Intensive Care Unit Acquired WeaknessNCT05279547
Locomotor Muscle Oxygenation and Activation During Acute Interval Compared to Constant-load Bed-cycling Exercise
A study testing Constant-load bed-cycling exercise and Interval bed-cycling exercise in people with Intensive Care Unit Acquired Weakness and Critical Illness, run by KU Leuven at 1 site in Belgium.
Trial summary
Up to 60% of patients admitted to the Intensive Care Unit (ICU) with a prolonged stay in the ICU develop complications such as intensive care unit acquired weakness (ICUAW) characterized by limb and respiratory muscle weakness. Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Intensive Care Unit Acquired Weakness, Critical Illness
- What is being tested?
- Constant-load bed-cycling exercise and Interval bed-cycling exercise
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 100 participants
- Where
- 1 siteBelgium
- Study dates
- 1 Feb 2023to Dec 2028
- Phase
- Interventional
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Full cooperatively adult patients indicated by the Adequacy Score of standardized 5 questions (SQ5) = 5/5
- Patients mechanically ventilated for longer than 48 hours during the same ICU admission
- Patients are expected to remain in the ICU for more than an additional 48 hours starting from study enrollment
- Patients able to perform active cycling for > 10 consecutive minutes
Who cannot join
- Pre-existing functional limitations
- Low limb injuries or conditions that would preclude in-bed cycling such as a body habitus unable to fit the bike
- Extreme obesity (body mass index >35 kg/m2)
- Neurologically unstable
- Acute surgery
- Palliative goals of care
Show all 27Show fewer
- Temperature > 40 °C
- An anticipated fatal outcome
- Evidence of coronary ischaemia, for example, chest pain or electrocardiogram changes
- Resting heart rate <40 or >120 beats per minute
- Mean arterial pressure <60 or >120 mmHg
- Peripheral capillary oxygen saturation < 90%
- Wounds, trauma or surgery of leg precluding cycle ergometry
- Wounds, trauma or surgery of pelvis precluding cycle ergometry
- Wounds, trauma or surgery of lumbar spine precluding cycle ergometry
- Coagulation disorder (international normalised ratio > 1.8, or platelets < 50,000 mcL)
- Intracranial pressure >20 mm Hg
- Femoral access other than femoral central line
- Acute deep vein thrombosis
- Pulmonary embolism
- >20 mcg/min of noradrenaline
- inotropic or vasopressor support comparable to a dose of noradrenaline >20mcg/min
- Fraction of inspired oxygen > 55%
- Arterial partial pressure of oxygen (PaO2) <65 torr (<8.66 kPa)
- Positive end-expiratory pressure > 10 cmH2O
- Respiratory rate > 30 breaths per minutes with adequate ventilatory support
- Minute ventilation >150 mL/kg body weight
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
Diego Poddighe contact
Belgium1 site, 1 recruiting
- Recruiting
University Hospital Leuven
Leuven, 3000
Daniel Langer, daniel.langer@kuleuven.be
Daniel Langer, PT, PhD
About this study
Official title: Locomotor Muscle Oxygenation and Activation During Acute Interval Compared to Constant-load Bed-cycling Exercise: A Pilot Study
Up to 60% of patients admitted to the Intensive Care Unit (ICU) with a prolonged stay in the ICU develop complications such as intensive care unit acquired weakness (ICUAW) characterized by limb and respiratory muscle weakness. ICUAW is associated with worse prognosis, longer ICU stay and increased morbidity and mortality.
Physical therapy (PT) interventions in the intensive care unit (ICU), can improve patients' outcomes.
Read more
However, improvements in muscle function achieved with standard physical activity interventions aiming at early mobilization are highly variable due to lack of consistency in definition of the interventions, lack of consideration for the complexity of exercise dose and/or insufficient stimulation of muscles during interventions. It has been suggested that modifying early mobilization and exercise protocols towards shorter intervals consisting of higher intensity exercises might result in more optimal stimulation of muscles.
In the present study the researchers therefore aim to simultaneously assess (by non-invasive technologies) locomotor muscle oxygenation and activation along with the measurements of the load imposed on respiration and circulation during two different training modalities i.e., moderate intensity continuous bed-cycling (endurance training) vs high-intensity alternated by lower intensity periods of bed-cycling (interval training).
