Why Your Soccer Player Got Slower After a Growth Spurt (And What Actually Fixes It)

A player grows three inches over a season. Everyone expects them to get faster, stronger, harder to knock off the ball. Instead they get slower. Heavier legs, a step off the pace, a first touch that used to be automatic and now isn't. And the most confusing part is that nothing about their effort changed. They're training as hard as ever, maybe harder, and the results are going the wrong direction.

If you have watched this happen and quietly wondered what got missed, the answer is almost never what most people assume. It usually isn't a fitness problem, a motivation problem, or a sign the athlete plateaued. It's a fueling problem that hides in plain sight during one of the most demanding stretches a young body will ever go through. And once you can see it, it's one of the more fixable things in youth sports.

Growth is the most expensive thing a young body will ever do

We tend to think of a growth spurt as something that just happens on its own, quietly, in the background. Physically, it's anything but quiet. Building new bone, new muscle, and a bigger frame takes an enormous amount of energy, and during a spurt that construction project is running at full speed.

Now layer training on top of it. A competitive soccer player is already asking a lot of their body between practices, games, and conditioning. During a growth spurt, they're doing that on top of the most energy-hungry building phase of their life. Two full-time jobs, running at the same time, both drawing from the same fuel tank.

Here's what almost nobody gets told. When the fuel coming in doesn't cover both jobs, the body does not split the shortage evenly. It has a priority order, and growth wins. The body will protect getting bigger and staying healthy first, and it quietly pulls energy away from the systems that drive performance. Recovery slows down. The hormonal signaling that turns hard training into actual progress gets dialed back. The result is an athlete growing on schedule but playing below where they were, with no idea why.

A 2025 review in the journal Nutrients laid out exactly this dynamic. It described how young athletes carry the energy demands of growth, maturation, and training all at once, and how falling short on total fuel undermines both development and performance. The takeaway is simple. When the plate doesn't keep up with the growth, performance is the first thing the body gives up.

The trap: eating like the smaller version of themselves

The reason this is so common comes down to a mismatch in timing. When an athlete hits a growth spurt, the amount of fuel their body needs jumps up fast. Their appetite, their habits, and their sense of a normal portion do not automatically jump with it.

So they keep eating the way they did a year ago. The same breakfast they've had since middle school, or no breakfast at all before a full school day. The same dinner portion. A small snack after a two-hour training session that used to be plenty and no longer is. None of it looks wrong on any given day, which is exactly why it slips past everyone.

That is the part worth sitting with. It cannot be spotted in a single meal. One slightly-too-small lunch looks completely fine. It's the weeks of small shortfalls stacking up that eventually surface as heavy legs, a slower first step, and fading in the back half of games. By the time the performance drop shows up, the cause has been quietly building for a month or more.

The same Nutrients review noted that young athletes frequently fail to meet the energy their growth and training actually require, often without anyone realizing a gap exists. This is not a story about not trying hard enough. It's a story about demand rising faster than habits, and nobody catching the drift until it shows up on the field.

What the fix actually looks like

The good news is that the solution is refreshingly boring, and it works. It is not about overhauling anything or going on a diet. It is about letting the plate grow with the athlete. Three practical shifts carry most of the load.

Carbohydrate is the fuel that gets cut first and missed most

Carbs power the repeated sprints, the pressing, and the high-effort actions that define soccer, and a growing body leans on them even harder than an adult's does. When fuel runs short, carbs are usually the first thing to fall away, and their absence shows up fast as flat, sluggish play.

The move is to build a real carbohydrate source into every meal, and to add more on training and game days. Rice, pasta, oats, potatoes, bread, and fruit are the workhorses here. The goal is to treat them as the base of the meal rather than a small side.

Protein is usually a timing problem, not a total problem

Most young athletes already eat plenty of protein. In fact, research on adolescent athletes has found they often eat two to three times the protein their bodies need. While need and optimal are two different things, even at the optimal level intake tends to be on the higher end. That's one reason protein powders and "growth" supplements rarely add anything real. The catch is that most of that protein tends to arrive at dinner, in one large serving.

A growing body is building and repairing around the clock, not just at night. Spreading protein across the day gives it a steadier supply to work with. Something at breakfast, something at lunch, something after training, rather than one big pile in the evening. This single shift often does more than any supplement money could buy.

Do not cut fat to chase a leaner look

This is the one that trips people up during the exact years it matters most. Fat carries dense energy in a small volume. That's valuable for a growing athlete who needs a lot of fuel and can only eat so much at once. It also supplies the raw materials the body uses to build the hormones that drive growth and development. Pulling fat out during a growth spurt is one of the fastest ways to accidentally send the whole system into a deficit. Nuts, seeds, avocado, olive oil, fatty fish, and nut butters all earn their place on the plate.

Underneath all three shifts sits one rule that makes them work. The overall plate simply has to be bigger than it was a year ago. Same foods the athlete already likes, more of them, spread through the day.

The three nutrients that quietly run low while growing

Beyond total fuel, a growth spurt pulls hard on a few specific micronutrients right when the body needs them most. The 2025 Nutrients review flagged iron, calcium, and vitamin D as the three that deserve the most attention during adolescence.

Iron demand climbs during these years to support rapid growth and a bigger blood volume. When it runs low, it looks exactly like ordinary tiredness, which is why it gets missed. Fatigue, fading late in games, and foggy focus can all trace back to it. The primary food source is red meat and pairing that with a vitamin C food helps the body absorb more. This is a primary reason why vegetarians/vegans are very susceptible to iron deficiency.

