Key Takeaways
- Exercise may do more than build muscle—it could help the body release growth hormone naturally.
- This test suggests that short, intense activity might replace drugs in diagnosing GH deficiency.
- Children who generated more power during the test were more likely to show normal GH levels.
- If validated, this approach could reshape how we test—and think about—growth hormone in both kids and adults.
Short Stature In Children
Human growth hormone, AKA HGH, GH, and somatotropin, is essential for a child’s healthy growth and development. When the body doesn’t produce enough, a condition known as growth hormone deficiency (GHD), children may experience slow growth, delayed puberty, or low muscle mass.
Diagnosing GHD, however, isn’t simple. The standard method involves growth hormone stimulation tests, where medications like clonidine, glucagon, or arginine are used to provoke GH release. These procedures are often time-consuming, require multiple blood draws, and can cause side effects like dizziness, nausea, or low blood sugar, making them stressful for children and families alike.
But what if there were a better way? A study published in Growth Hormone & IGF Research suggests that a short, high-intensity cycling workout may trigger the same GH response, without the use of medication. If validated, this approach could offer a faster, safer, and more natural alternative for diagnosing GH deficiency in children.
The Study: Can Exercise Do the Job?
A research team in Israel, led by Dr. Nitzan Dror, explored whether high-intensity interval exercise (HIIE) could serve as a natural, drug-free trigger for GH release.
Who Was in the Study?
- 17 children (average age 12.4) with slower-than-normal growth
- All had previously completed drug-based GH stimulation tests
What Did They Do?
The researchers created a child-friendly version of high-intensity interval training (HIIT)—a workout that alternates bursts of intense effort with brief recovery. Known in this context as HIIE, this method is already known to stimulate GH in adults.
Each child performed a cycling test involving:
- 10 short bursts of all-out pedaling (15 seconds each)
- 1-minute active rest between intervals
- Resistance tailored to age, sex, and body weight
- Supervision by trained pediatric staff
Blood samples were taken before and after the workout to measure GH levels.
What the Study Found
- The exercise triggered a significant rise in GH levels, similar to drug-based stimulation.
- Children who generated more than 10 watts per kilogram of body weight showed a higher likelihood of a normal GH response.
- 83% of these high-output children reached GH levels consistent with healthy growth.
While promising, this was a small pilot study. More research is needed with larger, more diverse populations to validate these results.
Why This Could Be a Game-Changer
Exercise-based testing offers several advantages over traditional GH stimulation:
- No medication or IVs required
- Fewer side effects
- Shorter test time—often under one hour
- A more natural hormone response
- Potentially less stressful for children
However, not every child may be eligible. Children with muscle weakness, fatigue, or certain disabilities may not be able to perform the test at the needed intensity.
Is It Safe and Practical?
Yes—under medical supervision. This wasn’t a regular gym workout:
- Protocols were customized to each child’s physical status
- Performed on stationary medical bikes in a clinic setting
- Total effort time was just 10 minutes
- No serious side effects were reported
“This approach mimics real-life hormone production, which makes it more physiologically relevant,” said Dr. Dan Nemet, a pediatric endocrinologist and study co-author.
Limitations to Consider
- Some children may not generate enough power for the test to be reliable
- Requires trained staff and specialized equipment
- GH secretion varies with stress, nutrition, and sleep
- Still considered experimental—not yet approved for widespread clinical use
What Parents Should Know
If your child is undergoing testing for growth concerns, ask your pediatric endocrinologist about all diagnostic options. While this HIIT-based test is not yet standard, it’s a potential alternative, especially for kids who struggle with or cannot tolerate medication-based testing.
“We’re not replacing medications yet,” Dr. Nemet noted. “But this is a big step toward safer, simpler hormone testing.”
Remember: no single test confirms GHD. A diagnosis typically includes clinical symptoms, growth history, IGF-1 levels, and stimulation test results.
FAQs
What is human growth hormone (GH)?
It’s a hormone made by the pituitary gland that drives growth, metabolism, and development, especially in kids.
What’s the difference between HIIT and HIIE?
HIIT is a fitness term. HIIE is the clinical version used in studies—same concept, just more controlled and medically supervised.
Why do doctors test for GH levels?
To check if a child’s short stature or slow growth is caused by a deficiency in GH.
How is GH usually tested?
Through stimulation tests using medications that “force” the body to release GH for measurement.
What drugs are used in GH stimulation tests?
Clonidine, glucagon, and sometimes insulin or arginine. Each comes with risks and side effects.
What are the downsides of those drug-based tests?
They take hours, can make kids feel sick or dizzy, and need close medical monitoring.
What’s different about this new test?
It uses high-intensity interval exercise (HIIT) to stimulate GH release for diagnostic testing, not for treatment, and avoids the need for drug-based stimulation.
What exactly did the kids do in the study?
They cycled hard for 15 seconds at a time, rested a minute, and repeated that 10 times—under medical supervision.
Does High-Intensity Interval Exercise really work?
In this small study, yes—GH levels rose just as much as they did during drug tests.
Is this safe for kids?
Yes, when done under proper supervision. No major side effects were reported.
Could this replace standard GH tests?
Not yet. More research is needed. But it’s a promising future option.
Can adults use HIIT to boost GH too?
Yes, studies show HIIT can spike GH in adults, but not for medical diagnosis purposes.
Does this mean people should use HIIT instead of HGH injections?
If you’re using HGH off-label for anti-aging or fat loss, this study reminds us that your body may already have a natural way to boost GH.
What about kids with physical disabilities—can they do this test?
Not always. It requires a minimum level of strength and equipment, so it’s not for everyone.
Is this a treatment for GH deficiency?
No—it’s a diagnostic tool, not a therapy.
Does this mean exercise can treat GH deficiency?
No. This test helps diagnose GH function. Children with true GH deficiency still require medical treatment, often including hormone therapy.
The Bottom Line
This study does more than introduce a novel testing method—it challenges the traditional approach to growth hormone diagnosis. If exercise can reliably provoke GH release, it may pave the way for drug-free diagnostic tools that are faster, safer, and less invasive.
The findings also have implications for the anti-aging and weight-loss communities, where synthetic HGH is often used off-label in hopes of improving muscle mass, fat loss, or vitality. While this study doesn’t support that use, it highlights the body’s natural ability to raise GH through structured, intense physical effort. For adults chasing GH for metabolic benefits, HIIT may offer a science-backed, safer path than injections.
In pediatrics, this method could one day help avoid stressful, medication-heavy protocols for diagnosing growth issues. But until larger clinical trials confirm its reliability, this test remains investigational.
Still, this research marks a turning point: one that favors harnessing the body’s own systems, rather than overriding them with medication. That shift could transform not only how we diagnose GHD, but how we understand hormonal function across all of endocrinology.
Reference
Dror, N., Pantanowitz, M., Nemet, D., & Eliakim, A. (2021). High-intensity interval exercise test stimulates growth hormone secretion in children. Growth Hormone & IGF Research, 57–58, 101388. https://doi.org/10.1016/j.ghir.2021.101388
