Exercise Progression Protocol for Lung Transplant GO: A Multicomponent Telerehab Exercise Intervention for Patients After Lung Transplantation

Background

Lung transplantation (LT) is an established treatment option for persons with end-stage respiratory failure. The number of LT procedures performed annually continues to rise as candidates for LT now includes more older-aged adults and patients with co-morbidities than in previous decades.^1–3 After transplant, lung function typically returns to near normal levels, yet other measures of success, such as improvements in physical functioning and exercise tolerance, lag behind, particularly among those who were deconditioned and inactive prior to transplantation.⁴ In fact, up to a year after transplant, lung transplant recipients (LTR) continue to experience a lower exercise capacity⁴, walk less, and spend less time doing moderately intense activities compared to age-matched healthy adults.⁵

Pulmonary rehabilitation programs are known to increase exercise tolerance for patients with chronic respiratory disease by increasing skeletal muscle mass, improving peripheral oxygen extraction, and reducing exercise-limiting symptoms, such as dyspnea and anxiety that often perpetuate the cycle of deconditioning.⁶ Exercise programs for LTR have also been shown to be effective in improving participation in daily activity⁷, exercise capacity, strength, and health-related quality of life.^8,9 Although recipients of lung transplant face fewer ventilatory exercise limitations, a referral to pulmonary rehabilitation program has become the standard of care to improve physical function, physical activity and establish a sustainable exercise routine.¹⁰ However, in spite of the potential benefits, pulmonary rehabilitation is underutilized. Up to half of patients referred never participate or fail to complete a pulmonary rehabilitation program.¹¹ This shortfall of participation for the general pulmonary patient has been attributed to factors such as issues with travel and transportation to a rehabilitation facility, lack of knowledge of pulmonary rehabilitation,¹² and patients’ perceptions of minimal benefit from pulmonary rehabilitaton.^13,14 In addition to these barriers, the lung transplant recipient may experience fear of infection mingling with others who attend group-based programs given their immunosuppressed state. Given the lack of participation in pulmonary rehabilitation coupled with frequent interruptions in rehabilitation that may occur as a result of medical complications, there is a need for the inclusion of self-management principles for the exercise program.¹⁵ A lack of self-management training is a barrier to adoption of exercise in LTRs as the ability to exercise at home with intermittent supervision is known to be critical for long-term adherence to a sustainable exercise routine.¹⁶

Telerehabilitation (TR) has been proposed as an alternative to traditional center-based rehabilitation programs.^17,18 Telerehabilitation is the delivery of rehabilitation services over telecommunication networks (videoconference, webcams) using the Internet. Telerehabilitation eliminates some of the barriers related to center-based programs as it allows patients to interact with healthcare providers remotely and can be used to assess patients and deliver therapy. In telerehabilitation, individuals do not have to travel to centers and concerns about infection in group settings are lessened as the LTR is able to participate from the home environment. Previous studies have evaluated TR-focused interventions in other populations, e.g., patients with knee osteoarthritis ¹⁹ and stroke,²⁰ and reported its benefits. In a recent description of a telerehabilitation program for lung transplant recipients during the COVID 19 pandemic, authors report broad usage of the telerehabilitation program and high levels of patient satisfaction.²¹ Thus, TR has the potential to offer a flexible, convenient, in-home exercise program to promote the self-management of exercise among LTR.²²

As in center-based pulmonary rehabilitation programs, telerehabilitation programs must be tailored and individualized given that patients present to rehabilitation with varying levels of functional ability and exercise tolerance. In addition, the programs must have a structured protocol for progression of exercises to allow the patient to safely achieve physical function and physical activity outcomes. Standardization of decision-rules about when to advance or modify an exercise protocol is particularly important when conducting clinical trials to determine intervention efficacy, identify the active ingredients of the intervention, and to examine dose effects that may explain variation in outcomes between subjects. Currently, there is a lack of published lung transplant-specific, exercise progression protocols that adequately describe how decisions are made and safety guidelines. In addition, a systematic review of physical exercise interventions for lung transplant recipients indicates that the existing studies do not adequately describe components of the exercise program to allow replication of the intervention.²³ Greater transparency with exercise protocols would assist rehabilitation providers in the development and evaluation of TR programs for LTRs, as well as other patient populations with complex rehabilitation needs, who are unable to participate in center-based programs.