Read the detailed description
Critical illness is related to high morbidity and mortality rates, and health-care costs. Up to 60% of patients admitted to the Intensive Care Unit (ICU) with a prolonged stay in the ICU develop complications such as intensive care unit acquired weakness (ICUAW) characterized by limb and respiratory muscle weakness. These abnormalities develop already within the first days to weeks after intensive care unit (ICU) admission and are related to immobility, sepsis, inflammatory response syndrome (SIRS), prolonged mechanical ventilation, multiple organ failure, and the use of corticosteroids. ICUAW is associated with worse prognosis, longer ICU stay and increased morbidity and mortality. Survivors of critical illness frequently report long-term physical impairments persisting up to 5 years after discharge.
Physical therapy (PT) interventions in the intensive care unit (ICU), can improve patients' outcomes. A systematic review of randomized controlled trials (RCTs) of strategies to improve physical functioning of ICU survivors identified the importance of PT interventions in the ICU. Early rehabilitation during ICU admission has the potential to result in important clinical benefits for patients. These findings highlight the importance of aiming to apply mobilization strategies early during ICU stay to maintain and improve physical functioning as good as possible.
With a projected increase in the number of critically ill patients, requiring rehabilitation in the ICU effective and efficient rehabilitation interventions are warranted. However, improvements in muscle function achieved with standard physical activity interventions aiming at early mobilization are highly variable. Therefore, there is a need for implementing more evidence-based PT interventions, as part of routine clinical practice. Variable results of current interventions may be due to lack of consistency in definition of the interventions, lack of consideration for the complexity of exercise dose and/or insufficient stimulation of muscles during interventions. It has been suggested that modifying early mobilization and exercise protocols towards shorter intervals consisting of higher intensity exercises might result in more optimal stimulation of muscles.
A recent study evaluating a cohort of 181 consecutive patients receiving 541 in-bed cycling sessions as part of routine PT interventions in ICU showed that constant-load bed-cycling appears to be both feasible and safe. In addition, recent evidence in patients with chronic lung disease shows that acute alteration of intense and less intense periods of exercise induced partial restoration of local muscle oxygen stores during the less intense periods of exercise facilitating the muscles to achieve higher exercise intensities during the intense periods, compared to constant-load submaximal exercise. Hence, in patients with chronic lung diseases, alternating intense with less intense loads during interval exercise may be physiologically more effective than constant submaximal workloads maintained during endurance type training for achieving a higher stimulation of locomotor muscles. This has not been investigated so far in intensive care unit patients.
- Being tested
- Constant-load bed-cycling exercise, Interval bed-cycling exercise
- Keywords
- ICU acquired muscle weakness, Quadriceps muscle, Near-infrared spectroscopy, Oxygenation, EMG, Early-mobilization, Bed-cycling, Interval exercise, Continuous exercise
- Medical subject headings
- Critical Illness
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Constant-load bed-cycling exerciseOther
Patients will actively cycle for a minimum duration of 10 minutes and a maximum duration of 20 minutes without breaks.
Interval bed-cycling exerciseOther
Patients will cycle for the same duration as during constant-load exercise. Interval bed-cycling session will consist of 30 seconds of high intensity exercise alternated by 30 seconds of passive cycling designed so that volume of training will be equal.
| Study group | Role | What they receive |
|---|---|---|
| Arm 1 (First constant-load then interval bed-cycling protocol) | Active comparator | During Day 1, patients will be familiarized with the constant-load and interval bed-cycling exercise against no resistance. Patients will be also randomized in the two arms of the study before the determination of the appropriate exercise intensities to be subsequently use during the constant-load and interval bed-cycling protocols on Day 2 and Day 3. Exercise intensities will be determined so that the volume of training during the two protocols will be equal.
During Day 2, patients randomized to arm 1 will perform the constant-load bed-cycling protocol. During Day 3, patients who executed the constant-load bed-cycling protocol on Day 1 (arm 1) will perform the interval bed-cycling protocol. Receives: Other: Constant-load bed-cycling exercise; Other: Interval bed-cycling exercise |
| Arm 2 (First interval then constant-load bed-cycling protocol) | Active comparator | During Day 1, patients will be familiarized with the constant-load and interval bed-cycling exercise against no resistance. Patients will be also randomized in the two arms of the study before the determination of the appropriate exercise intensities to be subsequently use during the constant-load and interval bed-cycling protocols on Day 2 and Day 3. Exercise intensities will be determined so that the volume of training during the two protocols will be equal.