Calcium matters because the pubertal growth spurt is a one-time window to build bone density, and the need is higher during these years than it will ever be again. Getting a calcium food into most meals, from yogurt and milk to fortified plant milks and cooked greens, is one of the highest-return habits of this whole stretch.

Vitamin D helps the body actually use that calcium, and it supports muscle recovery. It tends to run low in athletes who train indoors, live through dark winters, or stay covered up in the sun. Fortified milk, eggs, and fatty fish provide some through food. This is one area where a doctor may check levels and recommend more.

When aches show up alongside the growth spurt

One more thing worth naming, because it connects directly to fuel. Knee pain and heel pain that show up right as an athlete shoots up in height are not random bad luck. During a spurt, bones lengthen faster than the muscles and tendons attached to them can keep pace. That leaves those tendons pulling tight over fast-growing bone. A 2014 review in Orthopaedics and Traumatology: Surgery and Research described this as the mechanical basis for the common overuse injuries seen in growing athletes, concentrated in the knees and heels. It also made a point worth hearing. Pain during sport is a warning sign, not something normal to push through.

Fuel does not replace rest, smart training loads, or a doctor's evaluation when pain shows up. But an under-fueled body is trying to repair fragile, still-growing tissue without enough materials to do the job well, which is why fueling belongs in the conversation alongside managing the training load. It's the lever most people overlook.

The bigger picture for the late developer

For the smaller, later-developing player on the team right now, this is the part worth holding onto. At the same age, the more physically mature player tends to win the sprint tests and the jump tests, and it's easy to read that as a talent gap. But research on elite youth soccer players keeps finding something different. That early advantage tracks with biological maturity, not age on paper, and it fades in older age groups as the rest of the field catches up. One study of nearly seven hundred elite academy players found that later-developing players, despite being less physically mature, showed no meaningful gap in strength, speed, or technical soccer skill.

The window while the body catches up is not wasted time. It's when the skill that lasts gets built, and when good fueling makes sure that when the growth does arrive, it arrives strong instead of depleted. The gap on the field today is a snapshot, not a scoreboard.

-----------

Frequently Asked Questions

Why did my soccer player get slower after growing taller? During a growth spurt, the body spends enormous energy building a bigger frame while also fueling training. When total fuel falls short, the body protects growth first and pulls back from performance systems like recovery, so an athlete can grow and get slower at the same time. Increasing overall food, especially carbohydrate, usually brings performance back.

How much more should a growing athlete eat? There's no single number that fits everyone, and calorie targets are not the useful tool here. The practical rule is that the plate should be noticeably bigger than it was a year ago, with a carbohydrate source at every meal, protein spread across the day, and fat kept in rather than cut. Appetite sometimes doesn't keep up so scheduled real meals can be helpful to ensure adequate intake.

Do growth or height supplements actually work for young athletes? No supplement adds height. Growth is driven by genetics and by having enough total fuel to support it. Most young athletes already eat well above their protein needs, so powders rarely add anything the food isn't already providing. The money is almost always better spent on groceries.

Should I be worried about knee or heel pain during a growth spurt? Growth-spurt aches in the knees and heels have a known mechanical cause, but pain during sport is a signal to checkin, not to push through. It's worth getting evaluated by a doctor, while also making sure the athlete is fueling and recovering well and not overloading a fast-growing frame.

How do I know if my athlete needs more than food adjustments? If fatigue, heavy legs, or foggy focus stick around no matter how well an athlete is eating, that's the point to involve a doctor for bloodwork. Iron and vitamin D in particular can run low during growth. A sports dietitian can also help map out a fueling plan built around an athlete's growth stage and schedule. That's exactly what a free 15-minute Discovery Call with Rise Nutrition is designed to discuss.

-----------

Is your athlete growing fast and you want tomake sure their fueling is actually keeping up with how quickly their body ischanging? A free 15-minute Discovery Call is where we can discuss if workingwith Rise can help map out a plan built around their growth stage, trainingload, and schedule, so a growth spurt becomes an advantage instead of asetback.  Book Your Discovery Call

Jay Short, MS, RD, CSSD is a Registered Dietitian and Board Certified Specialist in Sports Dietetics, and co-owner of Rise Nutrition, specializing in sports dietetics for competitive athletes. He works with US Soccer (all 27 teams), the Columbus Blue Jackets (NHL), and athletes across MLS, collegiate, and club programs.

-----------

References

1. Everett S. Optimizing Performance Nutrition for Adolescent Athletes. Nutrients. 2025;17(17):2792. https://pubmed.ncbi.nlm.nih.gov/40944181/
2. Launay F. Sports-related overuse injuries in children. Orthop Traumatol Surg Res. 2014;101(1 Suppl):S139-S147. https://pubmed.ncbi.nlm.nih.gov/25555804/
3. Wenger M, Csapo R. Relative age effect and biological maturation in Austrian elite youth soccer players. Front Sports Act Living. 2025;7:1583880. https://pubmed.ncbi.nlm.nih.gov/40313785/
4. Bezuglov E, Malyakin G, Emanov A, et al. Are Late-Born Young Soccer Players Less Mature Than Their Early-Born Peers, Although No Differences in Physical and Technical Performance Are Evident? Sports (Basel). 2023;11(9):179. https://pubmed.ncbi.nlm.nih.gov/37755856/