Discover the most talked about and latest scientific content & concepts.

Concept: Exercise intolerance


During competition, high-performance swimmers are subject to repeated physical demands that affect their final performance. Measurement of lactate concentration in blood seeks to indirectly gauge physiologic responses to the increase in physical exercise. Swimmers face multiple maximal-exertion events during competition. Strenuous physical exercise leads to fatigue and, thus, a decrease in sports performance.

Concepts: Psychology, Physical exercise, Test method, Exercise physiology, Swimming, Exercise intolerance, Knitting, Passive voice


Pre-exercise nutritional practices for active females exercising for mood, cognitive and appetite benefits are not well established. Results from an initial field pilot study showed that higher energy intake at breakfast was associated with lower fatigue and higher overall mood and alertness post-exercise (all p < 0.05). In a follow-up, randomised, controlled trial, 24 active women completed three trials in a balanced, cross-over design. At 0815 h participants completed baseline cognitive tasks, mood and appetite visual analogue scales (VAS) and were administered a cereal breakfast (providing 118 or 236 kcal) or no breakfast. After 45 min, they completed a 30 min run at 65% heart rate reserve (HRR). Parameters were re-assessed immediately after exercise, then hourly until lunch (~1240 h), immediately post-lunch and at 1500 and 1900 h via a mobile phone. Breakfast enhanced feelings of relaxation before lunch (p < 0.05, d > 0.40), though breakfast was detrimental for working memory mid-afternoon (p = 0.019, d = 0.37) and mental fatigue and tension later in the day (all p < 0.05, d > 0.038). Breakfast was also beneficial for appetite control before lunch irrespective of size (all p < 0.05, d > 0.43). These data provide information on pre-exercise nutritional practices for active females and suggest that a small breakfast eaten prior to exercise can benefit post-exercise mood and subjective appetite ratings.

Concepts: Clinical trial, Obesity, Eating, Pulse, Weight loss, Heart rate, Mobile phone, Exercise intolerance


Work-related physical activity (PA), in terms of peak loads, sustained and/or repetitive contractions presents risk factors for the development of muscular pain and disorders. However, PA as training tailored to the employee’s work exposure, health, and physical capacity offers prevention and rehabilitation. We suggest the concept of “Intelligent Physical Exercise Training” relying on evidence-based sports science training principles.This is an open-access article distributed under the terms of the Creative Commons Attribution-Non Commercial-No Derivatives License 4.0 (CCBY-NC-ND), where it is permissible to download and share the work provided it is properly cited. The work cannot be changed in any way or used commercially without permission from the journal.

Concepts: Obesity, Muscle, Physical exercise, Exercise, Exercise physiology, Physical fitness, Exercise intolerance, Creative Commons


Physical exercise mitigates fatigue during androgen deprivation therapy (ADT); however, the effects of different exercise prescriptions are unknown.

Concepts: Cancer, Metastasis, Obesity, Randomized controlled trial, Prostate cancer, Testosterone, Androgen, Exercise intolerance


Background: Studies have shown the effectiveness of a few weekly pilates sessions as helping to reduce lower back pain (LBP). However many patients fear that physical activity can actually make the pain and disability worse. Design: We carried out this observational prospective clinical study to look at the effects that taking part in daily pilates has one on side and on the other the effects of LBP management without physical exercise. Setting: The volunteers who participated in this study were recruited from among some local cultural associations. Population: Patients affected by LBP were evaluated. Methods: The subjects were 60 volunteers (27 males and 33 females) with a mean age of 51.2 years who had chronic low back pain (CLBP). They were allocated to pilates group (N.=30) or inactivity control group (N.=30). The pilates group performed one-hour lesson of pilates exercise, 5 lessons per week during the following 6 months. The inactivity group continued with their normal daily activities. The Roland-Morris Disability, the Oswestry, the SF-36 and the Spinal Functional Sort Questionaries of all subjects were measured at the baseline (T1) and at 6 months (T2). Results: At T2 improvements were observed in the pilates group with increases in physical and social functioning, general health and vitality (P<0.05) and decreases in disability and pain (P<0.05). The inactivity group showed worsening in the same measures at T2. Conclusion: We found an important improvement of pain, disability and physical and psychological perception of health in individuals who did the daily sessions of pilates. Clinical Rehabilitation Impact: Some authors underlined the possible risk of a lack of adherence to an exercise program at home. This study suggests that a daily pilates program is effective for the management of CLBP. On the other hand, the inactivity contributes to further worsening, inducing a vicious cycle in which pain and physical activity intolerance follow each other.