During Day 2, patients randomized to arm 2 will perform the interval bed-cycling protocol. On Day 3 they will perform the constant-load bed-cycling protocol. Receives: Other: Constant-load bed-cycling exercise; Other: Interval bed-cycling exercise |
What is being measured
The primary outcome is the main question the study is designed to answer.
Differences between bed-cycling protocols in fractional oxygen saturation (StiO2,%) for each measured region of the m. quadriceps femoris
Assessed by near-infrared spectroscopy
Measured: constant-load and interval bed-cycling protocols administered in 2 different days within 1 week
Differences between bed-cycling protocols in activation (sEMG amplitude) for each measured region of the muscle quadriceps femoris
Assessed by surface electromyography
Measured: constant-load and interval bed-cycling protocols administered in 2 different days within 1 week
Adverse event rate during constant-load bed-cycling
Constant-load bed-cycling protocol will be considered as a safe intervention in case the adverse event rate will be less than 2.6%; adverse events: catheter/tube removal, increase in vasoactive medications >5mcg/min, increase in systolic blood pressure > 200 mmHg for > 2min, decrease in mean arterial pressure < 60 mmHg for > 2 min, decrease in heart rate < 50 bpm for > 2 min, increase in heart rate > 140 beats per minute for > 2 min, increase in respiratory rate and sustained > 5 min after session, decrease in peripheral capillary oxygen saturation < 88% for > 1 min requiring an increase in fraction of inspired oxygen > 0.1 sustained > 5 min)
Measured: 1 session of maximal 20 minutes of constant-load bed-cycling per patient
Adverse event rate during interval bed-cycling
Interval bed-cycling protocol will be considered as a safe intervention in case the adverse event rate will be less than 2.6%; adverse events: catheter/tube removal, increase in vasoactive medications >5mcg/min, increase in systolic blood pressure > 200 mmHg for > 2min, decrease in mean arterial pressure < 60 mmHg for > 2 min, decrease in heart rate < 50 bpm for > 2 min, increase in heart rate > 140 beats per minute for > 2 min, increase in respiratory rate and sustained > 5 min after session, decrease in peripheral capillary oxygen saturation < 88% for > 1 min requiring an increase in fraction of inspired oxygen > 0.1 sustained > 5 min)
Measured: 1 session of maximal 20 minutes of interval bed-cycling per patient
Percentage of completed constant-load bed-cycling sessions
The constant-load bed-cycling is deemed to be feasible if at least 80% of planned constant-load sessions were able to be commenced and 80% of commenced sessions can be completed
Measured: 1 session of maximal 20 minutes of constant-load bed-cycling per patient
Percentage of completed interval bed-cycling sessions
The interval bed-cycling is deemed to be feasible if at least 80% of planned interval sessions were able to be commenced and 80% of commenced sessions can be completed
Measured: 1 session of maximal 20 minutes of interval bed-cycling per patient
Secondary outcomes (10)
Differences in Relative dispersion (RD) of fractional oxygen saturation (StiO2,%) among the different regions of quadriceps femoris as indicator of heterogeneity of fractional oxygen extraction among different regions of quadriceps femoris muscle.
Differences between exercise protocols in Relative dispersion (RD) of fractional oxygen saturation (StiO2,%) among the different regions of quadriceps femoris (i.e., vastus lateralis, vastus medialis, rectus femoris upper part and rectus femoris lower part) as indicator of heterogeneity of fractional oxygen extraction among different regions of quadriceps femoris muscle.
Measured: 1 session constant-load bed-cycling + 1 interval bed-cycling session administered in 2 different days within 1 week.
Differences between exercise protocols in oxygenated hemoglobin/myoglobin (OxyHb/Mb), deoxygenated hemoglobin/myoglobin (DeoxyHb/Mb) and total hemoglobin/myoglobin concentration (TotHb/Mb) for each measured region of quadriceps femoris
Differences between exercise protocols in oxygenated hemoglobin/myoglobin (OxyHb/Mb), deoxygenated hemoglobin/myoglobin (DeoxyHb/Mb) and total hemoglobin/myoglobin concentration (TotHb/Mb) for each measured region of quadriceps femoris (i.e., vastus lateralis, vastus medialis, rectus femoris upper part and rectus femoris lower part)
Measured: 1 session constant-load bed-cycling + 1 interval bed-cycling session administered in 2 different days within 1 week.
