Body-Weight Supported Treadmill Training (BWSTT)

Body-weight supported treadmill training (BWSTT) is an exercise protocol that involves supporting an individual over the top of a motorized treadmill with a counterbalanced harness system. The premise of all BWSTT protocols is to offset some of an individual’s body weight to reduce the work associated with upright walking, using a weight stack to adjust the magnitude of support and treadmill speed to adjust the intensity of exercise. The degree of support, as well as the amount of progression across a training period, is highly individualized, determined by a trained therapist observing proper gait and cardiovascular responses. While BWSTT has garnered attention in functional movement rehabilitation, previous studies have indicated this strategy can also target conventional outcomes of cardiorespiratory fitness through a lower-intensity aerobic challenge. While the resources for this modality are high (i.e., specialized treadmill, lead therapist, volunteers to assist with leg movements), there is potential for BWSTT to target multiple exercise domains including upright posture challenges, cardiovascular effort, and lower-limb skeletal muscle involvement.

Author Year

Research Design

Total Sample Size



Alexeeva et al. (2011)





Population: SCI Group: Sex: males=30, females=5; Age (range): 16–70 yr; injury at or rostral to T10; able to rise to standing position with moderate assistance or less, and independently advance at least one leg.

Intervention: Patients were randomized to 3 groups (body-weight-supported (BWS) walking on a fixed track vs. BWS walking on a treadmill vs. comprehensive physical therapy). The BWS groups used 30% BWS. Patients participated in a 13wk (1 hr/day, 3 d/wk) program.

Outcome measures: performance values, heart rate (HR), pre- and post-training 10-m walking speed, balance, muscle strength, fitness (VO2peak), and quality of life.

·         Participants in the ‘BWS walking on a fixed track’ group achieved the highest average heart rate during training, whereas those in physical therapy had the lowest average heart rate.

·         In all three groups there was a clinically important post-training ↑ in average normalized VO2peak (~12% in each group); however, these differences did not achieve statistical significance.


Millar et al. (2009)


RCT with crossover



Population: SCI Group: Mean age: 37.1±7.7 yr; Sex: males=6, females=1; C5-T10 level injury, AIS A-C; mean time post-injury: 5.0±4.4 yr

Intervention: Each participant underwent both BWSTT and head-up tilt training (HUTT) in random order, for 3 times/wk for 4wks, separated by a 4wk detraining period.

Outcome Measures: Heart rate variability; heart rate complexity; fractal scaling distance score (the correlation of the time between heart beats).

·         No significant difference in heart rate variability after either BWSTT or HUTT training.

·         There was ↑ sample heart rate complexity after BWSTT, whereas HUTT had no effect.

·         BWSTT, but not HUTT, reduced the fractal scaling distance score in participants.

Stevens & Morgan (2015)




Population: SCI Group: Mean age: 48 yr; Sex: males=7, females=4; 6 adults with injuries at or above T5 and 5 adults with injuries below T5.

Intervention: 8wks of Underwater Treadmill Training (UTT) (3 sessions/wk, 3 walking trials per session) incorporating individually determined walking speeds, personalized levels of body weight unloading, and gradual, alternating increases in speed and duration. In weeks 2, 4, 6, and 8, walking speed was increased by 10%, 20%, 30%, and 40% over baseline.

Outcome Measures: Heart rate

·         None of the interaction tests involving injury level were statistically significant. When averaged over injury level, the interaction between training period and day was significant.

·         Pairwise comparisons revealed that from day 1 to day 6, heart rate fell by 7%, 14%, and 17% during training periods 1, 2, and 3. All participants exhibited significant ↓ in daily submaximal walking heart rate for each 2-week period.

Terson de Paleville et al. (2013)

United States



Population: Mean age: 37 yr; Sex: males=7, females=1; AIS-A tetraplegic; Mean time post injury: 25 mo.

Intervention: Locomotor training (LT) with body weight support and treadmill 5 days/week for an average of 62 sessions.

Outcome Measures: Forced vital capacity (FVC), forced expiratory volume (FEV1), maximal inspiratory pressure (MIP), maximal expiratory pressure (MEP), respiratory muscle surface electromyography (sEMG) and respiratory motor control assessment.

·         Significantly ↑ FVC, MIP, MEP, and FEV1 post-LT compared to pre-LT.

·         Significantly ↑ overall sEMG activity post-LT for all tasks.

·         7 participants had ↑ sEMG amplitudes for all tasks post-LT.