Concepts: Scientific method, Spinal disc herniation, Low back pain, Back pain, Effectiveness, Acupuncture, Massage, Exercise intolerance


This review aims to evaluate the current body of literature investigating the effect of whole body cryotherapy on recovery after exercise. A systematic search was conducted to investigate the effect of whole body cryotherapy (WBC, exposure to temperatures between -110 to -190°C) on markers of recovery after damaging exercise in healthy, physically active subjects. Of the 16 eligible articles extracted, ten induced muscle damage using controlled exercise in a laboratory setting, while six induced damage during sport-specific training. Results indicated that muscle pain was reduced in 80% of studies following WBC. Two applied studies found recovery of athletic capacity and performance with WBC improved, variables of this nature were also improved in 71% of studies using controlled exercise. Further benefits of WBC treatment included reduction of systemic inflammation and lower concentrations of markers for muscle cell damage. These results suggest that WBC may improve recovery from muscle damage, with multiple exposures more consistently exhibiting improvements in recovery from pain, loss of muscle function, and markers of inflammation and damage. The diversity in muscle damage protocols, exposure timing with regards to exercise, as well as temperatures, duration and frequencies of exposure, make specific recommendations preliminary at present.

Concepts: Inflammation, Better, Improve, Obesity, Muscle, Physical exercise, Exercise physiology, Exercise intolerance


Objectives The present study evaluated the efficacy of an exercise intervention to reduce work-related fatigue (emotional exhaustion, overall fatigue, and need for recovery). The effects of exercise on self-efficacy, sleep, work ability, cognitive functioning and aerobic fitness (secondary outcomes) were also investigated. Methods Employees with high levels of work-related fatigue were randomly assigned to either a 6-week exercise intervention (EI; N=49) or a wait-list control group (WLC; N=47). All participants were measured pre- (T0) and post-intervention (T1). EI participants were also measured 6 (T2) and 12 weeks (T3) after the end of the intervention. Analyses were based on intention-to-treat (ITT) and per-protocol (PP). PP analyses only included EI participants (N=31) who completed the intervention and WLC participants (N= 35) who did not increase their exercise level during the wait period. Results Analyses of covariance (ANCOVA) revealed that, at T1, the EI group reported lower emotional exhaustion and overall fatigue than the WLC group, however, only according to PP analyses. Both according to ITT and PP analyses, EI participants showed higher sleep quality, work ability, and self-reported cognitive functioning at T1 compared to WLC participants. Intervention effects were maintained at T2 and T3. Conclusions The exercise intervention had enduring effects on work-related fatigue and broader indicators of employee well-being. This study demonstrates that, in case of work-related fatigue, exercise does constitute a powerful medicine for those who comply with the treatment.

Concepts: Randomized controlled trial, Effectiveness, Exercise, Sleep deprivation, Efficacy, Somnolence, Exercise physiology, Exercise intolerance


Music is known to be capable of reducing perceived exertion during strenuous physical activity. The current interpretation of this modulating effect of music is that music may be perceived as a diversion from unpleasant proprioceptive sensations that go along with exhaustion. Here we investigated the effects of music on perceived exertion during a physically strenuous task, varying musical agency, a task that relies on the experience of body proprioception, rather than simply diverting from it. For this we measured psychologically indicated exertion during physical workout with and without musical agency while simultaneously acquiring metabolic values with spirometry. Results showed that musical agency significantly decreased perceived exertion during workout, indicating that musical agency may actually facilitate physically strenuous activities. This indicates that the positive effect of music on perceived exertion cannot always be explained by an effect of diversion from proprioceptive feedback. Furthermore, this finding suggests that the down-modulating effect of musical agency on perceived exertion may be a previously unacknowledged driving force for the development of music in humans: making music makes strenuous physical activities less exhausting.

