Optimizing Recovery in Pediatric ALL Survivors: A Training Comparison

Seventy-two pediatric ALL survivors were recruited from the Pediatric Oncology and Hematology departments of three referral hospitals in the Riyadh region, Saudi Arabia. Inclusion criteria required participants to be aged 10-18 years, have completed chemotherapy, present with secondary sarcopenia, and possess normal cardiac structure and function without lower limb deformities. Participants were also required to be non-regular exercisers. Exclusion criteria included a history of secondary cancers, neurodegenerative impairments affecting memory, attention, or executive function, or any neuromusculoskeletal condition likely to impede training compliance (e.g., recurrent intensive cramps or impaired proprioceptive function).

Outcome Measures

Cardiopulmonary Fitness: Peak oxygen uptake (VO₂ peak) was assessed using the McMaster cycle ergometer protocol.

Functional Capacity: This was evaluated via three performance-based tests: the 6-Minute Walk Test (6MWT), the Timed Up and Down Stairs Test (TUDS), and the 4x10 Meter Shuttle Run Test.

Interventions

All interventions were delivered three times per week for 12 consecutive weeks under close supervision by an experienced pediatric physical therapist.

Constant-Load Aerobic Exercise (CL-AEx) Group: This group (n=24) performed a structured exercise regimen plus a moderate-intensity aerobic training program. The aerobic component was maintained at a constant intensity of 65% of the maximum age-predicted heart rate for 45 minutes per session, each preceded by a 5-minute warm-up and followed by a 5-minute cool-down.

Graded Aerobic Exercise (G-AEx) Group: This group (n=24) performed the same structured exercise regimen plus an aerobic program with progressive intensity and duration. Starting at 50% of maximum age-predicted heart rate for 25 minutes, the parameters were increased every two weeks, culminating at 75% for 50 minutes in the final two weeks. Each session also included a 5-minute warm-up and cool-down.

Control Group: This group (n=24) performed only the structured exercise regimen for 45 minutes per session. The regimen included flexibility exercises, progressive resistance training, balance training, and conditioning activities.

• Constant-load Aerobic Exercise (Other): The CL-AEx group completed a 12-week, moderate-intensity aerobic training program in addition to the structured exercise regimen. The aerobic component was performed three times per week at a fixed intensity of 65% of the maximum age-predicted heart rate for 45 minutes per session. Each session included a 5-minute warm-up and a 5-minute cool-down. The intensity and duration remained constant throughout the intervention period.
• Graded Aerobic exercise (Other): The G-AEx group completed a 12-week aerobic training program that progressively increased in intensity and duration, in addition to the structured exercise regimen. Sessions were conducted three times per week. The program commenced at an intensity of 50% of the maximum age-predicted heart rate for 25 minutes. Parameters were increased every two weeks, culminating in an intensity of 75% for 50 minutes during the final two weeks. Each session included a standard 5-minute warm-up and 5-minute cool-down.
• Structured Exercise regemin (Other): The structured exercise regimen was conducted three times per week for 45 minutes per session over 12 consecutive weeks. Each session consisted of flexibility exercises, progressive resistance training, balance training, and low-intensity conditioning activities.

Primary outcomes

• Peak oxygen uptake [2 months]: The peak oxygen uptake (mL/kg/min) was assessed through a symptom-free exercise tolerance test (i.e., the McMaster cycling protocol).

Secondary outcomes

• Six-minute walk test [2 months]: This test identified the maximum distance (m) that each patient was able to cover over six minutes on a straight flat 30-m walkway, without running or jogging. Walking is regarded as more efficient in line with a longer distance coverage.
• 4x10 meter Shuttle Run test [2 months]: This test identified the maximum distance (m) that each patient was able to cover over six minutes on a straight flat 30-m walkway, without running or jogging. Walking is regarded as more efficient in line with a longer distance coverage.
• Timed up and down stairs test [2 months]: This test measured the time (seconds) that each patient took to climb up and down a 14-step stair flight (each 20 cm in height). Better performance is indicated by a shorter time.

Sex: All, ages: 10 Years to 18 Years

Inclusion Criteria:

* Age between 10 and 18 years old
* Complete maintenance chemotherapy
* Normal cardiac structure and function
* Absence of lower limb deformities
* Not engaging in regular exercise regimens

Exclusion Criteria:

* Secondary cancers
* Neurodegenerative impairments affecting memory, attention, or executive functioning
* Neuro-musculoskeletal conditions are likely to impede the training.

• Ragab K Elnaggar, PhD, Principal investigator, Prince Sattam Bin Abdulaziz University