Why Single-Leg Training (Bulgarian Split Squats) Matters Especially for Endurance Athletes

Introduction

Think about it: running is alternating single-leg landings, cycling is alternating single-leg pedal pushes, and swimming’s kick is also alternating single-leg movements. Yet 99% of people in the gym train with bilateral squats. If your training pattern looks nothing like your sport’s movement pattern, the carryover is naturally diminished. Single-leg training fills this gap, and the Bulgarian Split Squat (BSS) is the quintessential exercise for it.

Three Key Benefits of Single-Leg Training

1. Balances Left-Right Asymmetry

Most endurance athletes have a “dominant leg”—one that pushes harder on the pedals or spends more time on the ground while running. Bilateral training allows the strong leg to compensate for the weak leg, making the gap worse over time. Single-leg training forces each side to produce force independently, automatically exposing and correcting asymmetry.

2. Improves Dynamic Stability

Standing on one leg requires greater engagement of the hip abductors and core stabilizers (such as the gluteus medius and obliques)—muscles that bilateral training tends to neglect but that are crucial for maintaining stable running form and cycling position.

3. Reduces Spinal Loading

The Bulgarian Split Squat requires only about 60% of the load of a bilateral squat to achieve the same per-leg stimulus. This makes it especially friendly for athletes with lower-back discomfort or disc issues.

Bulgarian Split Squat Technique Points

1. Place the rear foot on a bench (approximately knee height)
2. Position the front foot 60–80 cm from the bench (adjust based on height)
3. Slightly lean the torso forward, keeping weight on the front heel
4. Lower until the rear knee lightly touches the ground
5. Drive through the front heel to stand up

Common Errors and Corrections

Program Recommendations

• Beginner Phase (4 weeks): Bodyweight 3 sets × 8 reps/leg, learn the movement
• Development Phase (6 weeks): Dumbbells 3 sets × 8 reps/leg, add weight weekly
• Advanced Phase: Barbell back squat version 4 sets × 6 reps/leg
• Power Phase: Split jumps 3 sets × 5 reps/leg (not performed within 6 weeks of race day)

Practical Tips

• Remember to test both sides: Every 4 weeks, test your 5RM and compare the left-right difference
• Train the weak leg first: Always start with the weak side and do 1 extra set
• Schedule it away from running: BSS places high eccentric stress on the hamstrings; separate it from long-run days by 48 hours
• Add unilateral loading variations: Hold a dumbbell on the side opposite the weak leg to challenge anti-lateral-flexion core strength

Conclusion

The Bulgarian Split Squat is called “the single best exercise for runners” for good reason. It combines strength, balance, mobility, and core stability in one movement, and requires minimal equipment—a chair at home is enough. Starting today, put it in your program twice a week, and in three months you’ll feel a difference in lower-limb symmetry and stability like never before.

Related Reading

• Strength Exercises for Runners: Single-Leg Deadlift, Bulgarian Split Squat, Step-Ups
• Squats for Runners: Transfer Effects of Single-Leg vs. Bilateral Squats on Running
• The Power of Single-Leg Training: Improving Bilateral Imbalances and Enhancing Performance
• Single-Leg and Unilateral Load Training: Correcting Left-Right Imbalances and Functional Transfer for Endurance Athletes