Effect of Aerobic High-Intensity Hybrid Training on Stroke Volume and Peak Oxygen Consumption in Men with Spinal Cord Injury

Should We Use the Functional Electrical Stimulation-Cycling Exercise in Clinical Practice? Physiological and Clinical Effects Systematic Review With Meta-analysis

OBJECTIVE

To examine the evidence regarding functional electrical stimulation cycling's (FES-cycling's) physiological and clinical effects.

DATA SOURCES

The study was conducted in accordance with the preferred reporting items for systematic reviews and meta-analyses protocol. PubMed, Embase, Cochrane Review, CINAHL, Scopus, Sport Discus, and Web of Science databases were used.

STUDY SELECTION

Randomized controlled trials involving FES-cycling were included. Studies that did not involve FES-cycling in the intervention group or without the control group were excluded. Two reviewers screened titles and abstracts and then conducted a blinded full-text evaluation. A third reviewer resolved the discrepancies.

DATA EXTRACTION

Meta-analysis was performed using inverse variance for continuous data, with effects measured using the mean difference and random effects analysis models. A 95% confidence interval was adopted. The significance level was set at P<.05, and trends were declared at P=.05 to ≤.10. The I2 method was used for heterogeneity analysis. The minimal clinically important difference was calculated. Methodological quality was assessed using the risk of bias tool for randomized trials. The Grading of Recommendations Assessment, Development, and Evaluation method was used for the quality of the evidence analysis.

DATA SYNTHESIS

A total of 52 studies were included. Metabolic, cardiocirculatory, ventilatory, and peripheral muscle oxygen extraction variables presented statistical (P<.05) and clinically important differences favoring FES-cycling, with moderate-to-high certainty of evidence. It also presented statistical (P<.05) and clinically important improvements in cardiorespiratory fitness, leg and total body lean mass, power, physical fitness in intensive care (moderate-to-high certainty of evidence), and torque (low certainty of evidence). It presented a trend (P=.05 to ≤.10) of improvement in muscle volume, spasticity, and mobility (low-to-moderate certainty of evidence). It showed no difference (P>.10) in 6-minute walking distance, muscle cross-sectional area, bone density, and length of intensive care unit stay (low-to-moderate certainty of evidence).

CONCLUSIONS

FES-cycling exercise is a more intense stimulus modality than other comparative therapeutic modalities and presented clinically important improvement in several clinical outcomes.

Physiological and perceptual responses to sprint interval exercise using arm versus leg cycling ergometry

Increases in power output and maximal oxygen consumption (V ˙ O 2 max) occur in response to sprint interval exercise (SIE), but common use of "all-out" intensities presents a barrier for many adults. Furthermore, lower-body SIE is not feasible for all adults. We compared physiological and perceptual responses to supramaximal, but "non-all-out" SIE between leg and arm cycling exercise. Twenty-four active adults (mean ​± ​SD age: [25 ​± ​7] y; cyclingV ˙ O 2 max: [39 ​± ​7] mL·kg-1·min-1) performed incremental exercise using leg (LCE) and arm cycle ergometry (ACE) to determineV ˙ O 2 max and maximal work capacity (Wmax). Subsequently, they performed four 20 ​s bouts of SIE at 130% Wmax on the LCE or ACE at cadence ​= ​120-130 ​rev/min, with 2 ​min recovery between intervals. Gas exchange data, heart rate (HR), blood lactate concentration (BLa), rating of perceived exertion (RPE), and affective valence were acquired. Data showed significantly lower (p ​< ​0.001) absolute mean ([1.24 ​± ​0.31] L·min-1 vs. [1.59 ​± ​0.34] L·min-1; d ​= ​1.08) and peakV ˙ O 2 ([1.79 ​± ​0.48] L·min-1 vs. [2.10 ​± ​0.44] L·min-1; d ​= ​0.70) with ACE versus LCE. However, ACE elicited significantly higher (p ​< ​0.001) relative mean ([62% ​± ​9%]V ˙ O 2 max vs. [57% ​± ​7%]V ˙ O 2 max, d ​= ​0.63) and peakV ˙ O 2 ([88% ​± ​10%]V ˙ O 2 max vs. [75% ​± ​10%]V ˙ O 2 max, d ​= ​1.33). Post-exercise BLa was significantly higher ([7.0 ​± ​1.7] mM vs. [5.7 ​± ​1.5] mM, p ​= ​0.024, d ​= ​0.83) for LCE versus ACE. There was no significant effect of modality on RPE or affective valence (p ​> ​0.42), and lowest affective valence recorded (2.0 ​± ​1.8) was considered "good to fairly good". Data show that non "all-out" ACE elicits lower absolute but higher relative HR andV ˙ O 2 compared to LCE. Less aversive perceptual responses could make this non-all-out modality feasible for inactive adults.

The Clinical Management of Electrical Stimulation Therapies in the Rehabilitation of Individuals with Spinal Cord Injuries

Background: People with spinal cord injuries (SCIs) often have trouble remaining active because of paralysis. In the past, exercise recommendations focused on the non-paralyzed muscles in the arms, which provides limited benefits. However, recent studies show that electrical stimulation can help engage the paralyzed extremities, expanding the available muscle mass for exercise. Methods: The authors provide an evidence-based approach using expertise from diverse fields, supplemented by evidence from key studies toward the management of electrical stimulation therapies in individuals with SCIs. Literature searches were performed separately using the PubMed, Medline, and Google Scholar search engines. The keywords used for the searches included functional electrical stimulation cycling, hybrid cycling, neuromuscular electrical stimulation exercise, spinal cord injury, cardiovascular health, metabolic health, muscle strength, muscle mass, bone mass, upper limb treatment, diagnostic and prognostic use of functional electrical stimulation, tetraplegic hands, and hand deformities after SCI. The authors recently presented this information in a workshop at a major rehabilitation conference. Additional information beyond what was presented at the workshop was added for the writing of this paper. Results: Functional electrical stimulation (FES) cycling can improve aerobic fitness and reduce the risk of cardiovascular and metabolic diseases. The evidence indicates that while both FES leg cycling and neuromuscular electrical stimulation (NMES) resistance training can increase muscle strength and mass, NMES resistance training has been shown to be more effective for producing muscle hypertrophy in individual muscle groups. The response to the electrical stimulation of muscles can also help in the diagnosis and prognosis of hand dysfunction after tetraplegia. Conclusions: Electrical stimulation activities are safe and effective methods for exercise and testing for motor neuron lesions in individuals with SCIs and other paralytic or paretic conditions. They should be considered part of a comprehensive rehabilitation program in diagnosing, prognosing, and treating individuals with SCIs to improve function, physical activity, and overall health.

The effects of hybrid functional electrical stimulation interval training on aerobic fitness and fatigue in people with advanced multiple sclerosis: An exploratory pilot training study

BACKGROUND

Improving aerobic fitness in people with advanced multiple sclerosis (MS) may reduce fatigue, and lower the risk of cardiovascular disease, as has been found for people with mild to moderate MS. Training targeting aerobic fitness can be challenging due to paresis, access to suitable equipment and fatigue. The aim of this study was to investigate whether people with advanced multiple sclerosis could perform functional electrical stimulation (FES) cycling combined with arm crank interval exercise (hybrid FES interval training) training, and its effects on aerobic fitness and fatigue.

METHODS

Hybrid FES interval training was performed 2 d/wk for 12 weeks. Each session consisted of 40 min of continuous FES cycling with arm crank intervals of 30 s work/30 s rest added concurrently for 20 min. The intensity target was a minimum of 60 % of arm crank power and 'hard' measured by rate of perceived exertion (RPE). Attendance, compliance to intensity and time targets, adverse events, and drop outs were measured. Aerobic fitness was assessed by an arm crank maximal test. Fatigue was measured via the Modified Fatigue Impact Scale (MFIS).

RESULTS

Seven participants (6 female; age 57.1 ± 7.8y; Expanded Disability Status Scale 7.1 ± 0.8) with advanced MS attended 80 ± 10.4 % of the scheduled exercise sessions and there were no adverse events or drop outs. Average RPE at the end of each training session was 15.1 ± 2.1, representing vigorous intensity exercise. Aerobic fitness did not change pre- to post-intervention (14.2 ± 5.7 to 14.8 ± 6.0 mL/kg/min [p = 0.43]), and resulted in a small effect size (ES) (0.30). The reduction in fatigue during the intervention (31.0 ± 10.4 to 21.7 ± 11.4 [p = 0.10]), resulted in a moderate to large ES (-0.77).