Differences in Median frequency of sEMG of different regions of quadriceps femoris
Differences in Median frequency of sEMG of different regions of quadriceps femoris (i.e., vastus lateralis, vastus medialis, rectus femoris upper part and rectus femoris lower part) between exercise protocols
Measured: 1 session constant-load bed-cycling + 1 interval bed-cycling session administered in 2 different days within 1 week.
Differences in relative dispersion (RD) of sEMG values among the different regions of quadriceps femoris as indicator of heterogeneity of activation among different regions of quadriceps femoris muscle.
Differences between exercise protocols in relative dispersion (RD) of sEMG values among the different regions of quadriceps femoris as indicator of heterogeneity of activation among different regions of quadriceps femoris muscle.
Measured: 1 session constant-load bed-cycling + 1 interval bed-cycling session administered in 2 different days within 1 week.
Differences between bed-cycling protocols in heart rate
Assessed by monitoring vital signs
Measured: constant-load and interval bed-cycling protocols administered in 2 different days within 1 week
Differences between bed-cycling protocols in mean arterial blood pressure
Assessed by monitoring vital signs
Measured: constant-load and interval bed-cycling protocols administered in 2 different days within 1 week
Differences between bed-cycling protocols in respiratory frequency
Assessed by monitoring vital signs
Measured: constant-load and interval bed-cycling protocols administered in 2 different days within 1 week
Differences between bed-cycling protocols in minute ventilation
In case of mechanically ventilated patients
Measured: constant-load and interval bed-cycling protocols administered in 2 different days within 1 week
Differences between bed-cycling protocols in tidal volume
In case of mechanically ventilated patients
Measured: constant-load and interval bed-cycling protocols administered in 2 different days within 1 week
Differences between bed-cycling protocols in peripheral capillary oxygen saturation
Assessed by monitoring vital signs
Measured: constant-load and interval bed-cycling protocols administered in 2 different days within 1 week
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted15 Mar 2022
- Study start1 Feb 2023
- Primary completionDec 2028 (estimated)
- Study completionDec 2028 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (7)Papers the sponsor has linked to this study.
- Other trials for Intensive Care Unit Acquired WeaknessStudies of the same condition, open and under way.
- More trials run by KU LeuvenThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Crossover
- Model description
- two arms randomized cross-over trial
- Masking
- None (open label)
- Enrolment
- 100 participants (estimated)
Sponsor and investigators
- Lead sponsor
- KU Leuven
- Sponsor type
- University, hospital or other
- Collaborators
- Universitaire Ziekenhuizen KU Leuven
- Responsible party
- Principal investigator, Daniel Langer, KU Leuven
- Investigators
- Daniel Langer, Prof. Dr., Principal investigator, KU Leuven
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT05279547
- Sponsor's protocol ID
- S65934
- Status last verified
- Mar 2026
- First submitted
- 15 Feb 2022
- Last updated
- 18 Mar 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
Publications
Anekwe DE, Biswas S, Bussieres A, Spahija J. Early rehabilitation reduces the likelihood of developing intensive care unit-acquired weakness: a systematic review and meta-analysis. Physiotherapy. 2020 Jun;107:1-10. doi: 10.1016/j.physio.2019.12.004. Epub 2019 Dec 19.
PubMed 32135387Clarissa C, Salisbury L, Rodgers S, Kean S. Early mobilisation in mechanically ventilated patients: a systematic integrative review of definitions and activities. J Intensive Care. 2019 Jan 17;7:3. doi: 10.1186/s40560-018-0355-z. eCollection 2019.
PubMed 30680218Supinski GS, Valentine EN, Netzel PF, Schroder EA, Wang L, Callahan LA. Does Standard Physical Therapy Increase Quadriceps Strength in Chronically Ventilated Patients? A Pilot Study. Crit Care Med. 2020 Nov;48(11):1595-1603. doi: 10.1097/CCM.0000000000004544.
