Guide
Why runners need single-leg exercises (not just squats)
A squat trains two legs pushing together on stable ground. A run is 160+ single-leg landings per minute, each one a small balance emergency. If you only have two or three strength slots a week, single-leg work buys you more than the barbell does.
What single-leg training fixes that squats can't
Pelvic control. On one leg, your glute medius has to hold your pelvis level. In a two-leg squat it barely works. A dropping pelvis is behind a lot of runners' knee and IT band pain.
Left-right gaps. Almost everyone has a stronger leg. Two-leg lifts let the strong side quietly take over; single-leg lifts expose and close the gap before it becomes an overuse injury on the weak side.
Balance under fatigue. Late in a race your form doesn't fail because your muscles are weak — it fails because your stabilizers are cooked. Single-leg training trains exactly those.
The five worth doing
1 · Rear-foot-elevated split squat. The king. Big strength stimulus, built-in balance demand, and a hip-flexor stretch for the trailing leg. Bodyweight first; add dumbbells when 10 clean reps feel easy.
2 · Single-leg Romanian deadlift. Hamstrings and glutes as brakes and balancers. Keep the hips square and the reach slow — wobbling is part of the training effect, not a failure.
3 · Step-up. Hill running in exercise form. Whole foot on the box, drive through the heel, control the descent. The eccentric lowering is half the value.
4 · Single-leg calf raise. The calf-Achilles unit handles more load than any other tissue in running. A useful benchmark: 20+ smooth single-leg raises per side. Most runners test far below it.
5 · Side plank. Technically zero legs — but it trains the same lateral chain that keeps you stacked over one foot, which is the part of the core that actually earns its place in a runner's week.
How to fit them into a running week
Two sessions a week is enough for most runners: one on a non-running day, one as a 20-minute add-on after an easy run. Keep hard things apart — heavy single-leg work the day before intervals ruins both workouts. And progress load slowly: add reps first, then weight, never both at once.
Get a week built around your schedule
The free builder places single-leg strength sessions around your actual running days — intervals and long runs protected — and picks exercises for your equipment and pain history.
Rather have it on paper? Get the printable Starter Week PDF — free, emailed to you, no card.
Next read: A 12-week strength plan for marathon training · Strength training for runners without a gym
General information, not medical advice. Train within pain-free range and get persistent issues assessed by a professional.