V ˙ CO 2 and η V ˙ E for the exercise period (100%), correlations were made with smaller fractions, such as 90% and 75% of the maximum values. Results: The two groups attained matched characteristics for age (62±6 vs. 59±9 yrs, p&gt;.05), sex (10/9 vs. 14/5, p&gt;0.05), BMI (26±4 vs. 27±3 Kg m2, p&gt;0.05), and peak V ˙ O 2 (72±19 vs. 74±20 %pred, p&gt;0.05), respectively. The V ˙ E − V ˙ CO 2 slope and intercept were significantly different for COPD and CHF (27.2±1.4 vs. 33.1±5.7 and 5.3±1.9 vs. 1.7±3.6, p&lt;0.05 for both), but η V ˙ E average values were similar between-groups (10.2±3.4 vs. 10.9±2.3%, p=0.462). The correlations between 100% of the exercise period with 90% and 75% of it were stronger for η V ˙ E (r&gt;0.850 for both). Conclusion: The η V ˙ E is a valuable method for comparison between cardiopulmonary diseases, with so far distinct physiopathological mechanisms, including ventilatory constraints in COPD.

Predictive utility of health-related quality of life and the 6-minute walking test in transthyretin amyloid cardiomyopathy - a comparison

Abstract Introduction Both health-related quality of life (HR-QoL) as well as submaximal physical performance as assessed using the 6-minute walking test (6-MWT) have been shown to predict outcome in heart failure. However, it is currently unclear how the predictive utility of different HR-QoL measurement tools compares to the 6-MWT in transthyretin amyloid cardiomyopathy (ATTR-CM). Aims To evaluate predictive utility of the Kansas City Cardiomyopathy Questionnaire (KCCQ), the Minnesota Living with Heart Failure Questionnaire (MLHFQ) and the EuroQol Five Dimensions Questionnaire (EQ-5D) in comparison to the 6-MWT in patients with ATTR-CM. Methods and results 186 patients diagnosed with ATTR-CM were included and data from 474 visits (2.55 per patient) was analysed. All scores and distance walked in the 6-MWT were transformed into Z-values by subtracting the mean and dividing by the standard deviation. In a cox regression analysis for all-cause mortality adjusted for age and sex, the KCCQ [Hazard Ratio (HR): 0.560, p = &amp;lt; 0.001], the EQ-5D visual analogue scale (HR: 0.712, p = 0.005) and the MLHFQ (HR: 0.613, p = &amp;lt; 0.001) proved predictive of outcome. For heart failure hospitalisation, the KCCQ (HR: 0.455, p = &amp;lt; 0.001), the EQ-5D overall score (HR: 0.753, p = 0.007), the EQ-5D visual analogue scale (HR: 0.631, p = &amp;lt; 0.001) and the MLHFQ score (HR: 0.466, p = &amp;lt; 0.001) were shown to be of high predictive utility. In comparison, the 6-MWT HRs were 0.434 and 0.544 for mortality and heart failure hospitalisation, respectively (p = &amp;lt; 0.001). Conclusion Prognostic utility of the KCCQ and MLHFQ scores is non-inferior to the 6-MWT in ATTR-CM. While much more simplistic, the EQ-5D is lacking behind the other tested questionnaires with regard to predictive utility.

Post-COVID-19 syndrome: Physical capacity, fatigue and quality of life.

