Exercise-Based Interventions
Several systematic reviews have documented fitness, health, and subjective well-being as benefits of routine physical activity for adults with SCI (Neefkes-Zonneveld et al. 2015; Tomasone et al. 2013; van der Scheer et al. 2017; Martin-Ginis et al. 2009). Exercise guidelines for adults with SCI have been established with levels of activity that are shown to improve cardiorespiratory fitness and muscle strength (Martin-Ginis et al. 2018). However, no systematic reviews about the effects or benefits of physical activity/exercise for fatigue have been done on people with SCI. Individualized and regular exercise and cognitive behavioral therapy are usually recommended for the management of fatigue in the general population (Rosenthal et al. 2008; Dukes et al. 2021).
Discussion
Exercise-based intervention studies that assessed fatigue outcomes in people with SCI included a moderate-intensity arm-crank home exercise program (Nightingale et al. 2018), two virtual reality (VR) exercise programs (Jorjafaki et al. 2022; Azurdia et al. 2022), a hybrid (FES-leg cycling combined with arm ski ergometer) high-intensity interval training (HIIT) protocol (Vestergaard et al. 2022), a seated Tai Chi Chih program (Shem et al. 2016), and a modified Yoga program (Curtis et al. 2015).
Virtual Reality Exercise-based Interventions
The most recent RCT by Jorjafaki et al. (2022) divided 45 veterans with chronic paraplegia who were experiencing fatigue into an upper limb VR exercise-based program (3x/week for 50 minutes), a reflexology program (3x/week for 30 minutes), or a control group (Jorjafaki et al. 2022). After six weeks, participants in both the VR exercise and the reflexology groups experienced significant reductions in fatigue compared to the control group, but they were not significantly different from each other (Jorjafaki et al. 2022). An additional pre-post study assessed one 6-minute arm ergometry VR exercise session and collected participant responses on pain and fatigue, and found statistically significant reductions in both, though the study only included 11 people with SCI (Azurdia et al. 2022).
We found mixed results for VR exercise programs in other clinical populations. Cho & Sohng (2014) assessed the effects of a VR exercise program, using Nintendo’s Wii Fit Plus for 40 minutes, three times a week for eight weeks, versus usual care in patients with hemodialysis and end-stage renal failure. After the program, only the experimental group showed a significant decrease in fatigue and a significant increase in physical fitness and body composition (Cho & Sohng 2014). However, a similar prospective study by Saladino et al. (2023) comparing a 12-week VR exergames program versus usual care in people with MS observed no differences in fatigue between groups.
Home-Based Exercise Intervention at Moderate Intensity
An RCT by Nightingale et al. (2018) divided 21 non-physically-active participants with chronic paraplegia to receive either a home-based arm-crank exercise program at moderate intensity, or to maintain their sedentary behavior. After six weeks of the intervention, fatigue severity (measured by the FSS) was significantly reduced in the intervention group, with a large effect size (Cohen’s d=-0.99; 90% CI= -1.75, -0.22). Meanwhile global fatigue (measured by the VAS) did not significantly change between or within-groups (Nightingale et al. 2018). Significant positive results were also shown in changes in health-related quality of life outcomes (e.g., physical component scores of the SF-36), exercise self-efficacy, physical activity, and fitness; favoring the intervention group with moderate to large effect sizes (d=0.62-1.37) (Nightingale et al. 2018).
Of note, this study was the only one included in this chapter which provided the exercise program in a home environment (Nightingale et al. 2018). This is of interest, considering that lack of access to gym facilities and exercise equipment, as well as poor information and support, have been identified as key barriers to exercise for adults with SCI (Fekete & Rauch 2012; Stephens et al. 2012; Williams et al. 2014).
The results of the RCT by Nightingale et al. (2018) agree with the recommendations of exercise prescription for patients with multiple sclerosis, where low to moderate-intensity exercise is recommended for the improvement of fatigue (Halabchi et al. 2017) and with the positive results of the implementation of a home exercise program in populations such as men with prostate cancer on androgen deprivation (Alibhai et al. 2024) or systemic sclerosis (Sari et al. 2024).
High-Intensity Exercise Interventions
One pre-post and feasibility study included eight participants with chronic paraplegia who performed a hybrid HIIT protocol, in the form of FES leg cycling combined with arm ski ergometer, three times per week (Vestergaard et al. 2022). After eight weeks, participants reported increased leisure time physical activity and health‐related quality of life, and reduced fatigue; however, the nature of this feasibility study did not support statistical analysis (Vestergaard et al. 2022). The study was deemed feasible because of high safety, acceptable attendance rate, and limited drop out (Vestergaard et al. 2022).
The recent systematic review and meta-analysis by Peters et al. (2021) has shown the benefits of HIIT for cardiovascular function in people with SCI (Peak Oxygen Uptake [VO2peak], standardized mean difference [SMD]=0.81; 95% CI 0.23-1.39; p<0.01 and Peak Power Output, SMD=0.91; 95% CI 0.32-1.5; p<0.01) (Peters et al. 2021). Additionally, different systematic reviews have shown that high-intensity exercise interventions could decrease fatigue in people with cancer (Chen et al. 2023; Wang et al. 2023) or multiple sclerosis (Youssef et al. 2024). Larger and higher quality studies need to be conducted with people with SCI to determine if HIIT has the same positive results in terms of fatigue.
