Can we use the 6-minute step test instead of the 6-minute walking test? An observational study

The six-minute step test can predict COPD exacerbations: a 36-month follow-up study

The six-minute step test (6MST) has been shown to be effective in assessing exercise capacity in individuals with COPD regardless of severity and, despite its easy execution, accessibility and validity, information on the prognostic power of this test remains uncertain. The aim of this study is to investigate whether the 6MST can predict the occurrence of exacerbations in patients with COPD. This is a prospective cohort study with a 36-month follow-up in patients with COPD. All patients completed a clinical assessment, followed by pulmonary function testing and a 6MST. The 6MST was performed on a 20 cm high step; heart rate, blood pressure, oxygen saturation, BORG dyspnea and fatigue were collected. Sixty-four patients were included in the study, the majority being elderly men. Performance on the 6MST demonstrated lower performance compared to normative values proposed in the literature, indicating a reduced functional capacity. Kaplan Meier analysis revealed that ≤ 59 steps climbed during the 6MST was a strong predictor of COPD exacerbation over a 36-month follow-up. We have identified a minimal threshold number of steps (≤ 59) obtained through the 6MST may be able predict the risk of exacerbations in patients with COPD.

Psychological changes in athletes infected with Omicron after return to training: fatigue, sleep, and mood

Background

This study aims to analyze the changes of approximately 1 month in fatigue, sleep, and mood in athletes after returning to training following infection with the COVID-19 Omicron strain and provide recommendations for returning to training after infection.

Methods

Two hundred and thirty professional athletes who had returned to training after being infected with COVID-19 in December 2022 were recruited to participate in three tests conducted from early January 2023. The second test was completed approximately 1 week after the first, and the third was completed about 2 weeks after the second. Each test consisted of completing scales and the exercise-induced fatigue measure. The scales included a visual analog scale, the Athens Insomnia Scale for non-clinical application, and the Depression-Anxiety-Stress scale. The exercise task was a six-minute stair climb test, and athletes evaluated subjective fatigue levels before and after exercise using another Visual Analog Scale and the Karolinska Sleepiness Scale.

Results

After returning to training, athletes' physical fatigue decreased initially but increased as training progressed. Cognitive fatigue did not change significantly. The exercise task led to elevated levels of physical fatigue after a longer duration of training. Sleep quality problems decreased rapidly after the start of training but remained stable with prolonged training. Depression levels continued to decline, while anxiety levels only reduced after a longer duration of training. Stress levels decreased rapidly after the start of training but did not change with prolonged training.

Conclusion

Athletes who return to training after recovering from COVID-19 experience positive effects on their fatigue, sleep, and mood. It is important to prioritize anxiety assessment and interventions during the short period after returning and to continue monitoring fatigue levels and implementing recovery interventions over a longer period of time.

Six-minute stepper test for evaluating functional exercise capacity in patients with sarcoidosis

BACKGROUND

Researchers and clinicians may benefit from alternative tests that do not require large physical spaces or corridors for simply evaluating functional exercise capacity in the clinical practice.

OBJECTIVE

Aim of this study was to investigate whether six-minute stepper test (6MST) is a valid tool for measuring functional exercise capacity in patients with sarcoidosis.

METHODS

Thirty-six patients with sarcoidosis and 18 healthy controls were evaluated with 6MST and six-minute walk test (6MWT). Patients performed 6MST twice. Cardiovascular and symptom responses to tests including heart rate, blood pressure, SpO₂, levels of dyspnea and fatigue were recorded.

RESULTS

Receiver operating characteristic (ROC) curve analysis revealed an area under the ROC curve of 0.74 for 6MST in identifying the patients and controls, indicating acceptable discriminative ability. Patients performed significantly worse in 6MST compared to controls (277±54 vs 349±87 steps; p<0.001). 6MST was able to explain 66% of variance in 6MWT (p<0.001), and there was a strong relationship between 6MWT and 6MST (r = 0.812). SpO₂ responses to tests were similar, however, 6MST generated more severe heart rate, dyspnea and fatigue responses. Intraclass correlation coefficient calculated for initial and retest scores of 6MST was 0.990, indicating excellent test-retest reliability. However, there was a systematical improvement (∼4%) in retest 6MST scores.

CONCLUSIONS

6MST is a valid and reliable alternative test for measuring functional exercise capacity in sarcoidosis. 6MST may also help better testing the upper limits of cardiac system and physical endurance as it is more physically demanding than 6MWT.