Post-Covid-19 syndrome is defined as the persistence of symptoms beyond 3 months after severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. The most common symptoms include reduced exercise tolerance and capacity, fatigue, neurocognitive problems, muscle pain and dyspnea. The aim of our work was to investigate exercise capacity and markers of subjective wellbeing and their independent relation to post-COVID-19 syndrome. We examined a total of 69 patients with post-COVID-19 syndrome (23 male/46 female; age 46±12 years; BMI 28.9±6.6 kg/m2) with fatigue and a score ≥22 in the Fatigue Assessment Scale (FAS). We assessed exercise capacity on a cycle ergometer, a 6-minute walk test, the extent of fatigue (FAS), markers of health-related quality of life (SF-36 questionnaire) and mental health (HADS). On average the Fatigue Assessment Scale was 35.0±7.4 points. Compared with normative values the VO2max/kg was reduced by 8.6±5.8 ml/min/kg (27.7%), the 6MWT by 71±96 m (11.9%), the health-related quality of life physical component score by 15.0±9.0 points (29.9%) and the mental component score by 10.6±12.8 points (20.6%). Subdivided into mild fatigue (FAS score 22-34) and severe fatigue (FAS score ≥35), patients with severe fatigue showed a significant reduction of the 6-minute walk test by 64±165 m (p<0.01) and the health-related quality of life physical component score by 5.8±17.2 points (p = 0.01). In multiple regression analysis age (β = -0.24, p = 0.02), sex (β = 0.22, p = 0.03), mental (β = -0.51, p<0.01) and physical (β = -0.44, p<0.01) health-related quality of life and by trend the 6-minute walk test (β = -0.22, p = 0.07) were associated with the FAS. Patients with post-COVID-19 syndrome show reduced maximal and submaximal physical performance as well as limitations in quality of life, particularly pronounced in the physical components. These results are essentially influenced by the severity of fatigue and implicating the need for targeted treatments.

Physiological Characteristics of Competitive Male Junior Cyclists Transitioning to the Under-23 Level: A Retrospective Comparative Study.

The purpose of the current investigation was to retrospectively assess possible differences in physiological performance characteristics between junior cyclists signing a contract with an under-23 (U23) development team versus those failing to sign such a contract. Twenty-five male junior cyclists (age: 18.1 [0.7]y, stature: 181.9 [6.0]cm, body mass: 69.1 [7.9]kg, peak oxygen uptake: 71.3 [6.2]mL·min-1·kg-1) were assigned to this investigation. Between September and October of the last year in the junior category, each cyclist performed a ramp incremental exercise test to determine certain physiological performance characteristics. Subsequently, participants were divided in 2 groups: (1)those signing a contract with a U23 development team (JUNIORU23) and (2)those failing to sign such a contract (JUNIORNON-U23). Unpaired t tests were used to assess possible between-groups differences in physiological performance characteristics. The level of statistical significance was set at P < .05 two tailed. No significant between-groups differences in submaximal (ie,gas exchange threshold, respiratory compensation point) and maximal physiological performance characteristics (ie,peak work rate, peak oxygen uptake) expressed in absolute values (ie,L·min-1, W) were observed (P > .05). However, significant between-groups differences were observed when physiological performance characteristics were expressed relative to the cyclists' body weights (P < .05). The current investigation showed that junior cyclists stepping up to a U23 development team might be retrospectively differentiated from junior cyclists not stepping up based on certain physiological performance characteristics, which might inform practitioners and/or federations working with young cyclists during the long-term athletic development process.

The relation between left atrial and left ventricular size in a healthy population