The purpose of this report is to describe the exercise progression protocol for the LTGo multi-component TR exercise intervention for patients after lung transplantation. The LTGo intervention is a behavioral exercise intervention that provides individualized exercise training integrated with behavioral coaching for LTR in their home via a telehealth platform that includes 2-way video conferencing (Figure 1.) The LTGo intervention is delivered in two phases: Phase 1. Weekly home-based exercise training and behavioral coaching via a TR videoconferencing platform (includes approximately 10 sessions within 12 weeks); and Phase 2. Monthly behavioral coaching and exercise reinforcement sessions based on a behavioral contract followed by 3 telephone sessions (Table 1.)

Figure 1:

Exercise Session and Two-way Video Communication System

Table 1:

LTGo Intervention Phases

LTGO Intervention
Orientation and TR video system set-up (week 0)	1) Video Communication system set-up   2) Goal setting   3) Orientation to equipment   4) Safety procedure orientation   5) Orientation to exercise and prescription of week 0 exercises   6) Document orientation
Phase I (weeks 1-12) Telerehab Exercise training sessions	Video sessions weekly   1) Interactive exercise training   2) Behavioral coaching   3) Development of a contract for phase II (monthly goal and exercise plan)
Phase II (Weeks 13-24) Transition to Self-Management	Phone sessions monthly x 3   1) Assess progress and build upon or reset goals using a scripted format   2) Focus on increasing daily physical activity   3) Provision of written materials that address behavioral strategies for maintaining exercise Phone call format: On each call, the LTR is asked to develop an exercise goal and works with the interventionist to develop a SMART goal. Subsequent discussion includes strategies for self-monitoring identification of barriers/solutions. On call 3, the LTR is asked additional questions about program satisfaction and accomplishments in the program.

Intervention Development

The development of the LTGo TR intervention was overseen by an interprofessional team and guided by exercise principles from the National Emphysema Treatment Trial (NETT)²⁴ because rehabilitation needs are similar for LTR and patients with COPD (i.e., patients in both cases experience severe ventilatory impairments that limit physical activity and muscle conditioning.) The intervention was further refined based on findings from a pilot study of the feasibility, safety, usability, and acceptability of the LTGo TR exercise training sessions in LTRs.²⁵ For instance, in the pilot study, often weekly TR sessions had to be delayed or cancelled due to acute but treatable complications (e.g., infection, acute rejection), therefore, instead of 12 weekly sessions, the goal for Phase I was modified to complete at least 10 exercise sessions within 12 weeks. Also, post-study semi-structured interviews in the pilot study revealed the need for additional support for behavioral components to facilitate adherence to exercise. As a result, brief coaching sessions were integrated into the LTGo intervention to include behavior change strategies based on social cognitive theory, as well as a second phase that focuses on transition to self-management of the program.²⁶ We tailored the exercise protocol to maximize safety for participants with a wide range of abilities, and individualized our approach to exercise to maximize participant physical function and physical activity. Thus, a structured exercise progression protocol was developed to standardize the decisions for when and how to progress the exercise prescription for each individual over the course of the intervention to ensure reproducibility and fidelity.

Patients are deemed appropriate for the telerehabilitation intervention if they meet the following criteria: age ≥18 years; discharged to home after lung transplant surgery; greater than 4 weeks post-surgery to allow incision healing; and the physician reports that the patient has difficulty walking ¼ mile or climbing 10 steps without resting. Patients are deemed not appropriate for the telerehabilitation intervention if they have other chronic conditions that may severely limit participation in exercise training, i.e., cardiac, musculoskeletal or cognitive impairments, do not have home internet or smart device with Bluetooth capabilities, are participating in a formal exercise program during the active eligible study period with no plans to stop formal exercise, or have a medical issue that precludes participation.

