A pilot study of six kids with leukemia or lymphoma found that exercise programs during early cancer treatment are not yet feasible as currently designed, with only 51% of participants sticking with the program. However, Gram Research analysis of the data showed that kids do experience significant fitness loss during early treatment, with heart fitness dropping 3.8 standard deviations below normal and hand grip strength dropping 1.5 standard deviations. Researchers concluded that future exercise programs need major redesigns to work with kids’ medical needs and treatment schedules before they can be tested in larger studies.
When kids and teens with leukemia or lymphoma start cancer treatment, they often receive high-dose steroids that can weaken their muscles and hurt their fitness. Researchers wanted to see if exercise during the first eight weeks of treatment could help. In this small pilot study of six young patients, they tested whether an exercise program was even possible to do during intense cancer therapy. While the study was too small to prove exercise works, it showed that kids undergoing early cancer treatment do lose muscle strength and fitness, and future studies should design programs that work better with their medical needs.
Key Statistics
A 2026 pilot randomized controlled trial of six adolescents with leukemia or lymphoma found that only 51% adhered to an exercise program during the first eight weeks of cancer treatment, falling short of the 80% feasibility target.
According to research reviewed by Gram, kids undergoing early cancer induction therapy experienced cardiorespiratory fitness drops of 3.8 standard deviations below normal, with hand grip strength declining 1.5 standard deviations in the same eight-week period.
A feasibility pilot study published in Frontiers in Pediatrics (2026) showed that only 67% of families consented to participate in an exercise intervention during early leukemia or lymphoma treatment, below the prespecified 80% recruitment target.
The Quick Take
- What they studied: Whether kids and teens with blood cancers could safely do exercise during their first eight weeks of cancer treatment, and whether exercise might help prevent the muscle weakness and fitness loss caused by steroid medications.
- Who participated: Six young people aged 10 to 17 years old who had just been diagnosed with leukemia or lymphoma. Two were assigned to do exercise, and four were in a control group that didn’t exercise.
- Key finding: The study didn’t work as planned: only 67% of families agreed to join, only 51% stuck with the exercise program, and only 70% completed all the fitness tests. However, the data showed that kids did lose significant muscle strength and heart fitness during early cancer treatment, with hand grip strength dropping by about 1.5 standard deviations and peak heart fitness dropping by 3.8 standard deviations.
- What it means for you: This pilot study shows that exercise programs for kids with cancer during early treatment need major redesigns to actually work. The good news is that researchers now understand the challenges better and can create more realistic programs in the future that fit with kids’ medical needs and treatment schedules.
The Research Details
This was a pilot randomized controlled trial, which means researchers randomly assigned kids to either an exercise group or a control group that didn’t exercise. A pilot study is a small test run designed to see if a bigger study is even possible. The researchers followed six young people with leukemia or lymphoma for eight weeks starting from when they began cancer treatment. Half got an exercise program plus one nutrition counseling session, while the other half got the nutrition counseling only. The researchers measured things like hand grip strength, how far kids could pedal on an exercise bike, how many times they could stand up from a chair, and their muscle size using ultrasound.
The study was designed to check if the exercise program was actually doable: Could families agree to join? Would kids stick with the exercise? Could researchers collect all the measurements? Would kids stay safe? These “feasibility” questions are just as important as whether exercise actually works, because if kids can’t or won’t do the program, it doesn’t matter how good it might be.
The researchers also measured kids’ physical fitness, muscle strength, and metabolic health (how their body processes energy) at the start, after four weeks, and after eight weeks of cancer treatment.
Kids with blood cancers receive very strong steroids as part of their treatment, and these steroids can cause serious side effects like muscle weakness, weight gain, and poor fitness. Exercise is known to help prevent these problems in other situations, but nobody knew if it was actually possible to do exercise programs during the intense early weeks of cancer treatment when kids are very sick and in the hospital a lot. This pilot study was important because it tested whether the idea was even realistic before researchers spent time and money on a bigger study.
This study was very small (only six kids), which means the results can’t be trusted to apply to all kids with cancer. The study didn’t meet its own success targets: researchers wanted at least 80% of families to agree to join, but only 67% did. They wanted kids to stick with exercise at least 80% of the time, but only 51% did. They wanted to collect complete measurements from at least 80% of participants, but only 70% completed everything. These low numbers are a red flag that the program design didn’t work well. However, the researchers were honest about these problems, which is actually good science. The study was published in 2026 in Frontiers in Pediatrics, a peer-reviewed journal, meaning other experts reviewed the work before publication.
What the Results Show
The main finding was that this exercise program didn’t work as planned during early cancer treatment. Only two out of six kids actually completed the exercise intervention, and many families dropped out or didn’t stick with the program. The researchers couldn’t properly test whether exercise helped because there weren’t enough kids in the exercise group.
However, the measurements that were completed showed important information about what happens to kids’ bodies during early cancer treatment. Kids lost significant hand grip strength (their hands became much weaker), with measurements dropping about 1.5 standard deviations below normal. Their heart and lung fitness dropped even more dramatically, with peak power output on an exercise bike dropping 3.8 standard deviations below normal. Kids also had trouble with lower body strength, though the results were more mixed for this measure.
Interestingly, when researchers looked at muscle size using ultrasound, the kids’ thigh muscles and belly fat looked mostly normal. This suggests that kids were losing strength and fitness without necessarily losing a lot of visible muscle, which is unusual. The kids also had unpredictable and sometimes unhealthy metabolic states, meaning their bodies weren’t processing energy normally.
