There's a kid in your U10s squad who's head and shoulders taller than everyone else. Faster. Stronger. Wins every tackle. Scores most of the goals. The parents of the other kids mutter about it being "unfair." His own parents are already wondering about academy trials.
Fast forward four years. That same kid is now average height. The others caught up physically. And because he spent three years relying on size and speed rather than learning to play, he's suddenly behind. The technical, decision-making stuff he never needed? He needs it now. Badly.
This is exactly why the physical corner sits at just 10% in the FA Four Corners model. Not because physical development doesn't matter — it does. But because over-valuing it at young ages creates a set of problems that coaches, parents, and players all pay for later.
What the physical corner actually means
Let's clear something up first. The physical corner at youth level is NOT about fitness training. It's not about running laps. It's definitely not about beep tests for 8-year-olds. Please don't do beep tests with 8-year-olds.
At grassroots ages, the physical corner covers:
Movement skills — agility, balance, coordination. Can the kid change direction without falling over? Can they jump and land properly? Can they move sideways and backwards, not just forwards?
Body awareness — do they know where their body is in space? Can they shield a ball? Can they adjust their body position to receive a pass?
Appropriate physical activity — are they getting enough movement in sessions? Are the games energetic enough that they're naturally developing stamina without anyone mentioning the word "fitness"?
Physical safety — are they warming up properly? Is the session design appropriate for their age and stage?
Notice what's missing from that list. Strength training. Speed work. Endurance runs. Anything that treats an 8-year-old like a small adult. Because they're not.
Why 10% is the right number
The weighting feels low to some coaches. Especially ex-players who grew up with "get fit or get dropped" mentalities. But there are two really solid reasons the physical corner sits where it does.
Reason one: biological unfairness. Kids develop physically at wildly different rates. You'll have U10s who range from looking like U8s to looking like U12s. If you weight the physical stuff heavily, you're basically rewarding early developers and punishing late ones. That's not coaching — it's a birth date lottery.
Research on relative age effect backs this up hard. Kids born in September (start of the school year) are significantly over-represented in academy systems compared to August-born kids. Not because they're better footballers. Because they're up to 11 months more physically mature. The system is biased towards bigger, faster, earlier developers. A 10% physical weighting fights against that bias.
Reason two: physical advantages are temporary. That big, fast U9? Their advantage shrinks every year as the other kids catch up. If all they've developed is physicality, they've got nothing to fall back on. The late developer who spent those years getting technically better, making smarter decisions, and building confidence? They're the ones who'll be the better player at U14, U16, and beyond.
The "just let them play" approach to physical development
Here's the good news. If your sessions are well-designed — lots of small-sided games, active involvement for everyone, minimal standing in lines — you're already covering 90% of what the physical corner needs at youth level.
Kids don't need a fitness programme. They need to play. A lot. In different ways.
Small-sided games (3v3, 4v4, 5v5) are physically intense by nature. Every player is constantly moving, changing direction, accelerating, decelerating. That's better physical development than any drill you could design.
Add in some coordination work at the start of sessions — ladders, cone weaves, jumping patterns — and you've covered the movement skills piece. Keep it to five minutes. Make it fun. Don't call it "fitness" or half the kids will switch off before you've started.
What to watch out for
There are a few physical development red flags that grassroots coaches should be aware of:
The kid who's always exhausted. If a player is struggling to get through a normal session, that's worth a conversation with their parents. It might be nothing — late night, skipped lunch. Or it might flag something worth checking.
The kid who's growing fast. Growth spurts cause all sorts of coordination issues. A kid who was technically sharp suddenly can't control the ball because their legs grew three inches over summer. Be patient. It passes. Don't mistake temporary clumsiness for regression.
The kid who never stops running. Sounds positive, right? But sometimes the kid who runs everywhere is compensating for poor positioning or decision-making. They're working twice as hard because they're always in the wrong place. Physical effort is masking a tactical problem.
Over-training. Some kids play for their school, a Sunday team, a Saturday team, and do extra sessions. That's a lot of physical load for a developing body. It's not your job to manage their entire schedule, but if a kid is playing five or six times a week and looking tired, it's worth flagging.
How to track physical development properly
Because the physical corner is weighted at just 10%, it's easy to ignore it entirely. That's a mistake. Low weighting doesn't mean unimportant — it means proportional.
You should still be noting physical development markers: improvements in coordination, better balance during turns, growing confidence in their body. These are just as trackable as a cleaner first touch, especially if you use something like InsideFooty to log observations across all four corners after each session. The 10% weighting is applied automatically, so you don't have to think about the maths — you just record what you see.
The conversation you'll need to have with parents
At some point, a parent will ask you why their physically dominant kid isn't getting singled out for praise. Or why you're not running fitness sessions. Or why the smaller kid keeps getting picked ahead of their larger child.
Be ready for that conversation. Explain that physical advantages at U8-U12 are temporary and unreliable. Explain that the kids who develop all four corners — especially the psychological and technical ones — are the kids who succeed long-term. And explain that protecting late developers from being written off at age 9 because they're small is one of the most important things youth football can do.
Most parents get it when you put it that way. They want what's best for their kid. They just need someone to explain what "best" actually looks like at this age.
And it's not running laps.