Measures of Physical Function and Physical Activity:

Objective and self-reported measures of physical function and physical activity are assessed at baseline, 3 and 6 months. The method used to assess these outcomes depends on whether the assessment is performed in person or remotely (e.g., when face-to-face interactions with participants are limited.) The original in-person safety protocol was modified for remote assessment during the COVID-19 pandemic including additional instructions for the interventionist to dial 911 in case of an emergency and a national hotline and crisis line in the event of suicidal ideation. A full description of adaptations made to the physical function and physical activity assessments during remote administration during the COVID-19 pandemic is described elsewhere.²⁷

Physical Function Measures:

6-Minute Walk Test (6MWT) measures the distance walked over 6 minutes as a sub-maximal test of aerobic capacity/endurance. The 6MWT is a standardized, well-validated, objective measure of functional capacity.²⁸ Testing is conducted according to American Thoracic Society (ATS) Guidelines.²⁹ Briefly, the LTR is asked to walk in a designated space as far as long as possible for 6 minutes. Rest periods are allowed, but included in the time period. Longer distance on the 6MWT indicates better functional capacity. During remote testing when the 6MWT is not able to be performed in the patient’s home, the 30-second sit-to-stand test (30-s STS) is substituted as an alternate measure based on evidence from multiple studies that found moderate correlations with the 6WMT, including r= 0.528 to 0.660 (p < .001) in a sample of healthy young adults;³⁰ adults with chronic obstructive pulmonary disease;³¹ and pulmonary hypertension.³²

Berg Balance Scale (14 items) measure tests ability to handle tasks that require balance (e.g., sitting to standing, placing alternate foot on stool). Each item has a 5-point ordinal scale, from 0 (lowest level) to 4 (highest level). Total score ranges from 0 to 56 (higher score = better balance).³³ Validity in predicting fall risk was established among older adults and stroke survivors.^33,34 The Berg Balance Scale is performed during in-person and remote visits. When performed remotely, additional verbal instructions and demonstration of test items are included to optimize safety of testing. For example, to minimize fall risk the patient is asked to stand near, but not touching a wall during the assessment of free-standing activities in case of a loss of balance. Free-standing is permitted if the space does not accommodate standing close to a wall and the patient verbalizes comfort and safety with conducting the assessment.²⁷ To prevent possible fatigue during testing, the participate is offered frequent rest breaks throughout the assessment.

30-second Chair-Stand test measures lower body strength.³⁵ Validity with a lower body strength measure was tested in elders with COPD.³⁶ The test measures the number of times that the patient completes the sit to stand activity; more repetitions on this test indicate better lower body strength.

This test is performed on all LTR whether the testing is done in-person or remotely in the home. Prior to initiating the test, the participants ability to safely stand up from chair without help is assessed. If the participant is unable to stand independently, the test is stopped for safety purposes and the safety protocol is initiated by notifying the principal investigator for further risk assessment and instructions. The LTR is instructed to: 1) sit in the middle of a chair (17 inch height, with a straight back without armrests); 2) place hands on the opposite shoulder crossed at the wrists; 3) keep feet flat on the floor and back straight. On “Go,” LTR is asked to rise to a full standing position, sit down on the chair and repeat this move for 30 seconds. When the test is administered remotely, participants are asked to identify if the chair used is a standard height (approximately 17 inches) and if it has a straight back. If the person does not know the height of the chair, an estimation is used, and the assessor confirms that the participant’s feet are in contact with the floor. If the assessor notes that the chair does not meet criteria for the test (i.e., the chair has arm rests), the test is not conducted due to lack of equipment.

Physical Activity Measures:

The International Physical Activity Questionnaire Short Form (IPAQ-S)^37,38 is a subjective measure of health–related physical activity across four activity domains. The IPAQ-S is conducted by telephone. The physical activity data are expressed as a categorical score (low, moderate, or high) or a continuous score (MET-minutes per week). Median values and interquartile ranges for walking, moderate- intensity activities, vigorous-intensity activities, and a combined total physical activity score are determined.³⁸ Psychometric evaluations report good reliability and validity and demonstrate acceptable measurement properties for use in many settings and in different languages, including national population-based prevalence studies of participation in physical activity.³⁹

The Actigraph GT3X (ActiGraph, LLC., Pensacola, FL), an accelerometer monitor, is used to measure physical activity. The device provides tri-axial vector data in activity units, metabolic equivalent tasks (METs), or kilocalories. Validity has been established in people with COPD.⁴⁰ Physical activity is the average minutes spent per day in light (<3 METs) and moderate/vigorous (≥3 METs) activity at baseline, 3- and 6- months visits. The LTR is asked to wear the Actigraph on their waist for 7 days (starting the following day) during waking hours (≥10 hours of wear/day) except during imaging studies, bathing or showering.

