Carolina X. Sandler

Fatigue Exacerbation by Interval or Continuous Exercise in Chronic Fatigue Syndrome.

PURPOSE The objective of this study is to determine whether the typical exacerbation of symptoms in patients with chronic fatigue syndrome (CFS) after a bout of exercise differs between high-intensity interval training (HIIT) or continuous (CONT) aerobic exercise of the same duration and mechanical work. METHODS Participants with specialist-diagnosed CFS performed two 20-min bouts of cycling in a randomized crossover study. The bouts were either moderate-intensity continuous (70% age-predicted HR maximum) or high-intensity interval exercise, separated by at least 2 wk. Self-report questionnaires capturing fatigue, the related symptoms, and actigraphy were collected across 2 d before and 4 d after the exercise. Comparisons between exercise bouts were made using paired sample t-tests. RESULTS Fourteen moderately affected participants who were unable to work, but not bed bound, completed the study (nine female, 32 ± 10 yr, 67 ± 11 kg). Mechanical work was matched successfully between the exercise bouts (HIIT, 83,037, vs CONT, 83,348 J, P = 0.84). Mean HR (HIIT, 76% ± 5%, vs CONT, 73% ± 6% age-predicted HR maximum, P < 0.05) and RPE (6-20) in the legs (HIIT, 15.4 ± 1.4, vs CONT, 13.2 ± 1.2, P < 0.001) were higher for the interval compared with continuous exercise. Mean fatigue scores (0-10) were similar before each exercise challenge (HIIT, 4.5 ± 1.8, vs CONT, 4.1 ± 1.7, P = 0.43). Participants reported an increase in fatigue scores after both challenges (mean difference: HIIT, 1.0 ± 1.3, P < 0.01; CONT, 1.5 ± 0.7, P < 0.001), but these exacerbations in fatigue were not statistically or clinically different (P = 0.20). CONCLUSIONS High-intensity interval exercise did not exacerbate fatigue any more than continuous exercise of comparable workload. This finding supports evaluation of HIIT in graded exercise therapy interventions for patients with CFS.

Outcomes and predictors of response from an optimised, multi‐disciplinary intervention for chronic fatigue states

Medically unexplained chronic fatigue states are prevalent and challenging to manage. Cognitive behavioural therapy (CBT) and graded exercise therapy (GET) are effective in clinical trials. The evaluation of delivery in a standard healthcare setting is rare. An integrated treatment programme with individualised allocation of resources to patients’ needs was developed and implemented through an academic outpatient clinic. It was hypothesised that the programme would result in similar responses to those observed in the clinical trials.

Autonomic nervous system function, activity patterns, and sleep after physical or cognitive challenge in people with chronic fatigue syndrome

OBJECTIVE To explore changes in autonomic functioning, sleep, and physical activity during a post-exertional symptom exacerbation induced by physical or cognitive challenge in participants with chronic fatigue syndrome (CFS). METHODS Thirty-five participants with CFS reported fatigue levels 24-h before, immediately before, immediately after, and 24-h after the completion of previously characterised physical (stationary cycling) or cognitive (simulated driving) challenges. Participants also provided ratings of their sleep quality and sleep duration for the night before, and after, the challenge. Continuous ambulatory electrocardiography (ECG) and physical activity was recorded from 24-h prior, until 24-h after, the challenge. Heart rate (HR) and HR variability (HRV, as high frequency power in normalized units) was derived from the ECG trace for periods of wake and sleep. RESULTS Both physical and cognitive challenges induced an immediate exacerbation of the fatigue state (p<0.001), which remained elevated 24-h post-challenge. After completing the challenges, participants spent a greater proportion of wakeful hours lying down (p=0.024), but did not experience significant changes in sleep quality or sleep duration. Although the normal changes in HR and HRV during the transition from wakefulness to sleep were evident, the magnitude of the increase in HRV was significantly lower after completing the challenge (p=0.016). CONCLUSION Preliminary evidence of reduced nocturnal parasympathetic activity, and increased periods of inactivity, were found during post-exertional fatigue in a well-defined group of participants with CFS. Larger studies employing challenge paradigms are warranted to further explore the underlying pathophysiological mechanisms of post-exertional fatigue in CFS.

Cognitive remediation training improves performance in patients with chronic fatigue syndrome

Neurocognitive disturbance with subjectively-impaired concentration and memory is a common, disabling symptom reported by patients with chronic fatigue syndrome (CFS). We recently reported preliminary evidence for benefits of cognitive remediation as part of an integrated cognitive-behavioral therapy (CBT)/ graded exercise therapy (GET) program. Here, we describe a contemporaneous, case-control trial evaluating the effectiveness of an online cognitive remediation training program (cognitive exercise therapy; CET) in addition to CBT/GET (n=36), compared to CBT/GET alone (n=36). The study was conducted in an academic, tertiary referral outpatient setting over 12 weeks (11 visits) with structured, home-based activities between visits. Participants self-reported standardized measures of symptom severity and functional status before and after the intervention. Those in the CET arm also completed standardized neurocognitive assessment before, and following, treatment. The addition of formal CET led to significantly greater improvements in self-reported neurocognitive symptoms compared to CBT/GET alone. Subjective improvement was predicted by CET group and lower baseline mood disturbance. In the CET group, significant improvements in objectively-measured executive function, processing speed, and working memory were observed. These subjective and objective performance improvements suggest that a computerized, home-based cognitive training program may be an effective intervention for patients with CFS, warranting randomized controlled trials.

Randomised controlled trial of online continuing education for health professionals to improve the management of chronic fatigue syndrome: a study protocol

Introduction Chronic fatigue syndrome (CFS) is a serious and debilitating illness that affects between 0.2%–2.6% of the world’s population. Although there is level 1 evidence of the benefit of cognitive behaviour therapy (CBT) and graded exercise therapy (GET) for some people with CFS, uptake of these interventions is low or at best untimely. This can be partly attributed to poor clinician awareness and knowledge of CFS and related CBT and GET interventions. This trial aims to evaluate the effect of participation in an online education programme, compared with a wait-list control group, on allied health professionals’ knowledge about evidence-based CFS interventions and their levels of confidence to engage in the dissemination of these interventions. Methods and analysis A randomised controlled trial consisting of 180 consenting allied health professionals will be conducted. Participants will be randomised into an intervention group (n=90) that will receive access to the online education programme, or a wait-list control group (n=90). The primary outcomes will be: 1) knowledge and clinical reasoning skills regarding CFS and its management, measured at baseline, postintervention and follow-up, and 2) self-reported confidence in knowledge and clinical reasoning skills related to CFS. Secondary outcomes include retention of knowledge and satisfaction with the online education programme. The influence of the education programme on clinical practice behaviour, and self-reported success in the management of people with CFS, will also be assessed in a cohort study design with participants from the intervention and control groups combined. Ethics and dissemination The study protocol has been approved by the Human Research Ethics Committee at The University of New South Wales (approval number HC16419). Results will be disseminated via peer-reviewed journal articles and presentations at scientific conferences and meetings. Trial registration ACTRN12616000296437.