Concepts: Sense, Mind, Activity, Task, Exercise physiology, Proprioception, Music, Exercise intolerance


ObjectivesReduced functional capacity and post-exertional fatigue following physical activity are hallmark symptoms of chronic fatigue syndrome (CFS) and may even qualify for biomarker status. That these symptoms are often delayed may explain the equivocal results for clinical cardiopulmonary exercise testing among individuals with CFS. Test reproducibility in healthy subjects is well documented. This may not be the case with CFS due to delayed recovery symptoms. The objectives for this study was to determine the discriminative validity of objective measurements obtained during CPET to distinguish individuals with CFS from non-disabled sedentary individuals.MethodsGas exchange data, workloads and related physiological parameters were compared between 51 individuals with CFS and 10 control subjects, all females, for two maximal exercise tests separated by 24 hours.ResultsMultivariate analysis showed no significant differences between controls and CFS for Test 1. However, for Test 2 the individuals with CFS achieved significantly lower values for oxygen consumption and workload at peak exercise and at the ventilatory/anaerobic threshold. Follow-up classification analysis differentiated between groups with an overall accuracy of 95.1%.ConclusionsThe lack of any significant differences between groups for the first exercise test would appear to support a deconditioning hypothesis for CFS symptoms. However, results from the second test indicate the presence of a CFS related post-exertional fatigue. It might be concluded that a single exercise test is insufficient to reliably demonstrate functional impairment in individuals with CFS. A second test may be necessary to document the atypical recovery response and protracted fatigue possibly unique to CFS, which can severely limit productivity in the home and workplace.

Concepts: Scientific method, Obesity, Physical exercise, Overweight, Psychometrics, Fatigue, Chronic fatigue syndrome, Exercise intolerance


BACKGROUND: Biomarkers of peripheral muscle fatigue (BPMFs) are used to offer insights into mechanisms of exhaustion during exercise in order to detect abnormal fatigue or to detect defective metabolic pathways. This review aims at describing recent advances and future perspectives concerning the most important biomarkers of muscle fatigue during exercise. RESULTS: BPMFs are classified according to the mechanism of fatigue related to adenosine-triphosphate-metabolism, acidosis, or oxidative-metabolism. Muscle fatigue is also related to an immunological response. impaired calcium handling, disturbances in bioenergetic pathways, and genetic responses. The immunological and genetic response may make the muscle susceptible to fatigue but may not directly cause muscle fatigue. Production of BPMFs is predominantly dependent on the type of exercise. BPMFs need to change as a function of the process being monitored, be stable without appreciable diurnal variations, correlate well with exercise intensity, and be present in detectable amounts in easily accessible biological fluids. The most well-known BPMFs are serum lactate and interleukin-6. The most widely applied clinical application is screening for defective oxidative metabolism in mitochondrial disorders by means of the lactate stress test. The clinical relevance of most other BPMFs, however, is under debate, since they often depend on age, gender, physical fitness, the energy supply during exercise, the type of exercise needed to produce the BPMF, and whether healthy or diseased subjects are investigated. CONCLUSIONS: Though the role of BPMFs during fatigue is poorly understood, measuring BPMFs under specific, standardised conditions appears to be helpful for assessing biological states or processes during exercise and fatigue.

Concepts: Medicine, Cancer, Metabolism, Adenosine triphosphate, Organism, Mitochondrion, Oxidative phosphorylation, Exercise intolerance