CONCLUSION

Hybrid FES interval training could be performed 2 days per week for 12 weeks and represented vigorous intensity exercise, but there was no change in aerobic fitness. The reduction in participants' perceptions of fatigue represented a moderate to large ES, indicating hybrid FES interval training might be suitable for people with advanced MS who need exercise equipment appropriate for their condition.

CLINICAL TRIAL REGISTRATION

This study was registered with Australian and New Zealand Clinical Trials Register (U1111-1194-2040).

Intervention Design of High-Intensity Interval Training in Individuals With Spinal Cord Injury: Narrative Review and Future Perspectives

Background

Individuals with spinal cord injury (SCI) have lower levels of physical activity compared to the nondisabled population. Exercise guidelines recommend moderate or vigorous exercise to improve cardiovascular health and reduce cardiometabolic risk factors in persons with SCI. High-intensity interval training (HIIT) is a popular exercise choice and encompasses brief periods of vigorous exercise paired with intermittent periods of recovery.

Objectives

This review describes the available literature on HIIT for individuals with SCI, including differences in protocol design and suggested areas of further investigation.

Methods

Our institution's library system performed the comprehensive search. The primary keywords and phrases used to search included spinal cord injury, high-intensity interval training, tetraplegia, paraplegia, and several other related terms.

Results

Initially 62 records were screened, and 36 were deemed outside the scope of this review. Twenty-six studies published between 2001 and 2021 fulfilled the eligibility criteria and were divided among two researchers for review and analysis. All records required persons with SCI and a standardized HIIT intervention. Study design varied widely with respect to mode of exercise, prescribed intensity, duration of performance intervals, and session duration. This variability necessitates further investigation into the specifics of a HIIT prescription and the associated outcomes for persons with SCI.

Conclusion

Standardization of HIIT protocols may lead to more robust conclusions regarding its effects on cardiorespiratory fitness as well as mitigation of cardiometabolic risk factors. Meta-analyses will eventually be needed on proper dosing and session parameters to improve cardiorespiratory fitness and cardiometabolic risk factors.

Exercise and aerobic capacity in individuals with spinal cord injury: A systematic review with meta-analysis and meta-regression

BACKGROUND

A low level of cardiorespiratory fitness [CRF; defined as peak oxygen uptake ([Formula: see text]O2peak) or peak power output (PPO)] is a widely reported consequence of spinal cord injury (SCI) and a major risk factor associated with chronic disease. However, CRF can be modified by exercise. This systematic review with meta-analysis and meta-regression aimed to assess whether certain SCI characteristics and/or specific exercise considerations are moderators of changes in CRF.

METHODS AND FINDINGS

Databases (MEDLINE, EMBASE, CENTRAL, and Web of Science) were searched from inception to March 2023. A primary meta-analysis was conducted including randomised controlled trials (RCTs; exercise interventions lasting >2 weeks relative to control groups). A secondary meta-analysis pooled independent exercise interventions >2 weeks from longitudinal pre-post and RCT studies to explore whether subgroup differences in injury characteristics and/or exercise intervention parameters explained CRF changes. Further analyses included cohort, cross-sectional, and observational study designs. Outcome measures of interest were absolute (A[Formula: see text]O2peak) or relative [Formula: see text]O2peak (R[Formula: see text]O2peak), and/or PPO. Bias/quality was assessed via The Cochrane Risk of Bias 2 and the National Institute of Health Quality Assessment Tools. Certainty of the evidence was assessed using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach. Random effects models were used in all meta-analyses and meta-regressions. Of 21,020 identified records, 120 studies comprising 29 RCTs, 67 pre-post studies, 11 cohort, 7 cross-sectional, and 6 observational studies were included. The primary meta-analysis revealed significant improvements in A[Formula: see text]O2peak [0.16 (0.07, 0.25) L/min], R[Formula: see text]O2peak [2.9 (1.8, 3.9) mL/kg/min], and PPO [9 (5, 14) W] with exercise, relative to controls (p < 0.001). Ninety-six studies (117 independent exercise interventions comprising 1,331 adults with SCI) were included in the secondary, pooled meta-analysis which demonstrated significant increases in A[Formula: see text]O2peak [0.22 (0.17, 0.26) L/min], R[Formula: see text]O2peak [2.8 (2.2, 3.3) mL/kg/min], and PPO [11 (9, 13) W] (p < 0.001) following exercise interventions. There were subgroup differences for R[Formula: see text]O2peak based on exercise modality (p = 0.002) and intervention length (p = 0.01), but there were no differences for A[Formula: see text]O2peak. There were subgroup differences (p ≤ 0.018) for PPO based on time since injury, neurological level of injury, exercise modality, and frequency. The meta-regression found that studies with a higher mean age of participants were associated with smaller changes in A[Formula: see text]O2peak and R[Formula: see text]O2peak (p < 0.10). GRADE indicated a moderate level of certainty in the estimated effect for R[Formula: see text]O2peak, but low levels for A[Formula: see text]O2peak and PPO. This review may be limited by the small number of RCTs, which prevented a subgroup analysis within this specific study design.

CONCLUSIONS

Our primary meta-analysis confirms that performing exercise >2 weeks results in significant improvements to A[Formula: see text]O2peak, R[Formula: see text]O2peak, and PPO in individuals with SCI. The pooled meta-analysis subgroup comparisons identified that exercise interventions lasting up to 12 weeks yield the greatest change in R[Formula: see text]O2peak. Upper-body aerobic exercise and resistance training also appear the most effective at improving R[Formula: see text]O2peak and PPO. Furthermore, acutely injured, individuals with paraplegia, exercising for ≥3 sessions/week will likely experience the greatest change in PPO. Ageing seemingly diminishes the adaptive CRF responses to exercise training in individuals with SCI.

REGISTRATION

PROSPERO: CRD42018104342.

Effects of Functional Electrical Stimulation Cycling Combined With Arm Cranking Exercise on Cardiorespiratory Fitness in People With Central Nervous System Disorders: A Systematic Review and Meta-analysis

OBJECTIVE

To examine the evidence regarding the potential of hybrid functional electrical stimulation (FES) cycling for improving cardiorespiratory fitness for people with a mobility disability related to a central nervous system (CNS) disorder.

DATA SOURCES

Nine electronic databases: MEDLINE, EMBASE, Web of Science, CINAHL, PsycInfo, SPORTDiscus, Pedro, Cochrane, and Scopus, were searched from inception until October 2022.

STUDY SELECTION

Search terms included multiple sclerosis, spinal cord injury (SCI), stroke, Parkinson's disease, cerebral palsy, synonyms of FES cycling, arm crank ergometry (ACE) or hybrid exercise, and V̇o2. All experimental studies, including randomized controlled trials that included an outcome measure related to peak or sub-maximal V̇o2 were eligible.

DATA EXTRACTION

From a total of 280 articles, 13 were studies included. The Downs and Black Checklist was used to assess study quality. Random effects (Hedges' g) meta-analyses were undertaken to determine whether there were differences in V̇o2peak during acute bouts of hybrid FES cycling vs other modes of exercise and changes resulting from longitudinal training.

DATA SYNTHESIS

During acute bouts of exercise, hybrid FES cycling was moderately more effective than ACE (effect size [ES] of 0.59 (95% CI 0.15-1.02, P=.008) in increasing V̇o2peak from rest. There was a large effect on the increase of V̇o2peak from rest for hybrid FES cycling compared with FES cycling (ES of 2.36 [95% CI 0.83-3.40, P=.003]). Longitudinal training with hybrid FES cycling showed a significant improvement in V̇o2peak from pre to post intervention with a large, pooled ES of 0.83 (95% CI 0.24-1.41, P=.006).

CONCLUSIONS

Hybrid FES cycling produced higher V̇o2peak compared with ACE or FES cycling during acute bouts of exercise. Hybrid FES cycling can improve cardiorespiratory fitness in people with SCI. Additionally, there is emerging evidence that hybrid FES cycling might increase aerobic fitness in people with mobility disability related to CNS disorders.

At-Home High-Intensity Interval Training for Individuals with Paraplegia Following Spinal Cord Injury: A Pilot Study

Objective

This pilot study aimed to assess the efficacy of a 16-week at-home high-intensity interval training (HIIT) program among individuals with spinal cord injury (SCI).

Methods

Eight individuals (age: 47±11 (SD) years, 3 females) with SCI below the sixth thoracic vertebrae participated in a 16-week at-home HIIT program using an arm ergometer. Participants completed baseline graded exercise tests to determine target heart rate zones. HIIT was prescribed thrice per week. Each training session consisted of six one-minute bouts with a target heart rate ~80% heart rate reserve (HRR), interspersed with two minutes of recovery at ~30% HRR. A portable heart rate monitor and phone application provided visual feedback during training and allowed for measurements of adherence and compliance. Graded exercise tests were completed after 8 and 16 weeks of HIIT. Surveys were administered to assess participation, self-efficacy, and satisfaction.