Yoga and Tai Chi Exercise Interventions
Other pre-post studies conducted a modified yoga (Curtis et al. 2015) or a seated Tai Chi (Shem et al. 2016) program for people with chronic SCI. It should be noted that these two studies were the only ones that included participants with tetraplegia and paraplegia. Neither intervention revealed positive results for fatigue (Curtis et al. 2015; Shem et al. 2016).
We found systematic reviews for yoga and for Tai Chi that measured fatigue in similar populations. Positive effects on fatigue were shown in patients with cancer undergoing chemotherapy and/or radiotherapy (Ma et al. 2023), in patients with breast cancer (Hou et al. 2024), and in patients with multiple sclerosis (Shohani et al. 2020). We found one meta-analysis by Xiang et al. (2017) that found Tai Chi improved fatigue in people with cancer (SMD:-0.38, 95% CI: -0.65, -0.11); but not in people with MS (SMD:-0.77, 95% CI: -1.76, 0.22). Overall, the effects of Tai Chi and yoga programs on fatigue require further study.
Relationship Between Fatigue and Physical Activity Level
A previous systematic review and meta-analysis on factors associated with fatigue found that physical activity was inversely associated with fatigue, (r=0.17; 95% CI, 0.28, 0.05; I2=75.5; p<0.001), and was more often reported in people with SCI who ambulate and/or use their wheelchair less than 50% of the time (Onate-Figuérez et al. 2023). As previously detailed, several systematic reviews have documented fitness, health, quality of life, and subjective well-being benefits of routine physical activity participation for adults with SCI, and are antithetical to feelings of fatigue, though it has not been established in the literature (Neefkes-Zonneveld et al. 2015; Tomasone et al. 2013; van der Scheer et al. 2017).
RCTs assessing the impact of exercise on fatigue are generally effective, however non-RCTs demonstrate mixed results. A cross-sectional study of 49 people with SCI who used manual wheelchairs showed that greater physical activity was associated with fewer secondary complications including fatigue, pain, and depression (Tawashy et al. 2009). When surveying people with SCI about the association between exercise and fatigue, Hammell et al. (2009) found that opinions were divided, with some believing that “exercise made you feel more fatigued” and some believing that “it made you less fatigued”.
Effects on Fatigue After Exercise Interventions in Other Populations
Overall, fatigue has been more frequently studied in multiple sclerosis than it has in SCI. In a systematic review and meta-analysis on the effectiveness of exercise on fatigue in people with multiple sclerosis, 26 studies were included and found a significant moderate effect of exercise on fatigue, though with significant heterogeneity between studies (SMD=‐0.53, 95% CI= ‐0.73, ‐0.33; I2>58%, p<0.01) (Heine et al. 2015). Exercise therapy has also been suggested to be beneficial for reducing fatigue in people with chronic fatigue syndrome (White et al. 2011), people with fibromyalgia (Estévez-López et al. 2021), people who have had a stroke (Zedlitz et al. 2012), and people with or recovering from cancer (Ahlberg et al. 2003).
Research evidence measuring the influence of exercise on fatigue is better established in the general population. In a meta-analysis of 81 studies, Wender et al. (2022) found that exercise decreased feelings of fatigue with a small effect size (Hedge’s g=−0.374; 95% CI= -0.521, -0.227) and increased feelings of energy by a small-to-moderate effect size (Hedge’s g=0.415; 95% CI= 0.252, 0.578). From 12 population-based studies comparing active versus sedentary adults, Puetz (2006) found an odds ratio of 0.61 (95% CI= 0.52, 0.72) between physical activity and a reduced risk of experiencing fatigue. In addition, two reviews stated that individualized and regular exercise therapy or physical activity be recommended as part of the medical management of fatigue in the general population (Dukes et al. 2021; Rosenthal et al. 2008).
Conclusions
There is level 2 evidence (from one RCT: Jorjafaki et al. 2022) that 6 weeks of virtual reality arm-exercise sessions or 6 weeks of reflexology both decreased fatigue severity in veterans with SCI compared to a control group.
There is level 2 evidence (from one RCT: Nightingale et al. 2018) that 6 weeks of home-based, moderate-intensity arm-crank exercise significantly decreased fatigue severity and global fatigue compared to lifestyle maintenance in sedentary people with SCI.
There is level 4 evidence (from one pre-post: Vestergaard et al. 2022) that an 8-week hybrid HIIT program using FES leg cycling and arm ski ergometer, performed 3 times per week, decreased fatigue in people with chronic paraplegia.
There is level 4 evidence (from one pre-post: Shem et al. 2016) that a 12-week customized seated Tai Chi program performed once a week for 90 minutes each session, did not provide any change in fatigue in people with chronic SCI.
There is level 4 evidence (from one pre-post: Curtis et al. 2015) that an 8-week modified yoga program, performed once a week for 25-60 minutes each session, did not change fatigue severity in people with chronic SCI.
