Muscle Haemodynamics and Oxygen Saturation during Exercise and Recovery in Chronic Fatigue Syndrome Patients, 2018, Singh et al.

Muscle Haemodynamics and Oxygen Saturation during Exercise and Recovery in Chronic Fatigue Syndrome Patients
Jyotpal Singh, Andy D. Roberts, Michael F. Harrison, Nina H. Leavins, James C. Croll, Bharath Krishnan, Patrick Neary

INTRODUCTION
Controversy exists in the literature whether or not muscle metabolism is altered in chronic fatigue syndrome (CFS) patients.

PURPOSE
To examine the effects of incremental exercise to volitional exhaustion and recovery on muscle haemodynamics and oxygen saturation in CFS patients.We hypothesized that fatiguing exercise would demonstrate differences in comparison to healthy control (CON) subjects.

METHODS
Six CFS patients and eight physically similar CON subjects performed an incremental cycle ergometer test. The warm-up workload began at 30W for 3 min, followed by an increase to 60W for 2 min, and then 25W increments every 2 min thereafter. Total hemoglobin (tHb; μM), deoxyhemoglobin (HHb; μM), and tissue oxygenation index (TOI; %) were monitored during exercise and passive recovery (2 min) from the right vastus lateralis muscle using spatially resolved nearinfrared spectroscopy (NIRS).

RESULTS
ANCOVA from the NIRS data revealed that the CFS group had a significantly lower TOI% (58.9 ± 1.8% vs. 64.0 ± 1.2%) throughout exercise, and longer recovery time (t½; Tau) after exercise (τ = 29.5s vs. 17.7s; P<0.05). Kinetics for tHb (τ = 18.5s vs. 39.7s), and HHb (τ = 18.7s vs. 31.7s), was significantly reduced after passive recovery in the CFS patients vs. CON, respectively.

CONCLUSIONS
The reduced muscle TOI% during and after exercise in the CFS patients suggests that peripheral muscle metabolism was altered and different from CON subjects. Furthermore, the longer recovery kinetics (τ), in tHb and HHb during recovery suggests altered metabolic and hemodynamic changes in CFS, and may indicate a peripheral autonomic imbalance.

Link | PDF (Journal of Chronic Diseases and Management) [Open Access]

 

2018 study which I don't think we have a thread for. Small numbers vs healthy controls. It looks like they used Fukuda, which was their first reference, later stating in methods —

In terms of whether these were sedentary HCs —

That seems at least relatively sedentary even if we don't know the MET-mins/week. According to the governmental Australian Institute of Health and Welfare —

See also Sedentary Behavior Research Network SBRN – Terminology Consensus Project process and outcome (2017, International Journal of Behavioral Nutrition and Physical Activity)

The HCs also reported a non-zero fatigue score: "Fatigue Severity Scale (CFS: 59±5; CON: 27±15; p<0.05)"

 

A relatively recent study in ME/CFS patients is Muscle Haemodynamics and Oxygen Saturation during Exercise and Recovery in Chronic Fatigue Syndrome Patients (2018, Journal of Chronic Diseases and Management)

That shows differences to sedentary controls. TOI is tissue oxygenation index, another term for tissue saturation index (TSI) and muscle oxygen saturation (SmO2) all interchangeable terms used in the literature I believe.

Where I think a wearable device like the Moxy Monitor could be useful is looking at what happens in the 24-48 hours after exercise. I think exercise studies to date have only looked at the exercise and immediate post-exercise recovery phase.

Also we can look more easily at moderate and severe patients who could not do an exercise challenge.