PubMed 32826429Grunow JJ, Goll M, Carbon NM, Liebl ME, Weber-Carstens S, Wollersheim T. Differential contractile response of critically ill patients to neuromuscular electrical stimulation. Crit Care. 2019 Sep 10;23(1):308. doi: 10.1186/s13054-019-2540-4.
PubMed 31506074Reid JC, Clarke F, Cook DJ, Molloy A, Rudkowski JC, Stratford P, Kho ME. Feasibility, Reliability, Responsiveness, and Validity of the Patient-Reported Functional Scale for the Intensive Care Unit: A Pilot Study. J Intensive Care Med. 2020 Dec;35(12):1396-1404. doi: 10.1177/0885066618824534. Epub 2019 Jan 22.
PubMed 30669936Hoffman M, Clerckx B, Janssen K, Segers J, Demeyere I, Frickx B, Merckx E, Hermans G, Van der Meulen I, Van Lancker T, Ceulemans N, Van Hollebeke M, Langer D, Gosselink R. Early mobilization in clinical practice: the reliability and feasibility of the 'Start To Move' Protocol. Physiother Theory Pract. 2022 Jul;38(7):908-918. doi: 10.1080/09593985.2020.1805833. Epub 2020 Aug 31.
PubMed 32866055Nickels MR, Aitken LM, Barnett AG, Walsham J, McPhail SM. Acceptability, safety, and feasibility of in-bed cycling with critically ill patients. Aust Crit Care. 2020 May;33(3):236-243. doi: 10.1016/j.aucc.2020.02.007. Epub 2020 Apr 18.
PubMed 32317212
Study at a glance
From the registry record, last updated by the sponsor on 18 Mar 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Locomotor Muscle Oxygenation and Activation During Acute Interval Compared to Constant-load Bed-cycling Exercise: A Pilot Study
- ClinicalTrials.gov ID
- NCT05279547
- Acronym / sponsor ID
- S65934
- Keywords
- ICU acquired muscle weakness, Quadriceps muscle, Near-infrared spectroscopy, Oxygenation, EMG, Early-mobilization, Bed-cycling, Interval exercise
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 100 participants (estimated)
- Lead sponsor
- KU LeuvenUniversity, hospital or other
- Collaborators
- Universitaire Ziekenhuizen KU Leuven
- Study start
- 1 Feb 2023 (actual)
- Primary completion
- Dec 2028 (estimated)
- Study completion
- Dec 2028 (estimated)
- First posted
- 15 Mar 2022 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
Up to 60% of patients admitted to the Intensive Care Unit (ICU) with a prolonged stay in the ICU develop complications such as intensive care unit acquired weakness (ICUAW) characterized by limb and respiratory muscle weakness. ICUAW is associated with worse prognosis, longer ICU stay and increased morbidity and mortality.
Physical therapy (PT) interventions in the intensive care unit (ICU), can improve patients' outcomes.
However, improvements in muscle function achieved with standard physical activity interventions aiming at early mobilization are highly variable due to lack of consistency in definition of the interventions, lack of consideration for the complexity of exercise dose and/or insufficient stimulation of muscles during interventions. It has been suggested that modifying early mobilization and exercise protocols towards shorter intervals consisting of higher intensity exercises might result in more optimal stimulation of muscles.
In the present study the researchers therefore aim to simultaneously assess (by non-invasive technologies) locomotor muscle oxygenation and activation along with the measurements of the load imposed on respiration and circulation during two different training modalities i.e., moderate intensity continuous bed-cycling (endurance training) vs high-intensity alternated by lower intensity periods of bed-cycling (interval training).
Detailed description
Critical illness is related to high morbidity and mortality rates, and health-care costs. Up to 60% of patients admitted to the Intensive Care Unit (ICU) with a prolonged stay in the ICU develop complications such as intensive care unit acquired weakness (ICUAW) characterized by limb and respiratory muscle weakness. These abnormalities develop already within the first days to weeks after intensive care unit (ICU) admission and are related to immobility, sepsis, inflammatory response syndrome (SIRS), prolonged mechanical ventilation, multiple organ failure, and the use of corticosteroids. ICUAW is associated with worse prognosis, longer ICU stay and increased morbidity and mortality. Survivors of critical illness frequently report long-term physical impairments persisting up to 5 years after discharge.