·         No significant changes in distribution of sEMG activity post-LT for all tasks.

·         1 subject developed activation in muscles post-LT which were not activated pre-LT.

·         Significantly faster muscle unit recruitment post-LT compared to pre-LT.

Soyupek et. al. (2009)




Population: Incomplete SCI Group: Mean Age: 40. 8 ±13.9 yr (Range: 26-66 yr); Sex: males=6, females=2; Injury level C6-L1

Intervention:  Body weight supported treadmill training (BWSTT), for 5 times/wk for 6 wks; length of training sessions ranged from 10 to 30 min

Outcome Measures: Heart rate and blood pressure (BP); FEV1, FVC, inspiratory capacity, MIP, MEP.

·         Heart rate was significantly lower post-training compared to baseline.

·         There were significant improvements of the FVC and inspiratory capacity in participants post-training compared to baseline.

·         There were no significant differences in other parameters between pre- and post-training

Ditor et al. (2005)




Population: SCI Group: Mean Age: 37.7 yr; Sex: males=4, females=2; AIS A and B, C4-T12; Mean time post injury: 6.7 yr; motor complete.

Intervention: Body weight supported treadmill training, 15 min/day (3 bouts of 5 min), 3 days/wk for 4mo.

Outcome Measures: BP, HR, HR variability, BP variability, arterial diameters and mean blood velocities, and arterial blood flow.

·         No changes in femoral or carotid artery cross sectional area or blood flow post-training.

·         An improvement in femoral artery compliance post-training.

·         No change in resting BP, mean arterial blood pressure, resting HR or HR and BP variability after training.

·         3/6 patients had changes in HR and BP variability reflective of ↑ vagal dominance.

de Carvalho et al.

2006 (de Carvalho et al., 2006);



Controlled Trial

Level 2

N = 21

Population: 21 male participants (C4 to C8), all complete with tetraplegia, mean age 32 ± 8 yrs. 11 assigned to the gait group and 10 controls.

Treatment: BWSTT (30%–50%) with neuromuscular electrical stimulation 20 min/day, 2 days/wk for 6 mo. Control group performed conventional physiotherapy.

Outcome Measures: BP, HR, oxygen uptake, carbon dioxide production, and minute ventilation (volume of gas entering lungs).

·         Gait training (six months) resulted in significant ↑ in oxygen consumption (36%), minute ventilation (31%), and systolic blood pressure (5%) during the gait phase. In the control group, there were significant ↑ in resting oxygen consumption and carbon dioxide production (31 and 16%, respectively).

·         Gait training resulted in an ↑ aerobic capacity due to yielding higher metabolic and cardiovascular stress.

de Carvalho and Cliquet 2005 (Carvalho et al., 2005);



N = 12

Population: 12 male participants (C4 to C7), all complete with tetraplegia; Mean age  = 33.8 yrs; Median time post-injury = 77.58 mos

Treatment: BWSTT (30-50%) with neuromuscular electrical stimulation 20 min/day, 2 days/wk for 3 mos.

Outcome Measures: BP and HR.

·         After training, increases in mean systolic blood pressure (94 ± 5 mmHg to 100 ± 9 mmHg) at rest and during gait exercise.

·         There were no significant changes in post-exercise BP after training.

Ditor et al. 2005 (Ditor et al., 2005);



N = 8

Population: 8 participants (6 males, 2 females), AIS B-C, C4-C5, incomplete, mean age 27.6 yrs, mean 9.6 yrs post-injury.

Treatment: Progressive, BWSTT, 3 day/wk for 6 mos.

Outcome Measures: HR and BP variability, LF/HF ratio (indicative of sympathetic/parasympathetic tone).

·         Significant ↓ in resting HR (10.0%) after training.

·         No changes in resting systolic, diastolic, or mean arterial BP after training.

·         Significant reduction in the resting LF/HF ratio after training.

·         There were no significant effects of training on HR and/or BP variability during an orthostatic challenge (60° head up tilt).

Jack et al. 2009 (Jack et al., 2009);


Case Series

N = 2

Population: Participant A: female, T9 level injury, age 41 yrs, 2 yrs post-injury; Participant B: male, T6 level injury, age 40 yrs, 14.5 yrs post-injury

Treatment: BWSTT three 30-min sessions/wk for 16 wks (participant A) or 20 wks (participant B)

Outcome Measures: Measures of cardiopulmonary fitness: oxygen uptake (VO2); HRpeak; dynamic O2 cost

·         Both participants’ VO2 ↑ after exercise: participant A changed from 8.2 to 10.2 mL/kg/min; participant B changed from 13.8 to 18.2 mL/kg/min at week 17, after which the VO2 dropped back to 13.9 mL/kg/min.