Results

Participants demonstrated a decrease in submaximal cardiac output (P=0.028) and an increase in exercise capacity (peak power output, P=0.027) following HIIT, indicative of improved exercise economy and maximal work capacity. An 87% adherence rate was achieved during the HIIT program. Participants reached a high intensity of 70% HRR or greater during ~80% of intervals. The recovery HRR target was reached during only ~35% of intervals. Self-reported metrics of satisfaction and self-efficacy with at-home HIIT scored moderate to high.

Conclusion

Participants demonstrated an improvement in exercise economy and maximal work capacity following at-home HIIT. Additionally, participant adherence, compliance, satisfaction, and self-efficacy metrics suggest that at-home HIIT was easily implemented and enjoyable.

Post-processing Peak Oxygen Uptake Data Obtained During Cardiopulmonary Exercise Testing in Individuals With Spinal Cord Injury: A Scoping Review and Analysis of Different Post-processing Strategies

OBJECTIVES

To review the evidence regarding the most common practices adopted with cardiopulmonary exercise testing (CPET) in individuals with spinal cord injury (SCI), with the following specific aims to (1) determine the most common averaging strategies of peak oxygen uptake (V̇o2peak), (2) review the endpoint criteria adopted to determine a valid V̇o2peak, and (3) investigate the effect of averaging strategies on V̇o2peak values in a convenience sample of individuals with SCI (between the fourth cervical and sixth thoracic spinal segments).

DATA SOURCES

Searches for this scoping review were conducted in MEDLINE (PubMed), EMBASE, and Web Science.

STUDY SELECTION

Studies were included if (1) were original research on humans published in English, (2) recruited adults with traumatic and non-traumatic SCI, and (3) V̇o2peak reported and measured directly during CPET to volitional exhaustion. Full-text review identified studies published before April 2021 for inclusion.

DATA EXTRACTION

Extracted data included authors name, journal name, publication year, participant characteristics, and comprehensive information relevant to CPET.

DATA SYNTHESIS

We extracted data from a total of 197 studies involving 4860 participants. We found that more than 50% of studies adopted a 30-s averaging strategy. A wide range of endpoint criteria were used to confirm the attainment of maximal effort. In the convenience sample of individuals with SCI (n=30), the mean V̇o2peak decreased as epoch (ie, time) lengths increased. Reported V̇o2peak values differed significantly (P<.001) between averaging strategies, with epoch length explaining 56% of the variability.

CONCLUSIONS

The adoption of accepted and standardized methods for processing and analyzing CPET data are needed to ensure high-quality, reproducible research, and inform population-specific normative values for individuals with SCI.

Home-based exergaming training effects for two individuals with spinal cord injury: A case report

INTRODUCTION

Exergaming is a type of serious game that requires active bodily movements for video gameplay. This game-based exercise is gaining interest as a form of leisure activity of moderate-vigorous dose intensity.

OBJECTIVE

This case report sought to assess the effects of exergaming training (i.e. Move Boxing, Move Tennis, and Move Gladiator Duel) on aerobic capacity, feasibility, enjoyment and motivation in two individuals with spinal cord injury (SCI).

CASE DESCRIPTIONS

Two males with SCI at the level of L4 and T10, aged 32 and 39, respectively, underwent home-based exergaming training sessions over a period of 12-18 weeks, conducted within moderate-vigorous intensity training zones for health improvements as recommended by health guidelines. Their peak oxygen consumption (VO₂), physical activity levels and perceived enjoyment were evaluated before, during and after the completion of the training.

OUTCOMES

Participant peak VO₂ improved (effect size g = 2.7) from their baseline values (Participant A: 16.0 ± 0.7 mL/kg/min to 41.7 ± 8.1 mL/kg/min; Participant B: 13.5 ± 0.8 mL/kg/min to 32.7 ± 5.2 mL/kg/min), with an increase in overall weekly physical activity levels. Both participants maintained a relatively high level of enjoyment scores throughout their training period (mean: 31.9 ± 3.2, p = .56, 95% CI 0.22-1.0).

CONCLUSION

A home-based exergaming training program improved aerobic capacity and level of physical activity, while maintaining adherence to the exercise within a relatively high perception of enjoyment for these two participants. The relatively high enjoyment scores maintained throughout the duration of the exergaming training period suggested its feasibility as a home-based exercise program and perceived as enjoyable by these individuals.

Change in Central Cardiovascular Function in Response to Intense Interval Training: A Systematic Review and Meta-analysis

INTRODUCTION

High-intensity interval training and sprint interval training significantly increase maximal oxygen uptake (V̇O 2max ), which enhances endurance performance and health status. Whether this response is due to increases in central cardiovascular function (cardiac output (CO) and blood volume) or peripheral factors is unknown.

PURPOSE

This study aimed to conduct a systematic review and meta-analysis to assess the effects of high-intensity interval training and sprint interval training (referred to as intense interval training) on changes in central cardiovascular function.

METHODS

We performed a systematic search of eight databases for studies denoting increases in V̇O 2max in which CO, stroke volume (SV), blood volume, plasma volume, end-diastolic/systolic volume, or hematocrit were measured.

RESULTS

Forty-five studies were included in this analysis, comprising 946 men and women of various health status (age and V̇O 2max , 20-76 yr and 13-61 mL·kg -1 ·min -1 ) who performed 6-96 sessions of interval training. Results showed an increase in V̇O 2max with intense interval training that was classified as a large effect ( d = 0.83). SV ( d = 0.69), and CO ( d = 0.49) had moderate effect sizes in response to intense interval training. Of 27 studies in which CO was measured, 77% exhibited significant increases in resting CO or that obtained during exercise. Similarly, 93% of studies revealed significant increases in SV in response to intense interval training. Effect sizes for these outcomes were larger for clinical versus healthy populations. Plasma volume, blood volume, and hematocrit had small effect sizes after training ( d = 0.06-0.14).

CONCLUSIONS

Increases in V̇O 2max demonstrated with intense interval training are attendant with increases in central O 2 delivery with little contribution from changes in hematocrit, blood volume, or plasma volume.

Benefits and interval training in individuals with spinal cord injury: A thematic review

BACKGROUND

Arm crank ergometry (ACE), functional electrical stimulation leg cycling exercise (FES-LCE), and the combination of the two (FES hybrid exercise) have all been used as activities to help improve the fitness-related health of individuals with spinal cord injury (SCI). More recently, high-intensity interval training (HIIT) has become popular in the non-disabled community due to its ability to produce greater aerobic fitness benefits or equivalent benefits with reduced time commitment.

OBJECTIVE

This thematic review of the literature sought to determine the potential benefits and practicality of using ACE, FES-LCE, and FES hybrid exercise in an interval training format for individuals with SCI.

METHODS

Systematic literature searches were conducted in May 2020 and March 2021 focusing on interval training in individuals with SCI. Pre-defined nested search terms were used to narrow the available literature from 4273 citations to 1362 articles. The titles and abstracts were then reviewed to determine the appropriateness of the articles ending with fifteen articles.

RESULTS

The literature was limited to fifteen articles with low participant numbers (n = 1-20). However, in each article, HIIT protocols either demonstrated a greater improvement in cardiovascular, metabolic, or practicality scores compared to moderate intensity continuous training (MICT) protocols, or improvement during relatively brief time commitments.

CONCLUSION

The available literature lacked sufficient numbers of randomized control trials. However, the available evidence is encouraging concerning the potential benefits and practicality of using HIIT (ACE, FES-LCE, or FES hybrid exercise) to improve aerobic and anaerobic capacity and decrease cardiometabolic risk after SCI.

Hybrid high-intensity interval training using functional electrical stimulation leg cycling and arm ski ergometer for people with spinal cord injuries: a feasibility study

Aim

The aim was to assess safety and feasibility of Hybrid High-Intensity Interval Training (HIIT) using Functional Electrical Stimulation (FES) leg cycling and arm ski ergometer in people with Spinal Cord Injuries (SCI).

Method

Eight outpatients (mean age 42.8 years; 7 men) with stable SCI paraplegia (mean 14.5 years since injury) participated in hybrid HIIT (90% peak watts; 4 × 4–min intervals), three times a week (over 8 weeks). Primary outcomes were Adverse Events (AE), participant acceptability, shoulder pain, training intensity (% peak watts), and attendance.

Secondary outcomes were effect on peak oxygen uptake (VO₂peak) during FES hybrid poling, mean watts, self-reported leisure time physical activity, quality of life, and fatigue.

