Physical Activity Capacity Assessment of Patients With Chronic Disease and the 1-Minute Sit to Stand Test: Is There an Interest?

Objective This study aimed to evaluate the efficacy of the 1-minute Sit to Stand test (1MSTS) to determine physical activity capacities for patients with chronic disease. Methods For this cross-sectional study, we studied fifty patients with chronic disease and no beta-blocker treatment. They systematically performed a cardiopulmonary exercise test to determine maximal oxygen uptake (V'O2max). We considered two groups of patients based on the results of the functional evaluation of exercise performance: (1) No limitation in exercise performance (V'O2max greater or equal to 80% of the theoretical reference) and (2) limited exercise performance (V'O2max <80% of the theoretical value). All patients also received an 1MSTS on the same day. Results We found 22 (44.0%) patients with normal exercise capacity and 28 (56.0%) patients with limited exercise performance. In this sample, mean 1MSTS repetitions were 27.1 (7.1) and 25.2 (8.7), respectively. There were no significant differences between the two groups for repetition and Borg Scale end test. The correlation between V'O2max measured during the exercise test and 1MSTS repetitions displayed a positive slope [r = 0.401 (95% CI 0.114–625)]. Conclusion This study demonstrated a moderate relationship between 1MSTS and V'O2max for patients with chronic disease. 1MSTS did not permit the precise determination of physical activity capacities in this sample.

Objective: This study aimed to evaluate the efficacy of the 1-minute Sit to Stand test (1MSTS) to determine physical activity capacities for patients with chronic disease.
Methods: For this cross-sectional study, we studied fifty patients with chronic disease and no beta-blocker treatment. They systematically performed a cardiopulmonary exercise test to determine maximal oxygen uptake (V'O 2 max). We considered two groups of patients based on the results of the functional evaluation of exercise performance: (1) No limitation in exercise performance (V'O 2 max greater or equal to 80% of the theoretical reference) and (2) limited exercise performance (V'O 2 max <80% of the theoretical value). All patients also received an 1MSTS on the same day.
Results: We found 22 (44.0%) patients with normal exercise capacity and 28 (56.0%) patients with limited exercise performance. In this sample, mean 1MSTS repetitions were 27.1 (7.1) and 25.2 (8.7), respectively. There were no significant differences between the two groups for repetition and Borg Scale end test. The correlation between V'O 2 max measured during the exercise test and 1MSTS repetitions displayed a positive slope [r = 0.401 (95% CI 0.114-625)].
Conclusion: This study demonstrated a moderate relationship between 1MSTS and V'O 2 max for patients with chronic disease. 1MSTS did not permit the precise determination of physical activity capacities in this sample.  (Csuka and McCarty, 1985). The 1-minute Sit to Stand (1MSTS) test version described by Koufaki et al. in 2002 was developed to assess a patient's aerobic capacity within a short time and in a limited space (Painter et al., 2000;Koufaki et al., 2002;Bohannon and Crouch, 2019;Simonelli et al., 2021). Indeed 1MSTS only requires a chair, stopwatch, and <2 m² of floor space. Our main goal was to evaluate the level of the relationship between the aerobic exercise performance capacity and 1MSTS results in a sample of patients suffering from chronic disease following a hospital based adapted physical activity program.

METHODS
This is a cross-sectional monocentric study performed at the Nancy University Center of Sports Medicine and APA, France, between February 2020 and July 2021, in patients requiring implementation of APA. APA is a means that allows the movement of people who, due to their physical, mental, or social status, cannot perform physical activity under normal conditions. The inclusion criteria were age >18 years old, with the ability to perform a cardiopulmonary exercise test and participate in supervised APA practice using a telemetry wireless system to monitor and record HR during the first session. The exclusion criteria were beta-blocker treatment and joint pain or limitations.

