MoPro
TrainersEye · The Growing Athlete · Ages 10–16
Growing Athlete J
Trainer's Eye
Phase 3 · Build strength · Session J

One leg.
Both sides.
No favourites.

Sport makes lopsided athletes. Single-leg work is where the difference shows — and where it gets fixed.

  • Jsession
  • P3Strength
  • 12:00on the clock
  • — donecompleted

Sever's disease

Heel pain at the back of the heel in an active child aged roughly eight to fourteen is calcaneal apophysitis. Calf strength and load management are the treatment.

Ten per cent is the line

A strength or hop difference of more than about ten per cent between sides is worth training out.

Back pain is not normal

Persistent back pain in a young athlete is not something to train through. It needs assessing — young spines have their own specific problems.

Three couplets · two rounds · twelve minutes · available all season

A

One leg

Split squat + Bulgarian split squat
A1

Split squat

60 s · slow reps

Long stance; lower straight down until the back knee nearly touches, torso tall.

Easier hold a chair  ·  Harder hold a bag

R1R2—
A2

Bulgarian split squat

8/side · ×2

Rear foot on a chair; lower straight down with the front heel flat and the chest up.

Easier split squat on the floor  ·  Harder hold a bag

R1R2
B

Hips

Single-leg bridge + hip thrust
B1

Single-leg bridge

60 s · slow reps

One foot down, the other knee hugged in; drive up with the hips completely level.

Easier two feet  ·  Harder 3-s hold

R1R2—
B2

Hip thrust

12 reps · ×2

Shoulders on a chair, chin tucked; drive the hips to a level line and squeeze.

Easier floor bridge  ·  Harder hold a bag

R1R2
C

Calves

Single-leg heel raise + calf endurance
C1

Single-leg heel raise

60 s · slow reps

Fingertips on a wall for balance; rise onto one toe and lower slowly, swapping at thirty seconds.

Easier two legs  ·  Harder off a step

R1R2—
C2

Calf endurance set

25 reps · ×2

Twenty-five full-range heel raises; stop at the last one that reaches the top.

Easier two legs  ·  Harder one leg

R1R2

The clock

Round 1settle in — 70%, perfect tracking
0:00A1 → A2
2:00B1 → B2
4:00C1 → C2
Round 2own it — beat Round 1 by quality
6:00A1 → A2
8:00B1 → B2
10:00C1 → C2

Each couplet: 60 s scored → the loading set → 10 s to move on. Done at 12:00.

How to run it

  1. Strength training is safe for young athletes when it is supervised and technique-led. It does not stunt growth — that is a myth.
  2. Start with your own body weight. Add load only when every repetition looks the same as the first.
  3. Two clean sessions at a level earn the next. Add the harder version, not more repetitions.
  4. Train both sides. The side you push off, throw with or land on is not the only one that matters.

Tick it off

MovementRound 1Round 2Best
A1Split squatslow reps in 60 s —
A2Bulgarian split squat8/side
B1Single-leg bridgeslow reps in 60 s —
B2Hip thrust12 reps
C1Single-leg heel raiseslow reps in 60 s —
C2Calf endurance set25 reps
Session time
StreakDay —
Client / Patient
Coach / Clinician signature
Date
TE-12-GROWINGAT-J