A Randomized Cross-Over Analysis of the 6-Minute Step Test When Administered in Different Music Listening Conditions to Healthy Young Adults

The 6-Minute Step Test (6-MST) is a simple, inexpensive field test that is increasingly used to evaluate cardiorespiratory fitness. Whether sufficient performance is revealed by this test and the effect on it of motivational factors such as music is unknown. In this cross-sectional, randomized, and crossover research design, we aimed to analyze 6-MST performance and test outcomes in different music-related auditory conditions of non-musical/non-rhythmic [NM/NR], musical/non-rhythmic [M/NR], and musical/rhythmic [M/R]). We had 38 healthy young adults (M age = 21.21, SD = 1.21 years; 60% male) complete all tests, and we measured their number of steps taken, heart rate, blood pressure, respiratory rate, peripheral oxygen saturation, perceived dyspnea, and fatigue on the modified Borg scale. We recorded individually calculated submaximal values according to heart rate reached after three tests. The number of steps increased in the M/R condition relative to other conditions (p = 0.003), and the amount of change in perceived leg fatigue was also higher in the M/R condition (p < 0.017). Despite variable test performances in different auditory conditions, we found no statistically significant difference in cardiovascular fitness and symptoms (p > 0.05). We concluded that the 6-MST is a useful tool for assessing maximum cardiac tolerance, especially if administered while listening to rhythmic music.

Reference equations of oxygen uptake for the step test in the obese population

The aim of this study was to establish reference equations for the six-minute step test (6MST) based on demographic, anthropometric, body composition, and performance variables able to predict oxygen uptake (V̇O₂) in obese individuals. Seventy-three obese adults (42±14 years old, body mass index >30 kg/m²) from both sexes were included. They underwent anamnesis, body composition evaluation, and the 6MST with expired gases registered simultaneously. Three equations were developed for the obese population (n=73; 59% female). The first equation was composed of the up-and-down step cycles (UDS), sex, and age as predictors; the second equation was composed of the UDS, age, and lean mass (LM). Both equations collectively explained 68.1% of the V̇O₂ variance in the 6MST, while the third equation, composed of the UDS, age, and body mass, accounted for 67.7% of the V̇O₂ variance. UDS, sex, age, LM, and body mass were important V̇O₂ predictors of 6MST in these obese individuals. This study contributes to the dissemination of a simple, inexpensive, and fast evaluation method that can provide important indicators of cardiorespiratory fitness and guide strategies for rehabilitation.

Responses of different functional tests in candidates for bariatric surgery and the association with body composition, metabolic and lipid profile

Individuals with obesity can have metabolic disorders and may develop impairments that affect the ability to exercise. The maximal incremental cardiopulmonary exercise test is widely used to assess functional capacity. However, submaximal tests such as the two-minute step test (2MST) and the six-minute walk test (6MWT) also allow this assessment. We propose to analyze whether body composition, metabolic and lipid profile influence the maximal and submaximal performance, and investigate these variables in response to different functional tests. Forty-four individuals with obesity, aged 18–50 years, underwent analysis of body composition, metabolic and lipid profile, incremental treadmill test (ITMT), 6MWT, and 2MST. One-way ANOVA, Pearson or Spearman correlation, and Stepwise multiple linear regression analysis were performed. ITMT induced a greater metabolic, ventilatory, cardiovascular, and perceived exertion demand when compared to the 6MWT and 2MST (p < 0.05). In addition, 2MST elicited a higher chronotropic (HR) and metabolic (V̇O₂) demand when compared to the 6MWT (p < 0.05). Significant correlations were found between tests and body composition, metabolic and lipid profile. Fat mass and low-density lipoprotein can explain 30% of the V̇O₂ variance in the ITMT; and fat mass, glucose, and performance in the 2MST can explain 42% of the variance of the distance walked in the ITMT. Obesity and its metabolic impairments are capable of influencing responses to exercise. ITMT generated greater demand due to the high stress imposed, however, 2MST demanded greater metabolic and chronotropic demand when compared to the 6MWT.

The 3 Minute Step Test is a validated field test to evaluate the functional exercise capacity in children aged 6 to 12

BACKGROUND

Field tests are useful to assess the functional exercise capacity. The 6minute walking test (6MWT) is the most common field test even if alternatives are needed. The main aim of the study was to verify if the 3minute step test (3MST) is a valid tool to measure the functional exercise capacity and can surrogate the 6MWT in healthy children from 6- to 12-years-old.

METHODS

This randomized cross-over trial recruited 30 healthy children from 6 to 12 years. One 6MWT and two 3MST (3MST₁ and 3MST₂) were performed randomly on 3 consecutive days. The variables were the distance (6MWT), the number of steps (3MST) and the cardiorespiratory parameters.

RESULTS

The distance walked during 6MWT was very strongly correlated to the number of steps during the 3MST (3MST₁: rho=0.833; P<0.001 and 3MST₂: rho=0.868; P<0.001). Heart rate (HR) was lower than the theoretical maximal HR at the end of both tests. The change in HR and perceived fatigue were significantly higher after the 3MST. A learning effect was observed in the 3MST (+8 steps; P<0.001).