Steps per day (SPD) is monitored using Fitbit data over 5 days as a correlate measure if 6MWT data are not available.⁴¹ The Fitbit data are used to calculate the average SPD over five days and steps are measured at baseline, 3 months, and 6 months. The Fitbit data are also collected weekly by the interventionist for use as an intervention tool, but not as an outcome measure for the LTGo intervention.

Main Components of the LTGo Multi-Component Telerehab Exercise Intervention

The LTGo multi-component TR exercise intervention is designed to assist LTR to learn and perform exercises to address deconditioning and decreased muscle strength. The program includes an exercise training program for progressive resistance training, flexibility, and balance exercises and is divided into two phases, Phase I training phase and Phase II transition to self-management phase. The LTGo intervention also incorporates behavioral coaching to help the LTR develop the skills to self-manage physical activity and maintain this behavior as a sustained habit using strategies that include incremental goal setting, self-monitoring, feedback and problem solving. All sessions are supervised by an interventionist and include exercise and a component of physical activity prescription.

The exercise protocol was developed by the study team which includes experts in physical therapy, nursing, pulmonary rehabilitation medicine, and exercise physiology. The study interventionist has a master’s degree in exercise physiology, clinical experience in cardiopulmonary rehabilitation, and has experience in clinical research, personal training and health coaching. The interventionist works under the guidance of a PhD-prepared physical therapist who is board certified as a clinical specialist in cardiovascular and pulmonary physical therapy and has experience in the treatment of lung transplant recipients in the acute care setting.

Initial Visit for Set-Up of the Program

At the initial visit, participants are issued a Fitbit to monitor daily steps. Participants in the LTGo intervention are also provided with the following exercise and monitoring equipment: adjustable cuff weights from 1-10 lbs., an exercise manual, an exercise diary, a pulse oximeter, and an automatic blood pressure monitor. The next visit is the first exercise visit for Phase 1 of the program which takes place remotely or in the home of the LTR, depending on the proximity to the research site and the safety of face-to-face interaction, e.g., due to the COVID-19 pandemic. For standardization, each LTR receives training in the same baseline exercises during the first exercise visit.

Exercise Safety Protocol

There are several measures in place to ensure patient safety during the TR exercise sessions. Before starting the exercise session, participants are asked to assess their resting vital signs including blood pressure (BP), heart rate and oxygen saturation (SpO₂) and record the measures in the exercise diary. Participants are instructed not to start exercise if their heart rate is > 85% of age predicted using the formula (220-age) x 0.85, the systolic BP (SBP) > 160 mmHg or diastolic BP (DBP) > 95 mmHg, the SpO₂ < 90%, or the rating of perceived exertions (RPE) > 6. If a vital sign parameter is not within these ranges, the participant is instructed to rest for 10 minutes and assess vital signs a second time. If after 10 minutes the vital signs are within the established parameters, the participant is able to begin the exercise protocol. If the values are still outside of the accepted parameters after 10 minutes or the participant is not feeling well, the participant is instructed not to start exercise and to contact their transplant coordinator or primary physician.

If participants are performing unsupervised exercise to supplemental the TR session, they are instructed to pause exercise and check vital signs if they experience leg cramps, shortness of breath, lightheadedness, pale or ashen appearance, or they are ‘not feeling right’ while performing the exercises. The LTR is instructed not to resume exercise for 10 minutes if their heart rate > 85% heart rate max, their SBP is > 160 mmHg or the DBP > 95 mmHg, oxygen saturation < 90%, or the RPE > 6. If the values do not return to acceptable parameters within 10 minutes, the LTR is instructed not to resume exercise and report immediately to their doctor or transplant coordinator. If the LTR vital signs have returned to acceptable values, they are able to continue the exercise session. The LTR is instructed to call 911 should chest pain, unusual shortness of breath, or changes in consciousness occur during exercise.

