It can happen quickly, often when a young rider has been racing well. Six months ago, they looked smooth and coordinated and were hitting their lines cleanly. Now they look stiff coming out of the gate, slightly slower and less comfortable on the bike.
I've watched this happen with young riders throughout my 40 years in BMX. Sometimes it's a technical issue or accumulated fatigue. During the growing years, a rapid growth spurt can also play a role.
As a young rider's body changes, their flexibility, coordination and movement control can temporarily change with it. That's why mobility and flexibility deserve a regular place in their training rather than being treated as an afterthought.
Why Do Growing Kids Get Tight So Quickly?
Short answer: rapid growth can temporarily change how muscles, tendons and joints move together.
During a growth spurt, bones can lengthen rapidly while the surrounding muscles and tendons take time to adapt. This can temporarily affect flexibility, range of motion and coordination.
You might notice:
- Tighter hamstrings or hip flexors
- Reduced ankle movement
- Difficulty getting into their usual gate position
- Temporary clumsiness on the bike
- Soreness around the knees, heels or hips
This doesn't mean your rider has suddenly lost their ability or stopped working hard. Their body may simply be adjusting to a period of rapid change.
Does Stretching Help Young BMX Riders?
Short answer: yes, when it forms part of a properly structured training program.
Regular mobility and flexibility work can help a growing rider maintain the movement they need on the bike. It isn't about turning a BMX rider into a gymnast. It's about ensuring their hips, hamstrings and ankles can move comfortably through the ranges BMX demands.
Mobility work should sit alongside appropriate strength training, workload management and recovery. Together, these elements help young riders move well and continue developing as their bodies change.
Is It Bad to Stretch Before a Race?
Short answer: longer static stretches immediately before an explosive effort aren't the best choice.
Static stretching involves holding one position for an extended period. Longer static stretches, particularly those held for more than 60 seconds per muscle group — can temporarily reduce strength and power when performed immediately before an explosive effort.
That's not what you want just before a gate drops.
Short static stretches included within a complete warm-up appear to have much less effect. However, the main focus before racing should be a progressive dynamic warm-up that raises body temperature, moves the joints through their usable range and prepares the rider for explosive movement.
What's the Difference Between Static and Dynamic Stretching?
Short answer: prioritise dynamic movement before riding and save longer static stretches for afterward or a separate mobility session.
Dynamic mobility involves actively moving through a range of motion. Examples include:
- Leg swings
- Walking lunges
- Controlled hip circles
- Ankle rocks
- Squats and split squats
- Progressive jumps or short accelerations
These movements belong in the warm-up before gate practice, sprint training or racing.
Static stretching involves easing into a position and holding it. Longer static stretches are generally better suited to after training or a separate mobility session. This allows your rider to work on flexibility without potentially reducing their explosiveness immediately before riding.
When Should a Young Rider Start a Mobility Routine?
Short answer: before tightness becomes a problem.
Mobility work shouldn't only appear once a rider is already sore or has lost range of motion. Building the habit early makes it easier to maintain as their training load increases and their body changes.
It doesn't need to be complicated. A short, consistent routine targeting the hips, hamstrings and ankles can fit into a rider's warm-up, recovery work or home training.
The Bottom Line
Mobility and flexibility aren't the flashy parts of a BMX training program. Nobody stands beside the track cheering for a hip flexor stretch.
But for a growing rider, mobility work still has an important job. It helps them maintain the movement needed for a strong gate position, efficient pedalling and confident bike handling as their body develops.
The key is knowing what to do, when to do it and how to adjust it as your rider grows.
That structure is built into every HRVfit program according to the rider's age and stage of development. If you want individual programming adjusted specifically for your rider, take a look at the HRVfit Speed Method.
Explore the HRVfit Speed Method
If you're looking for structured monthly programming with mobility already included, explore Junior Development.
— Tony Harvey
6× Australian BMX Champion
References
Bone growth velocity relative to muscle-tendon unit lengthening during adolescent growth spurts — mechanism of transient flexibility and coordination changes during rapid growth.
Growth plate vulnerability during periods of rapid growth and association with overuse musculoskeletal soreness in youth athletes.
Acute Effects of Static Stretching on Muscle Strength and Power. Frontiers in Physiology, 2019 — static stretching durations over 60 seconds per muscle group associated with measurable declines in subsequent strength and power output; shorter static stretches within a full warm-up show substantially less effect.
Meta-analysis of dynamic warm-up protocols and athletic performance outcomes — dynamic warm-up associated with improved performance versus static stretching or no warm-up.