CONCLUSIONS

The 3MST is validated and can be a surrogate for the 6MWT in healthy children population between 6 and 12 years old. A training test is required in these children.

The Six-Minute Step Test as a Predictor of Functional Capacity according to Peak VO2 in Cardiac Patients

BACKGROUND

Six-minute step test (6MST) is a simple way to evaluate functional capacity, although it has not been well studied in patients with coronary artery disease (CAD) or heart failure (HF).

OBJECTIVE

Analyze the association between the 6MST and peak oxygen uptake (VO2peak) and develop an equation for estimating VO2peak based on the 6MST, as well as to determine a cutoff point for the 6MST that predicts a VO2peak ≥20 mL.Kg-1.min-1.

METHODS

In 171 patients who underwent the 6MST and a cardiopulmonary exercise test, correlation, regression, and ROC analysis were used and a p < 0.05 was admitted as significant.

RESULTS

mean age was 60±14 years and 74% were male. Mean left ventricle ejection fraction was 57±16%, 74% had CAD and 28% had HF. Mean VO2peak was 19±6 mL.Kg-1.min-1 and mean 6MST performance was 87±45 steps. Association between 6MST and VO2peak was r 0.69 (p <0.001). The model VO2peak =19.6 + (0.075 x 6MST) - (0.10 x age) for men and VO2peak =19.6 + (0.075 x 6MST) - (0.10 x age) - 2 for women could predict VO2peak based on 6MST results (adjusted R 0.72; adjusted R2 0.53). The most accurate cutoff point for 6MST to predict a VO2peak ≥20 mL.Kg-1.min-1 was >105 steps (AUC 0.85; 95% CI 0.79 -0.90; p <0.001).

CONCLUSION

An equation for predicting VO2peak based on 6MST results was derived, and a significant association was found between 6MST and VO2peak. The cutoff point for 6MST, which predicts a VO2peak ≥20 mL.Kg-1.min-1, was >105 steps. (Arq Bras Cardiol. 2021; 116(5):889-895).

Reliability and Accuracy of 2-Minute Step Test in Active and Sedentary Lean Adults

OBJECTIVE

The purpose of this study was to evaluate the intrarater and interrater reliability of the 2-minute step test (2MST) in active and sedentary lean adults and to identify the test cutoff point to differentiate active from sedentary individuals.

METHODS

This observational study involved 4 mixed-sex groups (each with 50 lean participants): group 1, sedentary and aged 18 to 24 years; group 2, active and aged 18 to 24 years; group 3, sedentary and aged 25 to 44 years; and group 4, active and aged 25 to 44 years. The 2MST was administered independently by 2 examiners (with 3 months' training) at 2 different times, with a 7-day interval. Habitual physical activity was evaluated by means of the Baecke Questionnaire (BQ). In statistical analysis, the Pearson correlation coefficient was used to verify the correlation between the 2MST and BQ; intraclass correlation coefficients (ICC_2,3) were used to determine the intrarater and interrater reliability of the 2MST; and the receiver operating characteristic curve was used to identify the accuracy of the 2MST.

RESULTS

Excellent intrarater and interrater reliability were found for all 4 groups (intraclass correlation coefficients ≥ 0.83). Correlating the 2MST score with the BQ score, a significant, positive, weak correlation was observed (r = 0.344, P < .001). For differentiating active from sedentary individuals, the 2MST showed low accuracy (area under the curve = 0.671), with 61% sensitivity and 67% specificity.

CONCLUSION

This study showed that the 2MST is a reliable test with a low amount of inherent error. There was a significant correlation between the 2MST and usual physical activity measured, and slight accuracy in differentiating active from sedentary individuals.

Construct validity and reproducibility of the six-minute step test in subjects with obstructive sleep apnea treated with continuous positive airway pressure

OBJECTIVE

To evaluate the construct validity and reproducibility of the six-minute step test (6MST) in individuals with obstructive sleep apnea (OSA) treated with continuous positive airway pressure (CPAP).

METHODS

We evaluated 48 volunteers diagnosed with OSA and treated with CPAP for at least two months. The volunteers underwent the six-minute walk test (6MWT) and the 6MST, in random order and on different days, with an interval of, at most, seven days between the two tests.

RESULTS

A moderate positive correlation was found between the distance walked on the 6MWT and the number of steps climbed on the 6MST (r = 0.520; p < 0.001). There was no significant difference between the two 6MSTs in terms of the number of steps climbed (121.7 ± 27.1 vs. 123.6 ± 26.7). Reproducibility for performance on the 6MST and for cardiovascular variables was considered excellent (intraclass correlation coefficient > 0.8). Regarding cardiovascular responses, the 6MST produced higher values than did the 6MWT for HR at six minutes, percent predicted maximum HR, and leg fatigue at six minutes, as well as for systolic blood pressure at six minutes and at one minute of recovery.