If a TR exercise session has to be terminated due to vital sign measures being outside of acceptable parameters, the interventionist stops the session and continues to assess the LTR. In the event of an emergency, the interventionist or LTR calls 911, provides the participant’s address, and notifies the study medical monitor.

Exercise Prescription and Progression

The LTR is instructed to perform the exercise prescription three times per week with two exercise sessions performed by the LTR independently in the home and the third supervised session delivered over the two-way video communication system with the interventionist. The technology used for the intervention is a HIPAA-sponsored Zoom account which provides additional privacy and security safeguards for the session. For example, all sessions require a password, participants cannot save the contents of the chat feature, and the participant cannot record the session. To date, there have been minimal issues with participant access to technology or technology failure. In the case of an issue with technology, the interventionist contacts the LTR using the Doximity app (Doximity, Inc. San Francisco, CA) to trouble-shoot the issue and provide guidance to the LTR. The Doximity application is a platform used by healthcare providers to securely contact patients using their cell phone while setting the caller ID to their hospital or office line.

Each TR exercise session is completed in 40 minutes, on average. The TR exercise sessions become lengthier as more exercises are added each week. During the supervised exercise session, the interventionist demonstrates each exercise and observes the LTR’s technique while performing the exercises. LTRs also provide their RPE) after each exercise set. The interventionist then utilizes the participant’s RPE, as well as observation skills, when it comes to exercise form, to modify the participant’s exercise prescription for the upcoming week. In addition, during phase I, a total of eight brief behavioral lessons are integrated into the sessions. The topics include how to set SMART goals, monitoring exercise, the Frequency, Intensity, Time, and Type (FITT) principles of exercise prescription, breathing techniques, time management, setbacks and barriers, social support and stress management. The LTR is also provided with a physical activity prescription based on steps per day and is asked to record each exercise session in an exercise diary.

If a TR session is cancelled by the LTR, the weekly phone contact is maintained and the interventionist attempts to reschedule the TR session, or sessions may be doubled-up in the same week as long as there is a buffer of at least 3 days in between sessions, until the end of phase 1, which lasts approximately 3 months. The Phase 1 coaching phase helps to prepare the LTR to enter Phase 2, which has a greater focus on self-management of the program.

Intervention fidelity monitoring is routinely conducted by trained members of the project staff and reviewed by the principal investigator. Prior to the start of the study, the principal investigator developed a list of items to determine whether intervention is being delivered as intended. Reviewers watch TR sessions and determine whether the interventionist completed each item on the list and fidelity is measured as a percent of the total number of items. All intervention sessions for 20% of participants randomized to intervention group are rated. Any drifts in fidelity ratings prompt re-training.

Strengthening Exercise Progression

The strengthening program is comprised of six lower extremity and four upper extremity exercises which are individualized to the LTR based on an assessment at the initial exercise visit (Table 2.) The weight for the initial training load is determined by assessing the amount the participant is able to lift and the participant’s RPE. The overall load for the upper extremities is limited to less than 10 pounds of weight until post-operative lifting restrictions are lifted after the first three months since the lung transplant surgery. The target RPE for the resistance exercise is an RPE equal to 4 (somewhat hard) on the Borg-RPE scale (1-10 scale).⁴² The participant is asked to perform each exercise in a controlled manner using the correct technique for eccentric and concentric contractions; cues/demonstrations are provided by the interventionist when needed. The exercises are modified if the participant is unable to perform the movement described. For example, if a participant is unable to lift his/her arm overhead to 180 degrees, the shoulder flexion exercise is modified for the participant to perform the exercise within the available range of motion. Exercises are progressed by increasing the number of sets and the amount of weight that is lifted.