Physical therapy (PT) interventions in the intensive care unit (ICU), can improve patients' outcomes. A systematic review of randomized controlled trials (RCTs) of strategies to improve physical functioning of ICU survivors identified the importance of PT interventions in the ICU. Early rehabilitation during ICU admission has the potential to result in important clinical benefits for patients. These findings highlight the importance of aiming to apply mobilization strategies early during ICU stay to maintain and improve physical functioning as good as possible.
With a projected increase in the number of critically ill patients, requiring rehabilitation in the ICU effective and efficient rehabilitation interventions are warranted. However, improvements in muscle function achieved with standard physical activity interventions aiming at early mobilization are highly variable. Therefore, there is a need for implementing more evidence-based PT interventions, as part of routine clinical practice. Variable results of current interventions may be due to lack of consistency in definition of the interventions, lack of consideration for the complexity of exercise dose and/or insufficient stimulation of muscles during interventions. It has been suggested that modifying early mobilization and exercise protocols towards shorter intervals consisting of higher intensity exercises might result in more optimal stimulation of muscles.
A recent study evaluating a cohort of 181 consecutive patients receiving 541 in-bed cycling sessions as part of routine PT interventions in ICU showed that constant-load bed-cycling appears to be both feasible and safe. In addition, recent evidence in patients with chronic lung disease shows that acute alteration of intense and less intense periods of exercise induced partial restoration of local muscle oxygen stores during the less intense periods of exercise facilitating the muscles to achieve higher exercise intensities during the intense periods, compared to constant-load submaximal exercise. Hence, in patients with chronic lung diseases, alternating intense with less intense loads during interval exercise may be physiologically more effective than constant submaximal workloads maintained during endurance type training for achieving a higher stimulation of locomotor muscles. This has not been investigated so far in intensive care unit patients.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- None (open label)
- Number of arms
- 2
- Model description
- two arms randomized cross-over trial
| Arm | Type | Receives |
|---|---|---|
| Arm 1 (First constant-load then interval bed-cycling protocol) | Active comparator | Other: Constant-load bed-cycling exercise, Other: Interval bed-cycling exerciseDuring Day 1, patients will be familiarized with the constant-load and interval bed-cycling exercise against no resistance. Patients will be also randomized in the two arms of the study before the determination of the appropriate exercise intensities to be subsequently use during the constant-load and interval bed-cycling protocols on Day 2 and Day 3. Exercise intensities will be determined so that the volume of training during the two protocols will be equal. During Day 2, patients randomized to arm 1 will perform the constant-load bed-cycling protocol. During Day 3, patients who executed the constant-load bed-cycling protocol on Day 1 (arm 1) will perform the interval bed-cycling protocol. |
| Arm 2 (First interval then constant-load bed-cycling protocol) | Active comparator | Other: Constant-load bed-cycling exercise, Other: Interval bed-cycling exerciseDuring Day 1, patients will be familiarized with the constant-load and interval bed-cycling exercise against no resistance. Patients will be also randomized in the two arms of the study before the determination of the appropriate exercise intensities to be subsequently use during the constant-load and interval bed-cycling protocols on Day 2 and Day 3. Exercise intensities will be determined so that the volume of training during the two protocols will be equal. During Day 2, patients randomized to arm 2 will perform the interval bed-cycling protocol. On Day 3 they will perform the constant-load bed-cycling protocol. |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (4 listed)
- Full cooperatively adult patients indicated by the Adequacy Score of standardized 5 questions (SQ5) = 5/5
- Patients mechanically ventilated for longer than 48 hours during the same ICU admission
- Patients are expected to remain in the ICU for more than an additional 48 hours starting from study enrollment
- Patients able to perform active cycling for > 10 consecutive minutes
Key exclusion criteria (27 listed)
- Pre-existing functional limitations
- Low limb injuries or conditions that would preclude in-bed cycling such as a body habitus unable to fit the bike
