When a junior player grows before their game does

There is a particular kind of session that every junior tennis coach recognises. A player walks on court looking a little taller than they did before the school holidays. The serve toss is drifting. Their forehand, which used to land heavy and safe, is now flying by a foot. The player looks at the strings, then at the coach, as if the racket has started speaking a slightly different language.

This is one of the ordinary wonders of junior sport. The child is still the same player. Same effort. Same competitiveness. The jokes at the drinks break have not changed. But the body they are using has changed underneath them, and for a while the tennis has to find its way back into that new shape.

The body changes before the feel returns

The adolescent growth spurt is not a small background detail. It is the second fastest period of growth a human body goes through after infancy. Sports scientists often talk about peak height velocity, which is the stretch of time when a child is growing at their fastest. For girls it is often around eleven and a half. For boys it is often closer to thirteen and a half. In that period, a young athlete can grow eight to ten centimetres in a year.

The body does not grow in one neat piece. Legs may lengthen before the trunk. Arms may follow on their own timetable. Feet can look suddenly too big, then suddenly normal again. Two players in the same year group can be a long way apart physically, even if their birthdays sit close together. On paper they are both under thirteen. On court they may be living in entirely different bodies.

There is also a coordination piece. Around the months of fastest growth, fine motor control can dip for a while. Researchers have called this adolescent awkwardness, which sounds casual, but the idea is useful. The brain is updating its sense of where the limbs are, how far the hand travels, how quickly the foot lands, how much space the body now takes up. The player still knows how to play. Their feel is recalibrating.

Why tennis makes growth so visible

Tennis shows these changes quickly because the sport asks for timing at the far end of a long chain. A serve begins in the legs and finishes at the strings. A forehand moves through the hips, trunk, shoulder, arm, hand and racket. When the links in that chain change length, the ball feels it straight away.

A small amount of extra reach can move the contact point enough to change the flight of the ball. The player is not suddenly aiming for the back fence. They are using a body that gives them a little more racket head, a little more stretch, a little more pace than the one they had a few weeks ago. Until the timing adjusts, the ball can arrive late, leave early, or miss by margins that feel bigger than the change that caused them.

Other sports feel it too. Young footballers may notice it in their stride. A swimmer may notice it in the catch. A gymnast may notice it in balance. Tennis gives honest feedback, and it gives it quickly. Balls land in or out. The serve clears the net or it does not. The player gets honest information on every shot, which is useful, but it can also feel exposing when the body is changing fast.

The patterns a coach can look for

The useful thing for a coach is that the wobble often has a pattern. Not a perfect one, because children do not grow from a handbook, but enough of a pattern to help the session stay calm. Depth control on the serve and forehand may shift first. They are big, flowing shots with longer timing windows and plenty of moving parts. The player may still strike the ball well, but with less certainty about where the strike is sending it.

Volleys can feel strange next, because the decision and the contact happen so close together. A racket that used to appear in the right place now arrives slightly tucked in or slightly too far away. Movement may feel a beat behind as well. Longer legs bring new power, but also a new sense of where the feet are going to land. The player is learning the court again through a body that has quietly changed scale.

There is a physical side to watch too. During fast growth, bones can lengthen before the surrounding muscles and tendons feel ready for the new demand. Knees and heels may get more vocal. Some juniors meet Osgood Schlatter around the knee or Sever disease around the heel. Serving players may report a tight lower back or a shoulder that feels heavy. These are moments for attention, not panic. The body is giving information, and a good coach listens early.

What positive coaching looks like here

Good coaching becomes practical here. The player needs the court to feel like a place where they can find their timing again, not a place where every miss becomes a verdict. That does not mean lowering standards. It means choosing the right standard for the season the player is in.

• Bring the target area in for a while, so the player gets honest success while the body recalibrates.
• Use more cooperative rallying, especially early in the session, so the player can build rhythm before score pressure arrives.
• Keep technical language simple. One cue at a time is usually enough when the body is already processing change.
• Adapt the load when knees, heels, backs or shoulders feel sensitive. The programme can stay ambitious and still be kind to the body.
• Notice the small returns. A better contact point. One calmer recovery step. A serve that misses long by less than last week.

The language matters as much as the drill. A junior player does not need a lecture about biomechanics when they are frustrated. They need a coach who can say, without fuss, your body is changing and your timing is coming with it. We are going to give it good repetitions. We are going to keep the work simple. You are still on track.

Why notes matter during growth

A simple coaching record is powerful in these months. Not because every session needs to become medical or complicated. Because patterns are easier to support when they are written down. Height up. Serve depth changing. Heel sore after two hard court days. Forehand timing better when rally starts slower. Confidence brighter after cooperative work. These small notes become the picture.

They also help the parent feel included. A calm parent update can be simple. She has grown quickly this term, so we are seeing the timing move around a little. The ball striking is still there. We are giving her more rhythm work, watching the heel, and keeping the confidence high while it settles. That kind of message does not make the growth spurt bigger than it is. It makes it understandable.

Biological age is part of the picture

Growth also changes how juniors compare with one another. An early maturing player may look powerful for their age. A later maturing player may still be waiting for that strength to arrive. Both players deserve a coaching eye that sees beyond the result in front of them.

Some youth sport environments have experimented with grouping players by biological maturity as well as age, because the difference can be large during adolescence. A solo coach may not control the competition format, but they can still hold that knowledge inside their own practice. The smaller player can be developed with patience and belief. The bigger player can be developed with skill, variety and care. Neither one is finished. Both are still becoming.

The relationship carries the player through

A growth spurt is a season inside a junior career. It can be awkward. It can be funny. Sometimes it is deeply frustrating. It can also be a brilliant time for a player to learn that their game is not as fragile as one difficult month makes it feel.

That is the quiet work of coaching juniors. Notice the change. Name it gently. Adjust the session. Keep the standards alive without making the child feel behind. Remember what happened last week, and the week before that, and the month before that. The tennis matters, of course it does. But the relationship is what helps a young player stay with the tennis while the body catches up.