Table 2:

Exercises in the LTGo program

Type of Exercise	Exercises	Exercise/Activity Progression Decision
Lower Extremity Strengthening	• Mini knee bends->Chair stands->Squats • Standing knee flexion • Seated knee extension • Standing back leg raises • Standing side leg raises • Standing heel raises	1. Add sets    2. Add weight    3. Eccentric training (5 second lowering)    4. Add pulses
Upper Extremity Strengthening	• Side arm raises • Front arm raises • Bicep curls • Triceps extension	1. Add sets    2. Add weight    3. Eccentric training (5 second lowering)    4. Add pulses
Balance Exercises	• Tandem stance • Standing on one foot	1. Add sets    2. Add time
Physical Activity Prescription	Primary mode: Walking	Increase step count based on prior week steps

During the initial exercise visit, the LTR is provided with a core set of four strengthening exercises including mini squats, standing knee flexion, shoulder abduction, and shoulder flexion. The target RPE for the resistance exercises is a 4 (somewhat hard) based on the RPE scale.⁴² At the first visit, the LTR is asked to perform the lower extremity exercise for 12 repetitions at an initial load of 2 lbs. using a cuff weight on the lower leg. The rating of perceived exertion is used to guide the load of the exercise with a target rating of 4. If the LTR performs an exercise with an RPE greater than 4, the amount of weight is lowered to 1 lb. If the LTR is able to perform the exercise with an RPE of 4, they are prescribed that exercise with a resistance of 2 pounds for that week. If they perform an exercise with a lower RPE (i.e. 2 or 3), the weight is increased to 3 pounds for that week. If they perform an exercise with an RPE of 0 or 1, the weight is increased to 4 pounds to elicit the target RPE of 4. The exercises performed with body weight are progressed using a structured model to increase difficulty. For example, lower extremity mini squats are progressed to chair stands and then a full squat based on the target RPE of 4. All exercises performed by the LTR are carefully observed by the interventionist so the interventionist can determine whether to increase the intensity of an exercise if they believe that the LTR failed to perform the exercise with proper form.

During subsequent weekly sessions, the LTR is asked to perform exercises in their exercise prescription and progressions to the exercise are made based on LTR perceived exertion with each exercise and executing the exercise with proper form. If the LTR is able to perform all exercises in their prescription within the weight, sets, repetitions and RPE limit and with proper form a new exercise is added to their prescription until all exercises in the program are included in their prescription (Table 3.) Additional exercises include seated knee extension, standing hip abduction, standing hip extension, heel raises, bicep curls, and triceps extension. Furthermore, if the LTR is able to perform an exercise for the upper end (12 reps) that elicits an RPE less than 4, a set is added to their prescription for that exercise. Then, if they perform an exercise for the upper end (2 sets of 12 reps) that elicits an RPE less than 4, resistance will be added one pound at a time until they reach the maximum resistance of 10 pounds. Once they are able to perform an exercise with a resistance of 10 pounds but their RPE is still less than 4, first eccentric training (5 second lowering) is prescribed then pulses or small quick movements of the extremity against gravity (10 pulses following their normal 12 repetitions). The prescription is progressed until the LTR can complete all resistance exercises, for 2 sets of 12 repetitions followed by 10 pulses, at the target RPE of 4. Figure 2 contains an excerpt from the progression model for a lower extremity resistance exercise with weights that would be utilized in a follow-up visit.

Table 3:

Weekly Exercise Progression Model

Timepoint	Resistance Exercises and Physical Activity Prescription	Repetitions and Progression
Home Visit	Mini-squats, standing knee flexion, arm flexion and abduction, tandem stance Physical Activity (Steps per day)	1 set x 12 reps with 2# lb and 1 set x 30 seconds for tandem stance Baseline step value established
Week 1	Home visit exercises Mini-squats ->Chair stands Seated knee extension Bicep curls One legged stance (added once tandem stance >30 sec achieved) Physical Activity (Steps per day)	1 set added to all exercises* 1 set x 12 reps 1 set x 12 reps x 2 lbs 1 set x 12 reps x 2 lbs 1 set x 10 seconds Baseline step value + 10% (Baseline steps)
Week 2	Week 1 exercises Chair stands -> Squats Standing hip extension Triceps extension Physical Activity (Steps per day)	1 Set or weight added to all exercises 1 set x 12 reps 1 set x 12 reps x 2 lbs 1 set x 12 reps x 2 lbs Week 1 step value + 10% (week 1 steps)
Week 3	Week 2 exercises Standing hip abduction Physical Activity (Steps per day)	1 Set or weight added 1 set x 12 reps x 2 lbs Week 2 step value + 10% (week 2 steps)
Week 4	Week 3 exercises Standing heel raises Physical Activity (Steps per day)	1 Set or weight added 1 set x 12 reps x 2 lbs Week 3 step value + 10% (week 3 steps)
Week 5	Week 4 exercises Physical Activity (Steps per day)	1 Set or weight added Week 4 step value + 10% (week 4 steps)
Week 6	Week 5 exercises Single leg heel raises Physical Activity (Steps per day)	1 Set or weight added 1 sets x 12 reps x 2 lbs Week 5 step value + 10% (week 5 steps)
Week 7	Week 6 exercises Physical Activity (Steps per day)	1 Set or weight added Week 6 step value + 10% (week 6 steps)
Week 8	Week 7 exercises Physical Activity (Steps per day)	1 Set or weight added+ Week 7 step value + 10% (week 7 steps)
Week 9	Week 8 exercises Physical Activity (Steps per day)	Weight added Week 8 step value + 10% (week 8 steps)
Week 10	Week 9 exercises Physical Activity (Steps per day)	Weight added Week 9 step value + 10% (week 9 steps)

^*Exercise progression to add sets and weights based on target RPE of 4 (somewhat hard) on RPE scale. Additional progressions are added for the LTR if weight limit of 10#, set limit of 2 sets, is reached including additional eccentric contraction time and pulses.

⁺Most participants are able to perform 2 sets of each exercise by week 8

Figure 2.

Sample of Progression Model for Leg Exercise for Follow-Up Visits

Balance Exercise Progression

There are two exercises in the balance exercise progression. At the first visit, the LTR is asked to perform tandem stance, for 30 seconds, with both the left foot and right foot as the lead foot. If the LTR is able to perform this exercise without losing their balance, they are asked to perform unilateral stance, for 10 seconds, on both the left foot and right foot. If the LTR is able to perform this exercise without losing their balance they are prescribed unilateral stance exercises that week. If they are unable to perform the exercise without losing their balance, they are prescribed tandem stance for 30 seconds for that week. During subsequent weekly sessions, the LTR is asked to perform one of the two balance exercises in their exercise prescription. Once the participant has progressed to standing on one foot for 10 seconds, the exercise is progressed by adding sets until the participant has reached the maximum of three sets. Once the participant has demonstrated they can perform standing on one foot for three sets of 10 seconds, they will be prescribed that exercise for three sets of 20 seconds. The prescription is progressed until the LTR can achieve three sets of 30 seconds on each foot.

Physical Activity Progression

The primary physical activity mode that is targeted in the LTGo intervention is walking at an intensity of 4 (somewhat hard) on the RPE scale. The LTR is issued a Fitbit Charge 3 (Fitbit, San Francisco CA, USA) at the baseline assessment and instructed in use for wear and tracking steps. During phase 1, the LTRs Fitbit data are uploaded to the study portal and reviewed by the interventionist on a weekly basis. After the first week in the study, the interventionist reviews the daily steps for the week and utilizes the highest step value as the daily step target for the following week. The daily step totals are reviewed by the interventionist each week thereafter. If the LTR reaches the step goal on a given day during the prior week, the goal for the next week is set at 10% above the highest step count in the prior week. If the LTR does not reach the goal set for a given week, any efforts the LTR made to engage in physical activity are encouraged and the step goal for the next week remains the same. The step count goal may be reduced in the case of a participant experiencing a medical setback with subsequent visit cancellations. In this case, the interventionist would utilize a tailored approach to develop a new realistic step goal in conjunction with the participant.

