Parents who call about training for a teenager tend to arrive from one of two directions. The kid plays a sport and something keeps flaring up, usually a knee or a shoulder, and the flare-ups are getting closer together. Or the kid has mostly stopped moving, the parent can see where that leads, and they want to interrupt it before it sets.
Both situations point at the same underlying question, which is what the teenager can control with their own body right now. That question gets skipped a lot. The default in teen training is to hand a fifteen year old a version of an adult program with lighter weights on the bar, then add weight as they get comfortable. The kid does get stronger. What they often do not get is any better at owning the positions their sport and their life are going to demand from them.
Growing bodies lose range before they lose anything else
Something happens through a growth spurt that catches coaches off guard if they have not watched it before. Long bones lengthen quickly. The soft tissue crossing those bones adapts on a slower timeline. For a stretch of months, a kid who could sit in a deep squat at thirteen cannot get near it at fourteen, and nothing about that is a strength problem.
The usual read on this is tightness, so the hamstrings get stretched and the hip flexors get stretched and the kid goes back to practice. Range comes back a little. It goes away again by the next week.
What changed is where the joint has control, and control has to be trained at the range you want, not assumed to follow along behind flexibility. A teenager going through peak growth is also getting new limb lengths delivered to them faster than their nervous system is updating the map. Coordination gets temporarily worse in kids who were coordinated a year earlier. That is a normal part of maturation and it resolves, though how it resolves depends a fair amount on what they are doing during it.
This is the window where joint capacity is cheapest to build. Tissue is adapting anyway. Adding intelligent load and end-range work while the body is already remodeling costs less effort than trying to claw the same range back at thirty-five. That principle sits underneath Functional Range Conditioning and it is most of the reason we start teenagers at the joint instead of at the movement pattern.
Load is safe when somebody is coaching it
The old worry about teenagers lifting weights, that it stunts growth or wrecks growth plates, has been examined thoroughly and does not hold up. The 2014 international consensus on youth resistance training concluded that appropriately designed and supervised resistance training is safe for children and adolescents, and that it improves strength, motor skill, and bone health (1).
Read the qualifiers in that sentence, because they carry the whole thing. Appropriately designed. Supervised. The injuries that do show up in youth lifting cluster around unsupervised max attempts, technique nobody corrected, and load added faster than the kid could control it. Safety is a coaching variable rather than a property of the barbell.
So the question for a parent lands on who is watching the reps and what they are watching for. A coach who can see a knee drifting in on rep six, and who knows the difference between a kid who needs a cue and a kid who needs less weight, changes the risk profile more than any programming decision.
One sport, twelve months a year
The other thing worth naming is exposure. Austin teenagers play year-round club schedules in volleyball, soccer, baseball, and increasingly tennis and pickleball, and the season no longer has an off ramp built into it.
A case-control study of young athletes found that those who were highly specialized in a single sport had higher odds of serious overuse injury, and that athletes training more hours per week than their age in years carried elevated injury risk as well (2). The second number is a useful one to hold in your head. A fourteen year old training twenty hours a week is well past it.
Nobody is going to pull their kid off the club team because of a case-control study, and I would not ask them to. What is available is the rest of the week. If a shortstop spends every practice in the same three positions, the training block outside practice is where the other positions get maintained. Rotation to both sides. Hips through their full range rather than the ninety degrees the sport keeps asking for. Overhead work for a kid whose sport lives below the shoulder. This is the actual argument for prehab and injury prevention training in a teen athlete, The argument is about coverage. Nobody here thinks the kid is fragile.
What we look at before writing anything
Every teenager starts with an assessment, and the reason is boring: we do not know what their joints can do until we measure it. A parent’s description of the problem and the coach’s read on the problem are frequently different, and the kid’s own report is filtered through wanting to keep playing.
We are looking for the gap between what a joint can be moved through passively and what the teenager can produce actively on their own. That gap is where most of the interesting information lives. A shoulder with a hundred and eighty degrees of passive flexion and a hundred and forty of active flexion is telling you something specific about what happens when that arm gets loaded overhead at speed. The movement assessment we run with athletes is built to find those gaps. Grading a squat tells you much less.
From there the program tends to write itself. The ranges with the biggest gaps get the work. The ranges that hold up get maintained and loaded. We retest, because a number that has not moved after eight weeks means the program was wrong and should change.
Where teenage confidence comes from
Parents ask for confidence often, and it is a reasonable thing to want. It does not come from being told they are doing great.
What builds it in a sixteen year old is watching a number change that they know they earned. Six weeks ago the bar was empty and the depth was ugly. Now there is weight on it and the depth is clean. They were there for every session in between, so the evidence is theirs and it holds up under their own scrutiny in a way that encouragement does not.
This is also why we explain what we are doing and why, at whatever level of detail the kid will tolerate. A teenager who understands the reason behind a drill keeps doing it when nobody is watching, which is a large part of why we do not just hand people a list of exercises.
When a teen wants to change how they look
Some families come in because a teenager wants to lose weight or look different, and that motivation is normal enough that dismissing it does not help anybody.
We keep the training pointed at capacity and strength, and we let appearance be a thing that changes along the way while the sessions get graded on something else. Teenagers who train for performance generally end up looking the way they wanted to anyway, with the difference that the habit survives.
If a teenager’s relationship with food or with their body looks like it has moved past ordinary self-consciousness, that belongs with a physician or a therapist who works with adolescents. It is outside what a training relationship should be handling, and saying so early is better than discovering it later.
Starting
Teenagers do not need a perfect program. They need a coach paying attention to what their joints can do this month, which is different from what those joints could do last year and different again from what they will do next year.
If your teen is already training and something keeps flaring, or they are about to start and you would rather they start with a map, a Functional Range Assessment is where we begin. For teens who are already active and need structured joint work alongside their sport, KINSTRETCH covers that in a class setting.
References
- Lloyd RS, Faigenbaum AD, Stone MH, et al. Position statement on youth resistance training: the 2014 International Consensus. Br J Sports Med. 2014;48(7):498-505.
- Jayanthi NA, LaBella CR, Fischer D, Pasulka J, Dugas LR. Sports-specialized intensive training and the risk of injury in young athletes: a clinical case-control study. Am J Sports Med. 2015;43(4):794-801.
Written by
Brian Murray, FRA, FRSC
Founder of Motive Training
Motive Training is a coaching studio in South Austin built around assessment, joint health, and strength you can use. Train with us in the studio, come to a KINSTRETCH class, or work through the progressions in KINSTRETCH Online.