CONCLUSIONS

The 6MST is valid and reproducible, producing greater cardiovascular stress than does the 6MWT. However, the 6MST is also characterized as a submaximal test for the assessment of exercise tolerance in individuals with OSA treated with CPAP.

Validity and reliability of the 6-min step test in individuals with coronary artery disease

OBJECTIVE

To assess the validity and reliability of the 6-min step test (6MST) in individuals with coronary artery disease (CAD).

METHODS

In a randomized and crossover design, 35 patients with CAD (65.8 ± 9.6 years), referred by a physician of a cardiology ambulatory, performed two 6MSTs and two 6-min walk tests (6MWTs) in order to assess reliability in patients with arterial coronary disease. The order of performance of the tests was established by a draw.

RESULTS

6MST test-retest reliability was excellent (intraclass correlation coefficient = 0.967; 95% CI: 0.766, 0.989; p < .05). There was an increase of 7.9 ± 8.2 steps from the first to the second 6MST, with a technical error of measurement = 8.0; p < .001. The correlations between distance walked in the 6MWT and number of steps in the 6MST in the first and second tests were 0.6 and 0.7 (p < .001), respectively.

CONCLUSION

The 6MST is a reliable test to measure functional capacity in individuals with CAD. The test is valid when using 6MWT as the gold standard. There is an 88% chance of a subject classified in a given tertile by the 6MWT being in the same tertile in the 6MST.

Validation of 6 min step test and 4-m gait speed in children: A randomized cross-over study

INTRODUCTION

Even if 6-min walking test (6MWT) is the criterion standard for functional exercise performance evaluation, new field tests are required as practical alternative. This study aims to establish the validity of the 6-min step test (6MST) and the 4-m gait speed (4MGS) in children.

METHOD

It is a randomized cross-over trial. Sixty one healthy children from 6 to 12 years were recruited. 6MWT, 6MST and 4MGS were randomly performed on three consecutive days. Pulsed oxygen saturation (SpO2), heart rate (HR), dyspnea (VAS) and fatigue (PCERT) were used as outcomes.

RESULTS

The distance walked during 6MWT was correlated to the number of steps during 6MST (r = 0.320; p = 0.013) and not correlated to 4MGS (r = -0.074; p = 0.575). No correlation between number of steps during 6MST and 4MGS (r = -0.129; p = 0.332) was found. HR was lower than the theoretical maximal HR after the tests. The increase in HR was significantly higher for 6MST and significantly lower for 4MGS than for 6MWT and it was higher for 6MST than for 4MGS. Dyspnea and perceived exertion were lower after 6MWT than after 6MST and higher than after 4MGS. They were also higher during 6MST than during 4MGS.

CONCLUSION

The three field tests are feasible in children. The 6MST and 4MGS are not valid surrogates to 6MWT in healthy children for functional exercise performance evaluation. Moreover, the cardio-respiratory response differs between the three tests.

Number of raised steps: A tool to assess brief and intense effort involving anaerobic metabolism

BACKGROUND

Although the initial anaerobic component of exercise adaptation is unavoidable, no specific functional test is available for use in routine non-sporting practice to evaluate it.

OBJECTIVE

To assess the bioenergetic and biomechanical properties of the Short and Fast Step Test (SFST), which consists of walking up and down a step as many times as possible in 1minute and to analyse its ability to explore the initial anaerobic component of effort in comparison to a reference self-paced step test.

METHODS

Overall, 31 healthy subjects (19 women; mean [SD] age, 32.4 [10.2] years) completed a test-retest of a self-paced step test and the SFST, with pre- and post-test measurement of blood lactate concentration and continuous recording of VO₂ and modelling of excess post-exercise oxygen consumption (EPOC), near-infrared spectroscopy (NIRS) of the quadriceps and mechanical power (estimated by the number of steps climbed and 3-D motion analysis).

RESULTS

Both step tests were well tolerated. The reliability of the bioenergetics parameters, number of raised steps, mechanical power and NIRS tissue saturation index was good. Indirect mechanical power (estimated from number of steps) was correlated with direct power (computed from the centre of mass). Lactate accumulation was significantly increased during exercise with only the SFST (mean [SD] increase, 3.86 [3.26]mmolL^-1 from resting values, P<0.05). EPOC was higher with the SFST than the self-paced step test (P<0.05). Only the SFST showed significant correlations between number of steps climbed and EPOC (r=0.84; P<0.001) and decreased tissue saturation index (NIRS) and EPOC area (r=-0.39; P<0.05).

CONCLUSIONS

SFST is feasible, well tolerated, reliable and responsive to explore a brief exercise involving anaerobic metabolism at submaximal intensity. The number of steps taken in 1minute seems a suitable parameter for practical application.