Demographic, Clinical Data, and Intervention
Data collected from the included patients were age, gender and body mass index (BMI). We classified the patient's referral department categories behind the APA program into four groups: Obesity, Rheumatology and Others. A maximum cardiopulmonary exercise test was carried out on all included patients.
Following the cardiopulmonary exercise test, the sample was split into two groups (Shvartz and Reibold, 1990; American Thoracic Society American College of Chest Physicians, 2003; Pedersen and Saltin, 2015;Carré, 2016): (1) No limitation of exercise performance capacities: those with normal maximal oxygen uptake [(V'O 2 max) ≥80% of the reference value] and (2) limitation of exercise performance capacities defined by a Abbreviations: 1MSTS, 1-minute Sit to Stand test; 6MWT, Six-Minute Walk test; APA, adapted physical activity; BMI, body mass index; HR, heart rate; HRpeak, peak heart rate; IQR, interquartile range; RER, respiratory exchange ratio; SD, standard deviation; V'O 2 max, maximal oxygen uptake. reduced V'O 2 max (<80% of the reference value). We used Wasserman equation for reference values (Roca et al., 1997;Radtke et al., 2019). The actual peak HR (HRpeak) was measured during the exercise test.
• Exercise test procedure: V'O 2 max was established during an incremental exhaustive exercise test on a cycle ergometer (eBike, GE Healthcare, France). For each patient, a progressively increasing work rate protocol was designed (rest, followed by an incremental phase of exercise every minute) so that volitional exhaustion is reached following 8-12 min of exercise. Respiratory and metabolic variables (minute-ventilation, tidal volume, frequency of breathing, V'O 2 , V'CO 2 ) were measured breath-by-breath through a mask connected to a pneumotachograph and O 2 and CO 2 analyzers (Vyntus TM CPX, Vyaire, Germany The 1MSTS was measured before the exercise test on the same day according to international recommendations (Koufaki et al., 2002;Vaidya et al., 2016). The test was performed using a chair of standard height of 45 cm without arm rests over 1 min. The patient had to be seated upright on the chair positioned against a wall. The patient sat with the knees and hips flexed to 90 • , feet placed flat on the floor, hip-width apart, and the hands placed on the hips. Every rise from the chair was validated to check if a complete sit-to-stand-to-sit sequence was achieved. The Modified Borg Scale was used to assess fatigue and the number of repetitions was measured. HR before and after 1MSTS was measured.

Statistical Analysis
Both descriptive and comparative analyses were made by accounting for the nature and distribution of the variables. Qualitative variables were described as frequencies and percentages; quantitative variables were evaluated using the mean ± standard deviation (SD) or with the median and interquartile range (IQR  (Schober et al., 2018). The significance level was set at 0.05 for the entire study. IBM TM SPSS Statistics v23 was used for the data analysis.

Ethics and Dissemination
All data used were obtained from the medical records. No supplementary examination was necessary for patients to meet the inclusion criteria. This study is registered with the Information Technology and Freedoms Commission for the University Hospital of Nancy (file number: 2021PI191) and on Clinicaltrials.gov (NCT05146544) and was designed in accordance with the general ethical principles outlined in the Declaration of Helsinki. The protocol of this study was approved by the Information Technology and Freedoms Commission. All patients gave their consent for the use of their medical data during the period they received medical care at the University Hospital. The Ethics Committee waived the requirement of written informed consent for participation.

Demographic, Clinical Data, and Intervention
Fifty patients were included in the study, 41 (82%) of whom were women. Mean age was 44.1 (±10.9) years with a mean BMI of 36.5 (±9.1) kg/m 2 . We found 28 (56.0%) patients with limited exercise capacities and 22 (44.0%) patients with normal exercise performance. There were no significant differences between the two groups for demographic and clinical characteristics, except for gender (p = 0.028) ( Table 1). But multivariate analysis corrected this, only age was significant with p = 0.021 (p = 0.056 for gender).

Relationship Between Physical Activity Capacities and Results of 1MSTS
In this sample, for normal and limited exercise patients, the 1MSTS mean repetitions were 27.1 (7.1) and 25.2 (8.7), respectively, with no significant difference (p = 0.386). There were no significant differences between the two groups for HR and Borg Scale after the test (p = 0.339 and p = 0.793, respectively). The correlation between V'O 2 max measured during the exercise test and 1MSTS repetition by exercise performance level showed a positive slope [r = 0.401 (95% CI 0.114-625)] (Figure 1).