·         HRpeak ↑ for both participants after training (89 to 119 bpm for participant A, 134 to 157 bpm for participant B). The dynamic O2 cost ↓ for both participants (115 to 29.03 mL/min−1/W−1 for participant A, 66.57 to 4.52 mL/min−1/W for participant B).


Seven BWSTT studies examined individuals with incomplete SCI, who engaged in active walking supported either above ground or above treadmills with individually-determined body weight support. In general, there were small increases in cardiorespiratory fitness and improvements in submaximal heart rate, indicating a small degree of cardiovascular changes after 4-13 weeks of BWSTT.

Two RCT studies were completed for high-level evidence. Alexeeva et al. (2011) used an RCT design to evaluate two forms of body-weight supported walking (i.e., fixed track vs. treadmill) vs conventional physical therapy and observed small, but clinically meaningful improvements in VO2peak. However, as these results were not statistically significant, some caution should be taken in their interpretation. Millar et al. (2009) conducted a 4-week RCT with a cross-over design, but did not observe any improvements in heart rate variability, a marker of autonomic nervous system function. They did indicate improvements in heart rate complexity, another marker of autonomic function. Changes in nervous system function were also noted by Ditor et al. (2005), who indicated improvements in heart rate variability after 6 months of BWSTT.

There is good evidence to indicate improved respiratory function after BWSTT in individuals with incomplete SCI. Both Terson de Paleville et al. (2013) (12-week BWSTT) and Soyupek et al. (2009) (6-week BWSTT) demonstrated improvements in forced vital capacity after training, which measures the total amount of air exhaled during a maximal breathing effort. Both studies were pre-post designs with small sample sizes, but provide corroborating findings for respiratory improvements after BWSTT.

Three studies examined individuals with motor complete SCI, using completely passive gait training in the upright position. Ditor et al. (2005) did not observe improvements in cardiorespiratory fitness, although there were small effects on markers of lower-limb vascular health. de Carvalho & Cliquet (2005) indicated increased blood pressure control after 3 months of BWSTT, while de Carvalho et al. (2006) indicated improved submaximal exercise capacity after 6 months of passive BWSTT, as noted by an increase in exercise oxygen consumption (VO2), ventilation and exercise blood pressure.

Five studies used robotic-assisted body-weight supported treadmill training (RABWSTT), with active initiation of gait. Gorman et al. (2019) used a RCT design to evaluate the efficacy of robotic (exoskeleton) therapy or aquatic therapy to increase cardiorespiratory fitness. Exoskeleton training was not able to increase VO2peak during conventional maximum arm ergometry testing but was able to increase mode-specific VO2 during exoskeleton walking sessions. Similarly, Gorman et al. (2016) demonstrated an increase in VO2 during RABWSTT-specific training. Hoekstra et al. (2013) used a 24-session pre-post design to evaluate fitness in individuals with incomplete SCI. No differences were observed in submaximal VO2 post-intervention, though improvements in submaximal heart rate and resting heart rate were observed. While Turiel et al. (2011) indicated improvements in diastolic heart function after 6 weeks of RABWSTT, they did not report translations into improved cardiorespiratory fitness. Finally, in the only positive study, Cheung et al. (2019) used an RCT design to indicate improvements in cardiorespiratory fitness after 8 weeks of RABWSTT; however, the magnitude of improvement was so small it would be considered negligible in a functional capacity.


There is Level 1b evidence (Millar et al. 2009) that at least 1 month of 3x/week BWSTT can improve autonomic nervous system function.

There is Level 4 evidence (Jack et al. 2009) that 16 weeks of 3x/week BWSTT can improve VO2peak.

There is Level 4 evidence (Stevens et al. 2015) that 8 weeks of 3x/week BWSTT can improve submaximal exercise capacity.

There is Level 4 evidence (Soyupek et al. 2009; Terson de Paleville et al. 2013) that 6 weeks of 5x/week BWSTT can improve respiratory function.

There is Level 4 evidence (de Carvalho & Cliquet 2005; de Carvalho et al. 2006; Ditor et al. 2005) that at least 3 months of passive BWSTT can improve aspects of cardiovascular function in individuals with motor-complete injuries.