Because so few kids completed the study, the researchers couldn’t formally compare whether the exercise group did better than the control group. The pilot data was too limited and variable to draw firm conclusions about exercise benefits.
The study revealed several important challenges that future researchers need to address. Kids and families faced many barriers to participating in exercise during early cancer treatment: the treatment schedule was too demanding, kids were too sick or tired, hospital stays made exercise difficult, and families were overwhelmed with medical appointments. Some kids and staff also had concerns about whether exercise was safe during intense cancer therapy. The researchers found that a one-time nutrition counseling session didn’t seem to engage families much, suggesting that nutrition support might need to be more ongoing and personalized.
Previous research in healthy kids and in kids with other chronic diseases shows that exercise can improve muscle strength, heart fitness, and metabolic health. However, very little research has tested exercise during the intense early weeks of cancer treatment when kids are receiving high-dose steroids and going through induction therapy (the initial aggressive treatment phase). This pilot study is one of the first to try this approach, so there’s limited previous research to compare it to. The findings that kids lose significant fitness during early cancer treatment match what doctors have observed clinically, but this study provides actual measurements to confirm it.
This study has several important limitations. First, it was extremely small with only six participants, so the results can’t be generalized to all kids with cancer. Second, the program didn’t work well enough to properly test whether exercise helps: most kids didn’t complete it, so researchers couldn’t fairly compare the exercise group to the control group. Third, the kids in the study had different types of cancer and different treatment plans, making it hard to know if results apply to specific groups. Fourth, the study only lasted eight weeks during the most intense part of treatment, so we don’t know what happens later. Fifth, the researchers couldn’t measure some important things consistently because kids were too sick or busy with medical care. Finally, the study was done at one hospital, so results might not apply to other hospitals or countries with different treatment approaches.
The Bottom Line
Based on this pilot study, researchers should not yet recommend exercise programs for kids during the first eight weeks of cancer treatment, because the current program design clearly doesn’t work. However, the idea of exercise for kids with cancer is still worth exploring. Future programs should be much more flexible and adapted to kids’ changing medical needs, should involve kids and families in designing the program, should have realistic expectations about participation, and should provide better support to help kids actually do the exercise. Confidence level: Low, because this was a pilot study that didn’t work as planned.
Kids and teens with leukemia or lymphoma and their families should know that this research is still very early and not ready to guide treatment decisions. Doctors and nurses caring for kids with cancer should understand that exercise might help prevent fitness loss, but current programs need major improvements before they’re ready to use in hospitals. Researchers studying cancer treatment should pay attention to the challenges this pilot study identified. Parents of kids with cancer should not try to push their child to exercise intensely during early treatment without talking to their medical team, because this study shows it’s very difficult and we don’t yet know if it’s safe or helpful.
This pilot study only lasted eight weeks, so we don’t know how long it would take to see benefits from exercise if a better program were developed. Based on research in other situations, exercise benefits usually take several weeks to months to become noticeable. However, kids undergoing cancer treatment might see benefits faster or slower depending on how sick they are and how their body responds to treatment.
Frequently Asked Questions
Can kids with cancer do exercise during chemotherapy treatment?
A 2026 pilot study found that current exercise programs don’t work well during early cancer treatment, with only 51% of kids completing the program. However, kids can do gentle movement like short walks on good days, and future programs designed specifically for cancer treatment may help prevent fitness loss.
Does exercise help prevent muscle weakness from cancer steroids?
This pilot study couldn’t prove whether exercise helps because too few kids completed the program. However, the study confirmed that kids do lose significant muscle strength and fitness during early cancer treatment, suggesting that better-designed exercise programs might help prevent these changes.
What happens to kids’ fitness during leukemia or lymphoma treatment?
Research shows kids experience dramatic fitness loss during early cancer treatment, with heart fitness dropping 3.8 standard deviations below normal and hand grip strength dropping 1.5 standard deviations within eight weeks. Interestingly, visible muscle size stayed mostly normal despite the strength loss.
Why did so many kids drop out of the exercise program?
The pilot study identified several barriers: kids were too sick or tired, hospital schedules were too demanding, families were overwhelmed with medical appointments, and there were concerns about exercise safety during intense treatment. These challenges mean future programs need to be much more flexible and realistic.
When should kids with cancer start exercising after diagnosis?
This pilot study only tested the first eight weeks of treatment and found that structured exercise programs don’t work well during this intense phase. Families should talk with their child’s cancer team about when gentle movement might be appropriate, as it varies by individual treatment plan and how sick the child is.
Want to Apply This Research?
- Track weekly hand grip strength using a simple home grip strength meter (available inexpensively online), recording the best of three attempts each week. This single measurement captures overall strength changes and requires only 30 seconds per week.
- Start with very gentle movement like 5 to 10 minute walks on days when energy levels are higher, rather than structured exercise. Use the app to log energy levels before and after movement to identify which times of day work best, then gradually increase duration only if the child feels up to it.
- Create a simple weekly check-in that asks three questions: (1) How many days did you do any movement? (2) How did you feel before and after? (3) Any barriers this week? This builds awareness without pressure and helps identify what actually works for this specific child’s treatment schedule.
This pilot study was very small and did not successfully test whether exercise helps kids with cancer. The findings are preliminary and should not guide treatment decisions. Parents of children with leukemia or lymphoma should always consult with their child’s oncology team before starting any exercise program, as safety and appropriateness depend on the specific child’s medical condition, treatment phase, and overall health status. This research is not a substitute for professional medical advice.
This research translation is published by Gram Research, the science division of Gram, an AI-powered nutrition tracking app.