DISCUSSION
The study described a moderate correlation between 1MSTS and V'O 2 max in patients suffering from chronic disease following APA. Indeed, it was not possible to ascertain exercise aerobic performance capacity with the 1MSTS. The 1MSTS test was developed in 2002 to assess the aerobic exercise capacities of patients with chronic disease (Koufaki et al., 2002) and was found to be a good alternative to the Six-Minute Walk Test (6MWT) which, unlike the 1MSTS which only needs a small space, requires a corridor at least 30 m long for effective evaluation (Ozalevli et al., 2007;Puhan et al., 2013). Our study revealed a moderate correlation between V'O 2 max and 1MSTS in patients with normal exercise capacities, but the result was better for patients with lower exercise capabilities (Figure 1). Our study contrasts with the previous study made by Nakamura et al. that showed a very strong correlation between V'O 2 max and 1MSTS repetition intervals (r = 0.94) unlike our result which based on absolute repetition number (Nakamura et al., 2014). Indeed, Nakamura study was carried out on a population of 10 young people without obesity [age mean: 22.3 (2.2) years and BMI mean 22.5 (4.1) kg/m²]. To date, no study has been carried out in such equivalent population. However, similar analyses carried out using the 6MWT show a positive correlation of a similar order of magnitude (0.42-0.58) (Guyatt et al., 1985;Cahalin et al., 1996). In the case of elite athletes, the V'O 2 max alone cannot explain performance. In this case a moderate correlation between the V'O 2 max and the time to exhaustion (r = −0.63). Indeed, the influence of methods and mental state influence performance. On the other hand, in our population, VO 2 max is a faithful reflection of exercise capacities.
The first publication referring to the Sit to Stand test aimed only at assessing the capacity of the lower limb extensor muscles (Csuka and McCarty, 1985). In fact, the initial test consisted of recording the time taken to stand ten times from a standard chair. In 2002, Koufaki et al. standardized the duration of this test to 1 min, to count the number of repetitions required to define the muscular aerobic capacities of patients with respiratory or chronic disease (Koufaki et al., 2002;Ozalevli et al., 2007;Puhan et al., 2013;Bohannon and Crouch, 2019). However, the 1MSTS test has limitations in young patients or in those with scarcely any functional restraints as it reflects the strength of the lower muscles and not of overall aerobic capacity (Ritchie et al., 2005;Rausch-Osthoff et al., 2014;Zanini et al., 2015;Vaidya et al., 2016;Bohannon and Crouch, 2019). Indeed, a strong correlation is observed (r = 0.8) in healthy subjects aged 55-70, with no chronic disease, while the association is weaker in patients presenting a Chronic Obstructive Pulmonary Disease (r = 0.50). It is probably the reason for the moderate correlation observed in our sample of patients with capacity limitations.
This study has limitations. Firstly, the size sample of only 50 patients from a single hospital center, prevents any extension of the results. In addition, the inclusion of many obese participants limited a subgroup exploration of different chronic pathologies.
The main strength of this study is the focus of V'O 2 max as a gold standard to assess the functional capacities of patients. It also incorporates all the recommendations of the French Health Act issued by the Ministry of Social Affairs and Health.
In conclusion, our study explored the moderate relationship between 1MSTS results and V'O 2 max as well as the possible inability of this test to detect the physiological exercise aerobic capacity of patients with chronic disease. However, this test may be of interest for characterizing an evolution in the general capacities of the patient practicing an adapted physical activity. An analysis of a larger and heterogeneous population and longitudinal clinical trial design would be necessary to make this observation more explicit, and hence pave the way for the implementation of new exercise assessment programs for patients with chronic disease requiring APA.

DATA AVAILABILITY STATEMENT
The raw data supporting the conclusions of this article will be made available by the authors, without undue reservation.