- Extreme obesity (body mass index >35 kg/m2)
- Neurologically unstable
- Acute surgery
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Constant-load bed-cycling exercisePatients will actively cycle for a minimum duration of 10 minutes and a maximum duration of 20 minutes without breaks. | Other | Arm 1 (First constant-load then interval bed-cycling protocol), Arm 2 (First interval then constant-load bed-cycling protocol) |
| Interval bed-cycling exercisePatients will cycle for the same duration as during constant-load exercise. Interval bed-cycling session will consist of 30 seconds of high intensity exercise alternated by 30 seconds of passive cycling designed so that volume of training will be equal. | Other | Arm 1 (First constant-load then interval bed-cycling protocol), Arm 2 (First interval then constant-load bed-cycling protocol) |
Primary outcome
Differences between bed-cycling protocols in fractional oxygen saturation (StiO2,%) for each measured region of the m. quadriceps femoris
Time frame: constant-load and interval bed-cycling protocols administered in 2 different days within 1 week
Assessed by near-infrared spectroscopy
Differences between bed-cycling protocols in activation (sEMG amplitude) for each measured region of the muscle quadriceps femoris
Time frame: constant-load and interval bed-cycling protocols administered in 2 different days within 1 week
Assessed by surface electromyography
Adverse event rate during constant-load bed-cycling
Time frame: 1 session of maximal 20 minutes of constant-load bed-cycling per patient
Constant-load bed-cycling protocol will be considered as a safe intervention in case the adverse event rate will be less than 2.6%; adverse events: catheter/tube removal, increase in vasoactive medications >5mcg/min, increase in systolic blood pressure > 200 mmHg for > 2min, decrease in mean arterial pressure < 60 mmHg for > 2 min, decrease in heart rate < 50 bpm for > 2 min, increase in heart rate > 140 beats per minute for > 2 min, increase in respiratory rate and sustained > 5 min after session, decrease in peripheral capillary oxygen saturation < 88% for > 1 min requiring an increase in fraction of inspired oxygen > 0.1 sustained > 5 min)
Adverse event rate during interval bed-cycling
Time frame: 1 session of maximal 20 minutes of interval bed-cycling per patient
Interval bed-cycling protocol will be considered as a safe intervention in case the adverse event rate will be less than 2.6%; adverse events: catheter/tube removal, increase in vasoactive medications >5mcg/min, increase in systolic blood pressure > 200 mmHg for > 2min, decrease in mean arterial pressure < 60 mmHg for > 2 min, decrease in heart rate < 50 bpm for > 2 min, increase in heart rate > 140 beats per minute for > 2 min, increase in respiratory rate and sustained > 5 min after session, decrease in peripheral capillary oxygen saturation < 88% for > 1 min requiring an increase in fraction of inspired oxygen > 0.1 sustained > 5 min)
Percentage of completed constant-load bed-cycling sessions
Time frame: 1 session of maximal 20 minutes of constant-load bed-cycling per patient
The constant-load bed-cycling is deemed to be feasible if at least 80% of planned constant-load sessions were able to be commenced and 80% of commenced sessions can be completed
Percentage of completed interval bed-cycling sessions
Time frame: 1 session of maximal 20 minutes of interval bed-cycling per patient
The interval bed-cycling is deemed to be feasible if at least 80% of planned interval sessions were able to be commenced and 80% of commenced sessions can be completed
10 secondary outcomes
Differences in Relative dispersion (RD) of fractional oxygen saturation (StiO2,%) among the different regions of quadriceps femoris as indicator of heterogeneity of fractional oxygen extraction among different regions of quadriceps femoris muscle.
Time frame: 1 session constant-load bed-cycling + 1 interval bed-cycling session administered in 2 different days within 1 week.
Differences between exercise protocols in oxygenated hemoglobin/myoglobin (OxyHb/Mb), deoxygenated hemoglobin/myoglobin (DeoxyHb/Mb) and total hemoglobin/myoglobin concentration (TotHb/Mb) for each measured region of quadriceps femoris
Time frame: 1 session constant-load bed-cycling + 1 interval bed-cycling session administered in 2 different days within 1 week.
Differences in Median frequency of sEMG of different regions of quadriceps femoris
Time frame: 1 session constant-load bed-cycling + 1 interval bed-cycling session administered in 2 different days within 1 week.
Differences in relative dispersion (RD) of sEMG values among the different regions of quadriceps femoris as indicator of heterogeneity of activation among different regions of quadriceps femoris muscle.
Time frame: 1 session constant-load bed-cycling + 1 interval bed-cycling session administered in 2 different days within 1 week.