Results

No serious AE occurred; acceptability with the training modality was high, while shoulder pain increased by 9% (SD 95.2). During training, 50% of the participants reached > 90% peak watts during the intervals, three with the legs (FES cycle) and one with the arms (Ski-Erg). Overall, mean training intensity (% peak watts) was 92% (SD 18.9) for legs and 82% (SD 10.3) for arms. Proportion of fulfilled training minutes was 82% (range 36–100%); one participant dropped out after 6 weeks due to back pain. Mean VO₂peak increased by 17% (SD 17.5). Participants reported increased leisure time physical activity and health-related quality of life, besides reduced fatigue.

Conclusion

Hybrid HIIT was safe for people with SCI paraplegia. The majority of the criteria for feasibility were met with acceptable attendance rate, limited drop out, participants enjoyed training, and increased VO₂peak and mean watts. However, the intensity of 90% peak watts was reached by < 60% of the participants despite high RPE ratings during training. The method of measuring and calculating intensity needs to be studied further before a study using this HIIT protocol is undertaken.

Trial registration

Clinicaltrials.gov, NCT04211311, registered 12 December 2019 retrospectively registered

Supplementary Information

The online version contains supplementary material available at 10.1186/s40814-022-00997-2.

Effect of hybrid FES exercise on body composition during the sub-acute phase of spinal cord injury

OBJECTIVES

To determine the Effect of Hybrid functional electrically stimulated (FES) Exercise on Body Composition during the Sub-acute Phase of Spinal Cord Injury (SCI).

DESIGN

Randomized Clinical Trial.

SETTING

Rehabilitation Hospital.

PARTICIPANTS

Patients within sub-acute phase (3-24 months) of SCI.

INTERVENTIONS

We investigated if high-intensity exercise training via the addition of functional electrically stimulated (FES) leg muscles, provides sufficient stimulus to mitigate against body composition changes in the sub-acute phase after SCI.

MAIN OUTCOME MEASURES

We explored potential effects of FES row training (FESRT) on body fat gain, lean mass loss, and cardiometabolic parameters and compared the effects of 6-month of FESRT (n = 18) to standard of care (SOC, n = 13). Those in SOC were crossed over to FESRT.

RESULTS

FESRT resulted in greater exercise capacity and a tendency for lesser total body fat accumulation with a significant increase in total and leg lean mass (p<0.05). In addition pelvis and total bone mineral density declines were significantly less (p<0.05). Compared to SOC, FESRT did not lead to any significant difference in insulin sensitivity or serum lipids. However, HbA1C levels were significantly decreased in SOC participants who crossed over to 6-month FESRT.

CONCLUSION

FESRT early after SCI provides a sufficient stimulus to mitigate against detrimental body composition changes. This may lead to prevention of losses in lean mass, including bone.

Differences in Physiological and Perceptual Responses to High Intensity Interval Exercise Between Arm and Leg Cycling

This study compared changes in oxygen uptake (VO₂), heart rate (HR), blood lactate concentration (BLa), affective valence, and rating of perceived exertion (RPE) between sessions of high intensity interval exercise (HIIE) performed on the arm (ACE) and leg cycle ergometer (LCE). Twenty three active and non-obese men and women (age and BMI=24.7±5.8year and 24.8±3.4kg/m²) initially underwent graded exercise testing to determine VO₂max and peak power output (PPO) on both ergometers. Subsequently on two separate days, they performed 10 1min intervals of ACE or LCE at 75 %PPO separated by 1min of active recovery at 10 %PPO. Gas exchange data, HR, and perceptual responses were obtained continuously and blood samples were acquired pre- and post-exercise to assess the change in BLa. VO₂max and PPO on the LCE were significantly higher (p<0.001) than ACE (37.2±6.3 vs. 26.3±6.6ml/kg/min and 259.0±48.0 vs. 120.0±48.1W). Mean VO₂ (1.7±0.3 vs. 1.1±0.3L/min, d=2.3) and HR (149±14 vs. 131±17 b/min, d=2.1) were higher (p<0.001) in response to LCE vs. ACE as was BLa (7.6±2.6 vs. 5.3±2.5mM, d=2.3), yet there was no difference (p=0.12) in peak VO₂ or HR. Leg cycling elicited higher relative HR compared to ACE (81±5 vs. 75±7 %HRmax, p=0.01), although, there was no difference in relative VO₂ (63±6 vs. 60±8 %VO₂max, p=0.09) between modes. Affective valence was lower during LCE vs. ACE (p=0.003), although no differences in enjoyment (p=0.68) or RPE (p=0.59) were demonstrated. Overall, HIIE performed on the cycle ergometer elicits higher relative heart rate and blood lactate concentration and a more aversive affective valence, making these modes not interchangeable in terms of the acute physiological and perceptual response to interval based exercise.

Does aerobic exercise benefit persons with tetraplegia from spinal cord injury? A systematic review

CONTEXT

This review synthesizes the findings of previous research studies on the cardiovascular and metabolic benefits of aerobic exercise for individuals with tetraplegia secondary to spinal cord injury. They are often less active due to muscular paralysis, sensory loss, and sympathetic nervous system dysfunction that result from injury. Consequently, these persons are at higher risk for exercise intolerance and secondary health conditions.

OBJECTIVE

To evaluate the evidence concerning efficacy of aerobic exercise training for improving health and exercise performance in persons with tetraplegia from cervical injury.

METHODS

The search engines PubMed and Google Scholar were used to locate published research. The final 75 papers were selected on the basis of inclusion criteria. The studies were then rank-ordered using Physiotherapy Evidence Database.

RESULTS

Studies combining individuals with tetraplegia and paraplegia show that voluntary arm-crank training can increase mean peak power output by 33%. Functional electrical stimulation leg cycling was shown to induce higher peak cardiac output and stroke volume than arm-crank exercise. A range of peak oxygen uptake (VO_2peak) values have been reported (0.57-1.32 L/min). Both VO_2peak and cardiac output may be enhanced via increased muscle pump in the legs and venous return to the heart. Hybrid exercise (arm-crank and functional electrical stimulation leg cycling) can result in greater peak oxygen uptake and cardiovascular responses.

CONCLUSION

Evidence gathered from this systematic review of literature is inconclusive due to the lack of research focusing on those with tetraplegia. Higher power studies (level 1-3) are needed with the focus on those with tetraplegia.

The effectiveness of vigorous training on cardiorespiratory fitness in persons with spinal cord injury: a systematic review and meta-analysis

DESIGN

Systematic review and meta-analysis.

BACKGROUND AND PURPOSE

Traditional forms of upper-body moderate intensity exercise consistently provide little cardiovascular benefits for persons with spinal cord injury (PwSCI). Explorations of new training methods are vital to improve cardiovascular fitness among PwSCI. This study sought to evaluate the effectiveness of vigorous training on cardiorespiratory fitness in PwSCI.

METHODS

Database search through PubMed, Web of Science, Scopus, SportDiscus, and Cumulative Index of Nursing and Allied Health Literature (CINAHL) was conducted from the databases' inception to November 2020 to identify relevant exercise studies with PwSCI. Two independent reviewers screened articles for inclusion. Data were extracted from included studies and methodological quality evaluated.

RESULTS

Sixteen trials (eight pre-post trials and eight controlled trials [CTs]) with a total of 145 participants were analyzed. Results from pre-post studies revealed significant improvements in cardiorespiratory fitness following high-intensity interval training (HIIT) (Peak Oxygen Uptake [VO_2peak], standardized mean difference [SMD] = 0.81; 95% CI 0.23-1.39; P < 0.01 and Peak Power Output [PPO], SMD = 0.91; 95% CI 0.32-1.5; P < 0.01) and circuit resistance training (CRT) (VO_2peak, MD = 0.38; 95% CI 0.19-0.57; P < 0.01 and PPO, MD = 20.17; 95% CI 8.26-32.08; P < 0.01). Meta-analysis of CTs did not demonstrate significant improvements in cardiorespiratory fitness following vigorous training interventions in comparison to lower intensity training interventions.

CONCLUSION

Evidence from HIIT and CRT interventions suggest benefits for cardiovascular functions; however, vigorous training was not more beneficial than other forms of endurance training. More CTs are needed to better understand the effectiveness of vigorous training on cardiorespiratory fitness in PwSCI.

