Physiological measures in participants with chronic fatigue syndrome, multiple sclerosis and healthy controls following repeated exercise: a pilot study

• Published in: Clinical physiology and functional imaging Vol. 38; no. 4; pp. 639 - 644
• Main Authors: Hodges, L. D., Nielsen, T., Baken, D.
• Format: Journal Article
• Language: English
• Published: England Wiley Subscription Services, Inc 01.07.2018
• Subjects: Blood pressure; Carbon dioxide; cardiovascular exercise testing; Chronic fatigue syndrome; Data analysis; Data processing; Fatigue; Fatigue tests; Heart rate; Multiple sclerosis; Oxygen consumption; Physical training; Physiological responses; Physiology; postexertional malaise; Pressurized water reactors; Working conditions; Workload; Workloads; postexertional malaise; fatigue; cardiovascular exercise testing
• ISSN: 1475-0961; 1475-097X
• DOI: 10.1111/cpf.12460

Summary Purpose To compare physiological responses of chronic fatigue syndrome (CFS/ME), multiple sclerosis (MS) and healthy controls (HC) following a 24‐h repeated exercise test. Methods Ten CFS, seven MS and 17 age‐ and gender‐matched healthy controls (10, CFS HC; and seven, MS HC) were recruited. Each participant completed a maximal incremental cycle exercise test on day 1 and again 24 h later. Heart rate (HR), blood pressure (BP), rating of perceived exertion (RPE), oxygen consumption (V˙O2), carbon dioxide production and workload (WL) were recorded. Data analysis investigated these responses at anaerobic threshold (AT) and peak work rate (PWR). Results On day 2, both CFS and MS had significantly reduced max workload compared to HC. On day 2, significant differences were apparent in WL between CFS and CFS HC (93 ± 37 W, 132 ± 42 W, P<0·042). CFS workload decreased on day 2, alongside a decrease in HR but with an increase in V˙O2 (ml kg min−1). This was in comparison with an increase in WL, HR and V˙O2 for CFS HC. MS demonstrated a decreased WL compared to MS HC on both days of the study (D1 81 ± 30 W, 116 ±30 W; D2 84 ± 29 W, 118 ± 36 W); however, patients with MS were able to achieve a higher WL on day 2 alongside MS HC. Conclusion These results suggest that exercise exhibits a different physiological response in MS and CFS/ME, demonstrating repeated cardiovascular exercise testing as a valid measure for differentiating between fatigue conditions.