The individualized values for the target HR and RPE value and the stopping rules for HR and RPEs are written in each participant’s exercise booklet. In the case of a participant having their own exercise equipment (treadmill), they are encouraged to utilize the equipment to assist with reaching their physical activity goal. The interventionist assists the LTR in determining the exercise intensity on the treadmill by modifying the speed and/or grade for walking. Participants who utilize their own treadmill are instructed to exercise at an intensity the elicits an RPE of 4 on the Borg RPE Scale.

Documentation of Home Exercise

The LTR is expected to complete their exercise prescription an additional two times per week on their own to total three sessions per week (one supervised session via TR and two unsupervised sessions.) While performing the exercise on their own, the LTR should assess and document their vital signs (BP, HR, O2 saturation and RPE) prior to, and after, exercise. During the exercise session, they should document completed exercises as the intensity of each exercise including sets, repetitions, weight and RPE. In addition, they should also document any important information, such as signs and symptoms they are experiencing either before, during or after exercise. At the start of each TR visit, the LTR is asked to refer to their diary and let the interventionist know how the exercise sessions went, while completing it on their own. They are also asked if any exercises were too hard or too easy referencing the rating of perceived exertion scale, if any of the exercises caused pain or severe shortness of breath, and any other details that may assist the interventionist in making decisions about the progression or modification of the exercise prescription.

Discussion

The aim of this report was to describe the exercise progression protocol for an evidence-based, multi-component exercise intervention delivered remotely for LTR. An in-depth description of the progression protocol is important because there is the need for alternative exercise delivery models for pulmonary rehabilitation programs for LTRs. Traditional center-based rehabilitation programs are shown to be effective in improving exercise tolerance and health related quality of life in patients with respiratory disease.^43,44 Despite this, a large number of patients do not attend due to barriers such as disease exacerbations and illness, hospital admissions, transportation problems, risk of infection in group settings, and lack of availability of programs within the LTRs geographic region. TR is ideally suited to meet the needs of this unique population; however, established protocols for exercise progression have not been published which poses significant challenges for safety, reproducibility, and development of new programs.

A review of the literature revealed a lack of published exercise progression protocols for LTRs. This is problematic for clinicians who wish to replicate intervention research that has shown benefit to patients but also for researchers who want to implement and evaluate similar exercise interventions. In a systematic review that examined the replicability of physical exercise programs for LTRs in 2018, it was revealed that there were very few published studies that included the adequate description of Frequency, Intensity, Time, and Type (FITT) of the exercise intervention to allow replication. In addition, of the seven manuscripts included in the review, only 3 of the studies described resistance training provided to LTRs²³. This lack of detail limits the ability of clinicians and researchers to replicate the program so that patients may experience similar effects of training after LT. Our progression model, described herein, provides sufficient detail about the LTGo exercise progression so that others can replicate the intervention.

In addition to the aforementioned reasons, the description of the TR exercise progression protocol is timely as alternative delivery models for rehabilitation have been important in response to the COVID-19 pandemic. The pandemic has triggered the implementation of severe restrictions, such as social distancing, to better control the spread of the virus.⁴⁵ These restrictions have posed barriers for rehabilitation providers who typically work in close contact with patients and in group-based settings. As a result, there has been increased consideration of TR in physical therapist practice and the American Physical Therapy Association has expanded resources for providers who wish to implement TR within their practice.⁴⁶ Given that TR is a newer model for delivery of physical therapy interventions, our goal was to share specific details about the TR progression protocol, including the safety procedures and decision models, so that others who wish to replicate such programs are able both during the pandemic and beyond as traditional models of care-delivery evolve.

There are several limitations to this report. First, the described exercise progression model for LTGo is currently being evaluated in a randomized clinical trial and efficacy of the intervention has not been established. In addition, at the time of this report, study recruitment is ongoing, and we are not able to report data about study participants such as baseline levels of function and physical activity, which could assist clinicians with identification of populations best suited for this type of intervention. However, feedback from intervention participants about the acceptability of the progression model reveals that they find it satisfactory and easy to follow.

Conclusion

The LTGo program is an evidence-informed telerehabilitation program designed to improve physical function and physical activity in LTR. Physical therapists may be able to utilize the LTGo progression model protocol as a flexible alternative of remote delivery for LTRs as well as other groups of patients who are unable to attend in-person rehabilitation sessions.