The Effectiveness of Active Rehabilitation Camp on Physical Performance of Disabled People Moving in Wheelchairs

(1) Background: Regular participation in physical activity (PA) prevents many medical complications and improves the physical fitness of people with spinal cord injury, and in turn improves the functional independence, psychosocial status and quality of life. The goal of Active Rehabilitation Camps (ARCs) is to use various forms of PA in order for the participants to obtain the greatest efficiency and independence in everyday life. (2) Purpose: To evaluate the improvement in physical performance of people with chronic spinal cord disabilities moving in wheelchairs taking part in the Active Rehabilitation Camp depending on (a) sex, (b) type of disability, (c) the level of injury and (d) the type of wheelchair. (3) Methods: The study included 42 wheelchair users: 28 men and 14 women aged 18-65 years (34.7 ± 14.9 years) taking part in the Active Rehabilitation Camp. Finally, the study involved 27 paraplegics, 9 tetraplegics and 6 individuals with myelomeningocele. The participants took part in four fitness tests: (1) sprint test (SP)-individual time to cover a distance of 15 m in the wheelchair; (2) slalom test (SL)-time to ride between four cones front and back; (3) basketball ball throw at a distance (BT), (4) zig-zag test (ZZ)-riding continuously for 6 min on the designated track. The tests were performed at the beginning and at the end of the ACR. Active wheelchairs were used by 32 participants, and 10 participants used the classic wheelchairs. (4) Results: Paraplegics achieved the best average results in all the tests and the best improvement in physical performance in comparison to individuals with myelomeningocele and tetraplegics. People in active wheelchairs achieved a statistically significant improvement in the results of SL and ZZ (p < 0.001). People with injury above Th-9 level of the spinal cord achieved a statistically significant improvement in the results of SP (p < 0.01), SL and ZZ (p < 0.01). People with injury below Th6 achieved a statistically significant improvement (p < 0.05) in SP, SL and ZZ. (5) Conclusions: Regular PA during the Active Rehabilitation Camp improves the physical performance of disabled people in wheelchairs, but the scale of improvement of physical performance fitness depends on the type of wheelchair used and the level and the type of injury.

Cardiac, Autonomic, and Cardiometabolic Impact of Exercise Training in Spinal Cord Injury: A QUALITATIVE REVIEW

INTRODUCTION

Direct and indirect effects of spinal cord injury lead to important cardiovascular (CV) complications that are further increased by years of injury and the process of "accelerated aging." The present review examines the current evidence in the literature for the potential cardioprotective effect of exercise training in spinal cord injury.

REVIEW METHODS

PubMed and Web of Science databases were screened for original studies investigating the effect of exercise-based interventions on aerobic capacity, cardiac structure/function, autonomic function, CV function, and/or cardiometabolic markers. We compared the effects in individuals <40 yr with time since injury <10 yr with those in older individuals (≥40 yr) with longer time since injury (≥10 yr), reasoning that the two can be considered individuals with low versus high CV risk factors.

SUMMARY

Studies showed similar exercise effects in both groups (n = 31 in low CV risk factors vs n = 15 in high CV risk factors). The evidence does not support any effect of exercise training on autonomic function but does support an increased peripheral blood flow, improved left ventricular mass, higher peak cardiac output, greater lean body mass, better antioxidant capacity, and improved endothelial function. In addition, some evidence suggests that it can result in lower blood lipids, systemic inflammation (interleukin-6, tumor necrosis factor α, and C-reactive protein), and arterial stiffness. Training intensity, volume, and frequency were key factors determining CV gains. Future studies with larger sample sizes, well-matched groups of subjects, and randomized controlled designs will be needed to determine whether high-intensity hybrid forms of training result in greater CV gains.

Feasibility, acceptability, and preliminary efficacy of a handcycling high-intensity interval training program for individuals with spinal cord injury

Study Design:

Pilot non-randomized clinical trial

Objectives:

To examine the feasibility, acceptability and preliminary efficacy of performing handcycling high intensity interval training (HIIT) for six weeks in wheelchair users with spinal cord injury.

Setting:

Participant’s home

Methods:

Participants completed pre and post graded exercise stress tests, exercise surveys and six weeks of handcycling HIIT. The HIIT program consisted of two weekly, 25 minute supervised at-home sessions (2-3 min warm-up, then 10 intervals of cycling with a ratio of 1 minute work at 90% peak power output (PPO) to 1 minute recovery at 0-20% PPO, then 2-3 min cool-down). Real-time power output and heart rate were recorded via sensors and a bike computer. The sensor data were analyzed to evaluate training efficacy.

Results:

Seven of the 10 enrolled participants (70%) completed the study. All but one completed the required 12 sessions. The participants met at least one of the HIIT target intensity criteria in 76 out of 89 total sessions (85.4%) performed. Participants expressed a high level of enjoyment on the Physical Activity Enjoyment Scale, mean (SD) = 114.8 (11.3), and satisfaction with the overall experience. Five of the seven participants (71%) who completed the study felt an increase in endurance, function and health. Objective physiological changes showed mixed results.

Conclusions:

Six weeks of handcycling HIIT appears to be safe, feasible and acceptable. A longer HIIT work interval may be needed to elicit significant physiological responses. Future investigation of the feasibility and efficacy of differing HIIT parameters is needed.

Gains in aerobic capacity with whole-body functional electrical stimulation row training and generalization to arms-only exercise after spinal cord injury

STUDY DESIGN

Longitudinal study in adults (n = 27; 19-40 years old) with tetraplegic or paraplegic spinal cord injury (SCI).

OBJECTIVES

Determine physiological adaptations and generalizable fitness effects of 6 months of whole-body exercise training using volitional arm and functional electrical stimulation (FES) leg rowing.

SETTING

Outpatient hospital-based exercise facility and laboratory.

METHODS

Participants enrolled in hybrid FES-row training (FESRT) and performed peak exercise tests with arms-only (AO; baseline and 6 months) and FES rowing (baseline, 3, 6 months).

RESULTS

Participants demonstrated increased aerobic capacity (VO_2peak) after FESRT (p < 0.001, n_p² = 0.56) that tended to be higher when assessed with FES than AO rowing tests (0.15 ± 0.20 vs. 0.04 ± 0.22 L/min; p = 0.10). Changes in FES and AO VO_2peak were significantly correlated (r = 0.55; p < 0.01), and 11 individuals demonstrated improvements (>6%) on both test formats. Younger age was the only difference between those who showed generalization of training effects and those who did not (mean age 26.6 ± 5.6 vs. 32.0 ± 5.7 years; p < 0.05) but changes in FES VO_2peak correlated to time since injury in individuals <2 years post-SCI (r = -0.51, p < 0.01, n = 24). Lastly, VO_2peak improvements were greater during the first 3 months vs. months 4-6 (+7.0% vs. +3.9%; p < 0.01) which suggests early training adaptations during FESRT.

CONCLUSIONS

Gains in aerobic capacity after whole-body FESRT are better reflected during FES-row testing format. They relate to high-intensity exercise and appear early during training, but they may not generalize to equivalent increases in AO exercise in all individuals with SCI.

Viability of high intensity interval training in persons with spinal cord injury-a perspective review

Spinal cord injury (SCI) leads to loss of sensory and motor function below the level of injury leading to paralysis and limitations to locomotion. Therefore, persons with SCI face various challenges in engaging in regular physical activity, which leads to a reduction in physical fitness, increases in body fat mass, and reduced physical and mental health status. Moderate intensity continuous training (MICT) is recommended to enhance physical fitness and overall health status in this population, but it is not always effective in promoting these benefits. High intensity interval training (HIIT) has been promoted as an alternative to MICT in individuals with SCI due to its documented efficacy in healthy able-bodied individuals as well as those with chronic disease. However, the body of knowledge concerning its application in this population is limited and mostly composed of studies with small and homogeneous samples. The aim of this review was to summarize the existing literature regarding the efficacy of HIIT on changes in health- and fitness-related outcomes in this population, denote potential adverse responses to HIIT, describe how participants perceive this modality of exercise training, and identify the overall feasibility of interval training in persons with SCI.

Acute Ventilatory Support During Whole-Body Hybrid Rowing in Patients With High-Level Spinal Cord Injury: A Randomized Controlled Crossover Trial

BACKGROUND

High-level spinal cord injury (SCI) results in profound spinal and supraspinal deficits, leading to substantial ventilatory limitations during whole-body hybrid functional electrical stimulation (FES)-rowing, a form of exercise that markedly increases the active muscle mass via electrically induced leg contractions. This study tested the effect of noninvasive ventilation (NIV) on ventilatory and aerobic capacities in SCI.

METHODS

This blinded, randomized crossover study enrolled 19 patients with SCI (level of injury ranging from C4 to T8). All patients were familiar with FES-rowing and had plateaued in their training-related increases in aerobic capacity. Patients performed two FES-rowing peak exercise tests with NIV or without NIV (sham).