Abstract Funding Acknowledgements Type of funding sources: Public Institution(s). Main funding source(s): The project was funded by grants from The Liaison Committee for Education, Research and Innovation in Central Norway, St. Olavs University Hospital (Trondheim, Norway), Nord-Trøndelag Hospital Trust (Levanger, Norway), and Simon Fougner Hartmann's Family Fund (Copenhagen, Denmark). Background The left atrium (LA) and ventricle (LV) are closely linked and adapt to meet metabolic demands. Reduced LV end-diastolic volume (LVEDV) and increased LA end-systolic volume (LAESV) is common in patients with diastolic dysfunction and with higher age. The remodeling of LA and LV in response to endurance exercise is thought to be balanced, and thus, the LA:LV ratio could help discriminate pathologic from physiologic LA enlargement. Purpose We aimed to describe the relative LA and LV chamber remodeling associated with the clinical characteristics age, sex, maximal oxygen consumption (VO2peak), HbA1C, body mass index, systolic blood pressure, and diastolic dysfunction. Methods Healthy participants included in a large longitudinal population study underwent clinical evaluation and cardiopulmonary exercise testing (CPET) in 2006–2008, followed by comprehensive echocardiography and CPET in 2017–18. Exclusion criteria were: 1) submaximal performance during CPET, 2) atrial fibrillation, or 3) presence of heart failure or a history of myocardial infarction. All examinations were performed by highly experienced personnel. All echocardiographic exams and analyses were performed by personnel affiliated a European Association of Cardiovascular Imaging accredited echo-laboratory. Results In total, 1,349 participants were included. Mean (SD) age was 58 (12) years, and 52% were women. The LA:LV ratio was higher with higher age due to lower LVEDV and stable LAESV (Figure 1). Age alone explained 12% (p&amp;lt;0.001) of variance for the LA:LV ratio and men had higher LA:LV ratios than women (0.55 vs. 0.50, p &amp;lt;0.001). All examined clinical characteristics showed significant associations with LA:LV ratios in univariate regression analyses. In adjusted analyses, increased VO2peak was significantly associated with increased LA:LV ratio, but with a small effect-size without clinical significance. In the subsample with indexed LAESV &amp;gt;34mL/m2, increased VO2peak was significantly associated with increased LA:LV-ratio in adjusted analyses (p &amp;lt;0.001). Ten-year change in VO2peak was not significantly associated with LA:LV ratio in adjusted models for the total population, nor in the subgroup with indexed LAESV &amp;gt;34 mL (p = 0.181). Multiple logistic regression showed that higher LA:LV ratio was associated with increased risk of diastolic dysfunction with an OR (95% CI) of 2.4 (1.5, 4.0) per SD increase in LA:LV-ratio, adjusted for age, sex, systolic blood pressure, HbA1c, and BMI (p &amp;lt; 0.001). LA strain measures, E/e’ ratio, and TR velocity were significantly associated with the LA:LV ratio, while other diastolic function parameters were not. Conclusion The LA:LV ratio increases with higher age due to reduced LVEDV and stable LAESV. VO2peak was not a robust predictor of LA:LV ratio in this population. Future studies should evaluate the relative remodeling of LA and LV with repeated measurements of echocardiographic indices and CPET to better define the role of this ratio.

Glucocorticoids and physical performance: A systematic review with meta-analysis of randomized controlled trials.

This systematic review with meta-analysis investigates the effect of glucocorticoids on maximal and submaximal performance in healthy subjects. We searched for randomised controlled trials investigating the effect of glucocorticoids on physical performance in Web of Science, Scopus, Medline, Embase and SportDiscus in March 2021. Risk of bias was assessed with the revised Cochrane Collaboration Risk of Bias Tool (RoB2). Data from random effect models are presented as standardized difference in mean (SDM) with 95% confidence interval. We included 15 studies comprising 175 subjects. Two studies had high risk of bias. Glucocorticoids had a small positive effect on maximal physical performance compared to placebo (SDM 0.300, 95% CI 0.080 to 0.520) and the SDM for the 13 included comparisons was not heterogeneous (I2 = 35%, p = 0.099). Meta regression found no difference in the effect of acute treatment vs. prolonged treatment or oral ingestion vs. inhalation (p > 0.124). In stratified analysis prolonged treatment (SDM 0.428, 95% CI 0.148 to 0.709) and oral ingestion (SDM 0.361, 95% CI 0.124 to 0.598) improved physical performance. Glucocorticoids improved aerobic performance (SDM 0.371, 95% CI 0.173 to 0.569) but not anaerobic performance (p = 0.135). Glucocorticoids did not change energy expenditure during submaximal performance (SDM 0.0.225 95% CI -0.771 to 0.112). This study indicates that glucocorticoids improves maximal performance and aerobic performance. Glucocorticoids did not affect the energy expenditure during submaximal performance. The conclusions are based on relatively few subjects leading to limited statistical power and uncertain estimates. Still, these results are consistent and should be of interest to WADA and anyone concerned about fair play. Open Science Framework 2021-04-29 (https://osf.io/fc29t/).

Metabolic correlates to critical speed in murine models of sickle cell disease.