Differences between bed-cycling protocols in heart rate
Time frame: constant-load and interval bed-cycling protocols administered in 2 different days within 1 week
Differences between bed-cycling protocols in mean arterial blood pressure
Time frame: constant-load and interval bed-cycling protocols administered in 2 different days within 1 week
Differences between bed-cycling protocols in respiratory frequency
Time frame: constant-load and interval bed-cycling protocols administered in 2 different days within 1 week
Differences between bed-cycling protocols in minute ventilation
Time frame: constant-load and interval bed-cycling protocols administered in 2 different days within 1 week
Differences between bed-cycling protocols in tidal volume
Time frame: constant-load and interval bed-cycling protocols administered in 2 different days within 1 week
Differences between bed-cycling protocols in peripheral capillary oxygen saturation
Time frame: constant-load and interval bed-cycling protocols administered in 2 different days within 1 week
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 18 Mar 2026.
- Background: PubMed 32135387Anekwe DE, Biswas S, Bussieres A, Spahija J. Early rehabilitation reduces the likelihood of developing intensive care unit-acquired weakness: a systematic review and meta-analysis. Physiotherapy. 2020 Jun;107:1-10. doi: 10.1016/j.physio.2019.12.004. Epub 2019 Dec 19.
- Background: PubMed 30680218Clarissa C, Salisbury L, Rodgers S, Kean S. Early mobilisation in mechanically ventilated patients: a systematic integrative review of definitions and activities. J Intensive Care. 2019 Jan 17;7:3. doi: 10.1186/s40560-018-0355-z. eCollection 2019.
- Background: PubMed 32826429Supinski GS, Valentine EN, Netzel PF, Schroder EA, Wang L, Callahan LA. Does Standard Physical Therapy Increase Quadriceps Strength in Chronically Ventilated Patients? A Pilot Study. Crit Care Med. 2020 Nov;48(11):1595-1603. doi: 10.1097/CCM.0000000000004544.
- Background: PubMed 31506074Grunow JJ, Goll M, Carbon NM, Liebl ME, Weber-Carstens S, Wollersheim T. Differential contractile response of critically ill patients to neuromuscular electrical stimulation. Crit Care. 2019 Sep 10;23(1):308. doi: 10.1186/s13054-019-2540-4.
- Background: PubMed 30669936Reid JC, Clarke F, Cook DJ, Molloy A, Rudkowski JC, Stratford P, Kho ME. Feasibility, Reliability, Responsiveness, and Validity of the Patient-Reported Functional Scale for the Intensive Care Unit: A Pilot Study. J Intensive Care Med. 2020 Dec;35(12):1396-1404. doi: 10.1177/0885066618824534. Epub 2019 Jan 22.
- Background: PubMed 32866055Hoffman M, Clerckx B, Janssen K, Segers J, Demeyere I, Frickx B, Merckx E, Hermans G, Van der Meulen I, Van Lancker T, Ceulemans N, Van Hollebeke M, Langer D, Gosselink R. Early mobilization in clinical practice: the reliability and feasibility of the 'Start To Move' Protocol. Physiother Theory Pract. 2022 Jul;38(7):908-918. doi: 10.1080/09593985.2020.1805833. Epub 2020 Aug 31.
- Background: PubMed 32317212Nickels MR, Aitken LM, Barnett AG, Walsham J, McPhail SM. Acceptability, safety, and feasibility of in-bed cycling with critically ill patients. Aust Crit Care. 2020 May;33(3):236-243. doi: 10.1016/j.aucc.2020.02.007. Epub 2020 Apr 18.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
Diego Poddighe contact
Daniel Langer, Prof. Dr. principal investigator
KU Leuven
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Constant-load bed-cycling exercise and Interval bed-cycling exercise in people with Intensive Care Unit Acquired Weakness and Critical Illness, run by KU Leuven at 1 site in Belgium.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 4 inclusion and 27 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: looking for participants now, as of the sponsor's last update on 18 Mar 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Belgium. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Daniel Langer, Prof. Dr. (003216376497, daniel.langer@kuleuven.be), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Differences between bed-cycling protocols in fractional oxygen saturation (StiO2,%) for each measured region of the m. quadriceps femoris (time frame: constant-load and interval bed-cycling protocols administered in 2 different days within 1 week). The study lists 6 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT05279547, which also lists 7 linked publications.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 18 Mar 2026.