RESULTS

NIV increased exercise tidal volume (peak, 1.50 ± 0.31 L vs 1.36 ± 0.34 L; P < .05) and reduced breathing frequency (peak, 35 ± 7 beats/min vs 38 ± 6 beats/min; P < .05) compared with the sham test, leading to no change in alveolar ventilation but a trend toward increased oxygen uptake efficiency (P = .06). In those who reached peak oxygen consumption (Vo₂peak) criteria (n = 13), NIV failed to significantly increase Vo₂peak (1.73 ± 0.66 L/min vs 1.78 ± 0.59 L/min); however, the range of responses revealed a correlation between changes in peak alveolar ventilation and Vo₂peak (r = 0.89; P < .05). Furthermore, those with higher level injuries and shorter time since injury exhibited the greatest increases in Vo₂peak.

CONCLUSIONS

Acute NIV can successfully improve ventilatory efficiency during FES exercise in SCI but may not improve Vo₂peak in all patients. Those who benefit most seem to be patients with cervical SCI within a shorter time since injury.

TRIAL REGISTRY

ClinicalTrials.gov; Nos.: NCT02865343 and NCT03267212; URL: www.clinicaltrials.gov.

Prediction of upper extremity peak oxygen consumption from heart rate during submaximal arm cycling in young and middle-aged adults

Based on the strong linear relationship between heart rate (HR) and oxygen consumption, the Åstrand-Ryhming cycle ergometer test (Astrand and Ryhming in J Appl Physiol 7:218-221, 1954) is a widely used submaximal test to predict whole body maximal oxygen consumption ([Formula: see text]). However, a similar test predicting peak oxygen consumption ([Formula: see text]) in the upper extremities is not established, and may be very useful for individuals unable to use their lower extremities or/and if separation of upper extremity aerobic capacity is sought after. Thus, the aim of the current study was to develop a submaximal test predicting [Formula: see text] in arm-cycling. Forty-nine healthy volunteers (25 women: 38 ± 13 years; 24 men: 39 ± 12 years) tested arm-cycle [Formula: see text] on a protocol with 4-min, 21-W increments to exhaustion. The data were contrasted to treadmill [Formula: see text] values. Arm-cycle [Formula: see text] was 66 ± 8% of [Formula: see text] (r = 0.92, p < 0.001; women: 1.9 ± 0.4 L min^-1; men: 3.0 ± 0.7 L min^-1). Arm-cycle HR and [Formula: see text] exhibited correlations of r = 0.79 and r = 0.78 for women and men, respectively, while corresponding correlations between work rate and [Formula: see text] were r = 0.95 (women) and r = 0.89 (men) (all p < 0.001). Arm-cycle [Formula: see text] prediction revealed a standard error of estimate (SEE) of 11.2% (women) and 10.2% (men), and was primarily due to individual arm-cycle maximal HR (women: 173 ± 13 beats min^-1; men: 174 ± 10 beats min^-1; correction factor: 5-7%). In conclusion, from a single 4-min stage of submaximal arm cycling, [Formula: see text] can be predicted with a SEE of 10-11%. The arm-cycle test may have important value for individuals who rely on arms in sports and occupations, and for patients with lower extremity disabilities.

Relationship of Spinal Cord Injury Level and Duration to Peak Aerobic Capacity With Arms-Only and Hybrid Functional Electrical Stimulation Rowing

OBJECTIVE

The aim of the study was to assess the relationship of spinal cord injury level and duration to peak aerobic capacities during arms-only rowing compared with hybrid Functional Electrical Stimulation (FES)-rowing.

DESIGN

Comparison of peak aerobic capacity (VO2), peak ventilation, peak respiratory exchange ratio, and peak heart rate were measured during arms-only rowing and FES-rowing obtained from graded exercise tests.

RESULTS

Peak aerobic values were strongly related to injury level and injury duration for both arms-only rowing (r = 0.67, P < 0.05) and FES-rowing (r = 0.61, P < 0.05). Peak aerobic capacities were greater across all injury levels and durations with FES-rowing compared with arms-only rowing. Differences in VO2 were inversely related to injury level (r = 0.55, P < 0.05) with greater increases in VO2 in higher level injuries. Injury durations of less than 2 yrs had greater percent increases in VO2 with FES-rowing.

CONCLUSIONS

FES-rowing acutely post injury may have the greatest effect to maintain function and improve VO2. This impact seems to be greatest in those with higher level injuries.

Effects of High-Intensity Interval Training Versus Moderate-Intensity Training on Cardiometabolic Health Markers in Individuals With Spinal Cord Injury: A Pilot Study

Background: Recent studies in nondisabled individuals have demonstrated that low-volume high-intensity interval training (HIIT) can improve cardiometabolic health similar to moderate-intensity training (MIT) despite requiring 20% of the overall time commitment. To date, there have been no studies assessing the effects of HIIT for improving cardiometabolic health in individuals with SCI. Objectives: The primary purpose of this pilot study was to compare the effects of 6 weeks of low-volume HIIT vs MIT using arm crank ergometer exercise to improve body composition, cardiovascular fitness, glucose tolerance, blood lipids, and blood pressure in a cohort of individuals with longstanding SCI. Methods: Participants were randomized to 6 weeks of HIIT or MIT arm crank exercise training. Aerobic capacity, muscular strength, blood lipids, glucose tolerance, blood pressure, and body composition were assessed at baseline and 6 weeks post training. Results: Seven individuals (6 male, 1 female; n = 3 in MIT and n = 4 in HIIT; mean age 51.3 ± 10.5 years) with longstanding SCI completed the study. The preliminary findings from this pilot study demonstrated that individuals with SCI randomized to either 6 weeks of HIIT or MIT displayed improvements in (a) insulin sensitivity, (b) cardiovascular fitness, and (c) muscular strength (p < .05). However, MIT led to greater improvements in arm fat percent and chest press strength compared to HIIT (p < .05). Conclusion: No differences between MIT and HIIT were observed. Both conditions led to improvements in insulin sensitivity, aerobic capacity, muscle strength, and blood lipids in individuals with SCI. Future larger cohort studies are needed to determine if the shorter amount of time required from HIIT is preferable to current MIT exercise recommendations.

Hemodynamic and cardiorespiratory responses to various arm cycling regimens in men with spinal cord injury

Study design

Repeated measures within-subjects crossover study.

Objectives

High intensity interval exercise (HIIE) elicits higher oxygen consumption (VO₂) and heart rate (HR) versus moderate intensity continuous exercise (MICE) in men with spinal cord injury (SCI). No study has compared hemodynamic responses to HIIE versus MICE in SCI. In this study, we determined hemodynamic and cardiorespiratory responses to different bouts of arm cycling in men with SCI.

Setting

Human Performance Laboratory, San Diego, CA.

Methods

Five men (age and injury duration = 42.6 ± 16.1 yr and 9.9 ± 7.6 yr) with SCI participated in the study. VO₂peak and peak power output were initially assessed. Subsequent visits included MICE, HIIE, sprint interval exercise (SIE), and a no-exercise control (CON). Energy expenditure was matched across modes and equal to 100 ± 10 kcal. During the bouts, cardiac output (CO), stroke volume (SV), HR, and VO₂ were measured.

Results

Heart rate, SV, and CO increased in response to all exercise bouts and were higher during exercise versus CON. During HIIE and SIE, heart rate approached 90% of maximum, and stroke volume increased by 40% which was higher (p < 0.05) versus MICE and CON. In addition, exercise led to a two (MICE) to threefold increase in CO (HIIE and SIE) although it was not different from CON. VO₂ during SIE and HIIE was higher (p < 0.05) versus MICE.

Conclusions

Similar to results in non-disabled populations, HIIE and SIE elicit near-maximal values of SV and CO.

Stimulation of paralysed quadriceps muscles with sequentially and spatially distributed electrodes during dynamic knee extension

BACKGROUND

During functional electrical stimulation (FES) tasks with able-bodied (AB) participants, spatially distributed sequential stimulation (SDSS) has demonstrated substantial improvements in power output and fatigue properties compared to conventional single electrode stimulation (SES). The aim of this study was to compare the properties of SDSS and SES in participants with spinal cord injury (SCI) in a dynamic isokinetic knee extension task simulating knee movement during recumbent cycling.

METHOD

Using a case-series design, m. vastus lateralis and medialis of four participants with motor and sensory complete SCI (AIS A) were stimulated for 6 min on both legs with both electrode setups. With SES, target muscles were stimulated by a pair of electrodes. In SDSS, the distal electrodes were replaced by four small electrodes giving the same overall stimulation frequency and having the same total surface area. Torque was measured during knee extension by a dynamometer at an angular velocity of 110 deg/s. Mean power of the left and right sides (P_meanL,R) was calculated from all stimulated extensions for initial, final and all extensions. Fatigue is presented as an index value with respect to initial power from 1 to 0, whereby 1 means no fatigue.