Introduction: Exercise intolerance is a common clinical manifestation in patients with sickle cell disease (SCD), though the mechanisms are incompletely understood. Methods: Here we leverage a murine mouse model of sickle cell disease, the Berkeley mouse, to characterize response to exercise via determination of critical speed (CS), a functional measurement of mouse running speed upon exerting to exhaustion. Results: Upon observing a wide distribution in critical speed phenotypes, we systematically determined metabolic aberrations in plasma and organs-including heart, kidney, liver, lung, and spleen-from mice ranked based on critical speed performances (top vs. bottom 25%). Results indicated clear signatures of systemic and organ-specific alterations in carboxylic acids, sphingosine 1-phosphate and acylcarnitine metabolism. Metabolites in these pathways showed significant correlations with critical speed across all matrices. Findings from murine models were thus further validated in 433 sickle cell disease patients (SS genotype). Metabolomics analyses of plasma from 281 subjects in this cohort (with HbA < 10% to decrease confounding effects of recent transfusion events) were used to identify metabolic correlates to sub-maximal exercise test performances, as measure by 6min walking test in this clinical cohort. Results confirmed strong correlation between test performances and dysregulated levels of circulating carboxylic acids (especially succinate) and sphingosine 1-phosphate. Discussion: We identified novel circulating metabolic markers of exercise intolerance in mouse models of sickle cell disease and sickle cell patients.

Fenugreek and Its Effects on Muscle Performance: A Systematic Review.

Fenugreek extracts possess promising physiological and pharmacological properties in human and animal models. This review aims to provide a scientific and comprehensive analysis of the literature on the effects of fenugreek extracts on muscle performance. An extensive online search was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement guidelines. The main medical and scientific engines were searched for articles from May 1981 to May 2021 to capture all scientific studies focused on the effect of fenugreek on muscle and exercise or sport. Out of 81 studies acquired, six eligible randomized controlled trials (RCTs) were included in the qualitative analysis. Four RCTs observed that fenugreek supplementation had significantly improved muscle strength, repetitions to failure (muscle endurance), submaximal performance index, lean body mass, and reduced body fat. Among the remaining two trials, one reported the significant effect of fenugreek extracts on the rate of muscle glycogen resynthesis during post-exercise recovery; however, the other failed to do so. Those two trials were weak, with a minimal sample size (<10). Further, fenugreek glycoside supplementation with sapogenins and saponins reported substantial anabolic and androgenic activity, influencing testosterone levels and muscle performance. It was useful during eight weeks of resistance training without any clinical side effects. Fenugreek with creatine supplementation improved creatine uptake without the necessity of high carbohydrate intake. Hence, fenugreek extracts can be a helpful natural supplement and ergogenic aid for athletes. However, it is better to be aware of doping and liver and kidney damage before using the fenugreek supplement.

Effect of Walking Course Length on 6MWT: An Experimental Study

Introduction: The 6-minute walk test (6MWT) is a validated tool of submaximal intensity used as an objective measure of functional exercise capacity. Changes in 6-minute walk distance (6MWD) are used to evaluate the efficacy of therapeutic interventions. American Thoracic Society (ATS) guidelines state that the walking course for the 6MWT must be 30 m. In a primary care physiotherapy setting, a 30 m straight course is often not available. Space limitations often force clinicians and researchers to conduct 6MWT on shorter courses. The purpose of this study was to determine the influence of 5, 10, 15, and 30 m course lengths on 6MWD and physiological parameters during the 6MWT. Materials and methods: A total of 80 healthy adults from 18 to 30 years performed four 6MWTs along 5, 10, 15, and 30 m course lengths in a corridor randomly, on consecutive days. The 6MWD and vital parameters on all four course lengths were recorded. Walking speed and maximal oxygen uptake (VO2 max) were calculated. Results: There was a significant difference in 6MWD, walking speed, and VO2 max over 5, 10, 15, and 30 m course lengths during 6MWT (p &lt; 0.05). There was no significant difference observed in the change in heart rate (HR) between 6MWT on 5 and 10 m course lengths and 6MWT on 15 and 30 m course lengths (p &gt; 0.05). Conclusion: The course length strongly influences the performance during the 6MWT and the results on 5, 10, 15, and 30 m courses are not interchangeable with each other. However, there was a similar submaximal cardiac performance on 15 and 30 m course lengths.