Low-Force Muscle Activity Regulates Energy Expenditure after Spinal Cord Injury

Abstract

Reduced physical activity is a primary risk factor for increased morbidity and mortality, People with spinal cord injury (SCI) have reduced activity for a lifetime, as they cannot volitionally activate affected skeletal muscles. We explored whether low force and low frequency stimulation is a viable strategy to enhance systemic energy expenditure in people with SCI. Purpose To determine the effects of low stimulation frequency (1 Hz, 3 Hz) and stimulation intensity (50 mA and 100 mA) on energy expenditure in people with SCI. We also examined the relationship between body mass index (BMI) and visceral adipose tissue (VAT) on energy expenditure during low frequency stimulation. Methods Ten individuals with complete SCI underwent oxygen consumption monitoring during electrical activation of the quadriceps and hamstrings at 1 Hz and 3 Hz and at 50 and 100 mA. We calculated the difference in energy expenditure between stimulation and rest and estimated the number of days that would be necessary to burn 1 pound of body fat (3,500 kcal) for each stimulation protocol (1 Hz versus 3 Hz). Results Both training frequencies induced a significant increase in oxygen consumption above a resting baseline level (p < 0.05). Energy expenditure positively correlated with stimulus intensity (muscle recruitment) and negatively correlated with adiposity (reflecting the insulating properties of adipose tissue). We estimated that 1 pound of body fat could be burned more quickly with 1 Hz training (58 days) as compared to 3 Hz training (87 days) if an identical number of pulses were delivered. Conclusion Low-frequency stimulation increased energy expenditure per pulse and may be a feasible option to subsidize physical activity to improve metabolic status after SCI.

Four weeks of electrical stimulation improves glucose tolerance in a sedentary overweight or obese Hispanic population

“…In our study, NMES treatment significantly increased blood lactate level during the duration of the stimulation, indicating an increase in glucose utilization. Similar results were also reported acutely in a T2DM population in a daily 12 week high frequency intervention [47] Copyright © 2022 the authors are more metabolically flexible [4]. It is possible that our study, despite detecting changes in blood lactate levels was not appropriately powered to detect changes in energy expenditure and whole body substrate utilization within this small sample size.…”

Energy Expenditure as a Function of Activity Level After Spinal Cord Injury: The Need for Tetraplegia-Specific Energy Balance Guidelines

“…Other strategies taken from competitive athletes to increase exercise duration may be useful, such as cooling to deal with thermoregulatory sequelae of tetraplegia ( Griggs et al, 2014 ). Finally, the use of electrical stimulation of paralyzed leg muscles for either low force contraction ( Woelfel et al, 2017 ) or higher force activities such as cycling or rowing should be considered as a necessary adjunct to voluntary exercise. The supplement of electrical stimulation-based exercise should increase energy use, decrease overall body fat and perhaps in the case of rowing, even increase cardiovascular fitness in tetraplegia ( Taylor et al, 2014 ; Gibbons et al, 2016 ; Dolbow and Credeur, 2017 ; Dolbow et al, 2017 ).…”

Energy expenditure and muscle activity during lying, sitting, standing, and walking in people with motor-incomplete spinal cord injury

“…But, activating large muscle groups is generally accepted as an interruption of sedentary behavior/time. A recent interesting study shows that low-frequency stimulation of the quadriceps and hamstrings increased EE above the resting baseline level, which might also be a feasible option to offset the negative side effects related to muscle inactivity after SCI [34].…”