RESULTS

SDSS showed higher P_meanL,R values for all four participants for all extensions (increases of 132% in participant P1, 100% in P2, 36% in P3 and 18% in P4 compared to SES) and for the initial phase (increases of 84%, 59%, 66%, and 16%, respectively). Fatigue resistance was better with SDSS for P1, P2 and P4 but worse for P3 (0.47 vs 0.35, 0.63 vs 0.49, 0.90 vs 0.82 and 0.59 vs 0.77, respectively).

CONCLUSION

Consistently higher P_meanL,R was observed for all four participants for initial and overall contractions using SDSS. This supports findings from previous studies with AB participants. Fatigue properties were better in three of the four participants. The lower fatigue resistance with SDSS in one participant may be explained by a very low muscle activation level in this case. Further investigation in a larger cohort is warranted.

Interval training elicits higher enjoyment versus moderate exercise in persons with spinal cord injury

BACKGROUND

High intensity interval training (HIIT) is a robust and time-efficient approach to improve multiple health indices including maximal oxygen uptake (VO2max). Despite the intense nature of HIIT, data in untrained adults report greater enjoyment of HIIT versus continuous exercise (CEX). However, this has yet to be investigated in persons with spinal cord injury (SCI).

OBJECTIVE

To examine differences in enjoyment in response to CEX and HIIT in persons with SCI.

DESIGN

Repeated measures, within-subjects design.

SETTING

University laboratory in San Diego, CA.

PARTICIPANTS

Nine habitually active men and women (age = 33.3 ± 10.5 years) with chronic SCI.

INTERVENTION

Participants performed progressive arm ergometry to volitional exhaustion to determine VO2peak. During subsequent sessions, they completed CEX, sprint interval training (SIT), or HIIT in randomized order.

OUTCOME MEASURES

Physical activity enjoyment (PACES), affect, rating of perceived exertion (RPE), VO2, and blood lactate concentration (BLa) were measured.

RESULTS

Despite a higher VO2, RPE, and BLa consequent with HIIT and SIT (P < 0.05), PACES was significantly higher (P = 0.03) in response to HIIT (107.4 ± 13.4) and SIT (103.7 ± 12.5) compared to CEX (81.6 ± 25.4). Fifty-five percent of participants preferred HIIT and 45% preferred SIT, with none identifying CEX as their preferred exercise mode.

CONCLUSION

Compared to CEX, brief sessions of submaximal or supramaximal interval training elicit higher enjoyment despite higher metabolic strain. The long-term efficacy and feasibility of HIIT in this population should be explored considering that it is not viewed as more aversive than CEX.

Arm Cycling Combined with Passive Leg Cycling Enhances VO2peak in Persons with Spinal Cord Injury Above the Sixth Thoracic Vertebra

Objective: To test whether passive leg cycling (PLC) during arm cycling ergometry (ACE) affects peak oxygen uptake (VO2peak) differently in individuals with spinal cord injury (SCI) at/above the 6th thoracic vertebra (T6) and below T6. Methods: We conducted a cross-sectional study, analyzed by univariate and multivariate regression models. Between- and within-group differences were examined during (a) ACE only, (b) ACE combined with PLC (ACE-PLC), and (c) ACE combined with functional electrical stimulation cycling (FES hybrid). Fifteen SCI subjects were recruited and grouped according to injury level: at/above T6 (SCI-high, n = 8) or below T6 (SCI-low, n = 7). VO2peak tests during ACE only, ACE-PLC, and FES hybrid were performed in random order on separate days. Results: In the SCI-high group, mean (SD) VO2peak was 19% higher during ACE-PLC than during ACE only [21.0 (3.8) vs 17.7 (5.0) mL·kg-1·min-1; p = .002], while VO2peak during FES hybrid cycling was 16% higher than during ACE-PLC [24.4 (4.1) mL·kg-1·min-1; p = .001]. No significant differences among exercise modalities were found for the SCI-low group. Conclusion: Additional training modalities (eg, PLC) during ACE facilitate exercise in SCI-high individuals, but not to the level of the FES hybrid method. Conversely, additional training modalities may not increase training load in SCI-low individuals.

Ventilation Limits Aerobic Capacity after Functional Electrical Stimulation Row Training in High Spinal Cord Injury

PURPOSE

In the able-bodied, exercise training results in increased ventilatory capacity to meet increased aerobic demands of trained skeletal muscle. However, after spinal cord injury (SCI), peak ventilation can be limited by pulmonary muscle denervation. In fact, peak ventilation may restrict aerobic capacity in direct relation to injury level. Hybrid functional electrical stimulation (FES) exercise training results in increased aerobic capacity and dissociation between aerobic capacity and injury level in those with injuries at T3 and below. However, injuries above T3 have the greatest pulmonary denervation, and ventilatory capacity may restrict the increase in aerobic capacity with hybrid FES training.

METHODS

We assessed relationships among injury level, peak ventilation, and peak aerobic capacity and calculated oxygen uptake efficiency slope during hybrid FES exercise in 12 individuals (1 female) with SCI at level T2 to C4 (injury duration = 0.33-33 yr, age = 20-60 yr), before and after 6 months of FES-row training (FES-RT).

RESULTS

Training increased peak aerobic capacity by 12% (P = 0.02) with only a modest increase in peak ventilation (7 of 12 subjects, P = 0.09). Both before and after training, injury level was directly related to peak ventilation (R = 0.48 and 0.43) and peak aerobic capacity (R = 0.70 and 0.55). Before training, the relationship of peak aerobic capacity to peak ventilation was strong (R = 0.62), however, after training, this relationship became almost completely linearized (R = 0.84). In addition, oxygen uptake efficiency slope increased by 11% (P < 0.05) after FES-RT.

CONCLUSION

Despite the ability to increase exercise capacity via hybrid FES exercise, the inability to increase peak ventilation beyond limits set by SCI level in those with high-level injuries (above T3) appears to restrict aerobic capacity.

Within-session responses to high-intensity interval training in spinal cord injury

AIM

Completion of high-intensity interval training (HIIT) increases maximal oxygen uptake and health status, yet its feasibility in persons with spinal cord injury is unknown.

PURPOSE

To compare changes in cardiorespiratory and metabolic variables between two interval training regimes and moderate intensity exercise.

METHOD

Nine adults with spinal cord injury (duration = 6.8 ± 6.2 year) initially underwent determination of peak oxygen uptake. During subsequent sessions, they completed moderate intensity exercise, HIIT, or sprint interval training. Oxygen uptake, heart rate, and blood lactate concentration were measured.

RESULTS

Oxygen uptake and heart rate increased (p < 0.05) during both interval training sessions and were similar (p > 0.05) to moderate intensity exercise. Peak oxygen uptake and heart rate were higher (p < 0.05) with HIIT (90% peak oxygen uptake and 99% peak heart rate) and sprint interval training (80% peak oxygen uptake and 96% peak heart rate) versus moderate intensity exercise.

CONCLUSIONS

Despite a higher intensity and peak cardiorespiratory strain, all participants preferred interval training versus moderate exercise. Examining long-term efficacy and feasibility of interval training in this population is merited, considering that exercise intensity is recognized as the most important variable factor of exercise programming to optimize maximal oxygen uptake. Implications for Rehabilitation Spinal cord injury (SCI) reduces locomotion which impairs voluntary physical activity, typically resulting in a reduction in peak oxygen uptake and enhanced chronic disease risk. In various able-bodied populations, completion of high-intensity interval training (HIIT) has been consistently reported to improve cardiorespiratory fitness and other health-related outcomes, although its efficacy in persons with SCI is poorly understood. Data from this study in 9 men and women with SCI show similar changes in oxygen uptake and heart in response to HIIT compared to a prolonged bout of aerobic exercise, although peak values were higher in response to HIIT. Due to the higher peak metabolic strain induced by HIIT as well as universal preference for this modality versus aerobic exercise as reported in this study, further work testing utility of HIIT in this population is merited.

Circuit training and protein supplementation in persons with chronic tetraplegia

Circuit resistance training (CRT) performed three times weekly for 40-45 min each session increases muscular strength and both aerobic and anaerobic capacity in untrained individuals with chronic paraplegia. Whether similar CRT is also effective for conditioning of persons with chronic tetraplegia is unknown. In addition, protein supplementation (PS) before and immediately postexercise has been shown to enhance exercise adaptations.

PURPOSE

This study aimed to investigate whether a modified 40-45 min CRT program will improve fitness attributes in individuals with tetraplegia and whether these changes are enhanced by PS.

METHODS

Eleven individuals with chronic tetraplegia underwent 6 months of CRT performed three times per week. Six randomly assigned participants received PS (whey protein = 36-37 g) in split doses immediately before and after exercise sessions. Others consumed a matched protein dose 24 h postexercise. Measurements of one-repetition maximum (1-RM) strength for six different resistance exercises, arm peak oxygen consumption (VO2peak), and arm anaerobic power (Wingate) were obtained 3 months before (-3mo), at the beginning (0mo), 3 months into (3mo), and 6 months after (6mo) the beginning of CRT.

RESULTS

One-repetition maximum increased by 8%-11% ± 6%-12% for each successive 3-month period (P ≤ 0.001-0.012), independent of PS group (P = 0.105). VO2peak increased significantly from 0mo to 6mo with immediate PS (35% ± 29%, P = 0.020) but failed to reach significance for delayed PS (15% ± 8%, P = 0.147). Power drop changes during the Wingate test were also only significant for the immediate PS (median difference 40W, P = 0.028) and not for delayed (10W, P = 0.500).

CONCLUSION

CRT effectively increased muscular strength, aerobic capacity, and anaerobic fatigue resistance in persons with chronic tetraplegia. The latter two conditioning benefits were further enhanced by timely PS.

Metabolic rate and cardiorespiratory response during hybrid cycling versus handcycling at equal subjective exercise intensity levels in people with spinal cord injury

OBJECTIVE

To compare the metabolic rate and cardiorespiratory response during hybrid cycling versus handcycling at equal subjective exercise intensity levels in people with spinal cord injury (SCI).

DESIGN

Cross-sectional study.

SETTING

Amsterdam Rehabilitation Research Centre | Reade, Amsterdam, The Netherlands.

METHODS

On separate days, nine individuals with a motor complete paraplegia or tetraplegia (eight men, age 40 ± 13 years, time since injury 12 ± 10 years) performed 5-minute bouts of hybrid cycling (day 1) and handcycling (day 2) at moderate (level 3 on a 10-point rating of perceived exertion (RPE) scale) and vigorous (RPE level 6) subjective exercise intensity, while respiratory gas exchange was measured by open-circuit spirometry and heart rate was monitored using radiotelemetry.

OUTCOME MEASURES

Metabolic rate (calculated with the Weir equation) and cardiorespiratory response (heart rate, oxygen pulse, and ventilation).

RESULTS

Overall, the metabolic rate during hybrid cycling was 3.4 kJ (16%) higher (P = 0.006) than during handcycling. Furthermore, compared with handcycling, the overall heart rate and ventilation during hybrid cycling was 11 bpm (11%) and 5.3 l/minute (18%) higher (P = 0.004 and 0.024), respectively, while the oxygen pulse was the same (P = 0.26).

CONCLUSION

Hybrid cycling induces a higher metabolic rate and cardiorespiratory response at equal RPE levels than handcycling, suggesting that hybrid cycling is more suitable for fighting obesity and increasing cardiorespiratory fitness in individuals with SCI.

Hybrid functional electrical stimulation exercise training alters the relationship between spinal cord injury level and aerobic capacity

OBJECTIVE

To test the hypothesis that hybrid functional electrical stimulation (FES) row training would improve aerobic capacity but that it would remain strongly linked to level of spinal cord lesion because of limited maximal ventilation.

DESIGN

Longitudinal before-after trial of 6 months of FES row training.

SETTING

Exercise for persons with disabilities program in a hospitaL.

PARTICIPANTS

Volunteers (N=14; age range, 21-63y) with complete spinal cord injury (SCI) (T3-11) who are >2 years postinjury.

INTERVENTION

Six months of FES row training preceded by a variable period of FES strength training.

MAIN OUTCOME MEASURES

Peak aerobic capacity and peak exercise ventilation before and after 6 months of FES row training.

RESULTS

FES row training significantly increased peak aerobic capacity and peak minute ventilation (both P<.05). Prior to FES row training, there was a close relation between level of SCI and peak aerobic capacity (adjusted R(2)=.40, P=.009) that was markedly reduced after FES row training (adjusted R(2)=.15, P=.10). In contrast, the relation between level of injury and peak minute ventilation was comparable before and after FES row training (adjusted R(2)=.38 vs .32, both P<.05).

CONCLUSIONS

The increased aerobic capacity reflects more than increased ventilation; FES row training effectively circumvents the effect of SCI on peak aerobic capacity by engaging more muscle mass for training, independent of the level of injury.

Systematic framework to classify the status of research on spinal cord injury and physical activity

OBJECTIVES

To systematically classify the physical activity research for individuals with a spinal cord injury by using the behavioral epidemiologic framework; and to identify where the physical activity research for individuals with a spinal cord injury has focused between 2000 and 2012.

DESIGN

Relevant research was identified and then categorized into 1 of 5 phases by following the coding rules of the behavioral epidemiology framework. Phase 1 studies link physical activity and health outcomes, phase 2 studies validate or develop measures of physical activity, phase 3 studies identify factors that influence behavior or examine explanatory theories of behavior, phase 4 studies evaluate interventions, and phase 5 studies disseminate health promotion programs or policies and translate research into practice.

SETTING

Specific keywords were identified and then searched through EBSCOhost, PubMed, and Google Scholar.

PARTICIPANTS

Not applicable.

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

Not applicable.

RESULTS

One hundred and thirteen articles met the criteria. Of the articles, 55% were categorized as phase 1, 12% as phase 2, 24% as phase 3, 5% as phase 4, and 4% as phase 5.

CONCLUSIONS

Most studies were categorized as phase 1, 2, or 3, which implies that this field is still in the early stages of development and research should focus on intervention development and dissemination.

Effectiveness of aerobic physical training for treatment of chronic asymptomatic bacteriuria in subjects with spinal cord injury: a randomized controlled trial

Objective:

To evaluate the effectiveness and safety of aerobic physical training for treatment of chronic asymptomatic bacteriuria in subjects with spinal cord injury.

Design:

Randomized controlled trial.

Setting:

University hospital.

Subjects:

Forty-two participants with spinal cord injury between C8 and T12 segments were randomly assigned to intervention or control groups.

Intervention:

In the intervention group, subjects received a risk evaluation, stress test and urinary culture before the start of the study and after 16 weeks. The study consisted of aerobic physical conditioning with moderate intensity for the intervention group while the control group was asked to maintain their daily life activities.

Main measures:

Increase of estimated peak oxygen consumption and also if there was a decrease in the proportions of positive urinary culture.

Results:

The intervention group showed an increase of estimated peak oxygen consumption of between 939 (714–1215) and 1154 (1005–1351) mL/min ( P = 0.009) and a reduction of chronic asymptomatic bacteria of between 52.3% (29.8–74.3%) and 14.2% (3–36.3%) ( P < 0.001). No adverse effects related to physical activity were recorded during the period of training.

Conclusion:

The regular practice of physical activity of moderate intensity applied to patients with spinal cord injury may be an effective and safe method for the treatment of chronic asymptomatic bacteriuria.

Effect of leg vascular occlusion on arm cycling peak oxygen uptake in spinal cord-injured individuals

STUDY DESIGN

Cross-sectional single-subject design.

OBJECTIVES

To determine whether leg vascular occlusion (LEVO) augment arm cycling (ACE) peak oxygen uptake in spinal cord-injured individuals.

SETTING

University Hospital, Norway.

METHODS

Fifteen individuals with C(4) to T(12) spinal cord injury (SCI) were recruited and divided into two groups: injury above (SCI-high, n=8) or below (SCI-low, n=7) the T(6) level. Peak oxygen uptake (VO(2peak)) was measured during (1) ACE combined with LEVO, (2) ACE alone and (3) ACE combined with functional electrical stimulation cycling (FES hybrid cycling).

RESULTS

In the SCI-high group, VO(2peak) and peak Watt during ACE with LEVO were higher than ACE alone: 20.0 (±5.0) versus 17.6 (±5.0) ml kg(-1) min(-1) (P=0.006), and 72.5(±32) versus 80.0 (±34) Watt (P=0.016), respectively. However, FES hybrid cycling VO(2peak) was significantly higher than ACE with LEVO: 24.4 (±4.1) versus 20.0 (±5.0) ml kg(-1) min(-1) (P=0.006). In the SCI-low group, there was no difference in VO(2peak) and related parameters between the three modalities.

CONCLUSIONS

For spinal cord-injured individuals with injury level above T(6) (high) in the present study, LEVO combined with ACE augment VO(2peak). However, this acute increase in VO(2peak) was lower than when FES cycling was combined with ACE. These findings may have future implications for exercise prescription for spinal cord-injured individuals.