Running Size: Optimizing Stride, Cadence, and Biomechanics

What is the best running size?

The "best running size" primarily refers to the optimal interplay between your stride length and stride rate (cadence). While highly individual, an efficient running gait generally involves a shorter stride coupled with a higher cadence to minimize impact forces and enhance performance.

Understanding "Running Size": Stride Length vs. Stride Rate

In exercise science and biomechanics, when we discuss "running size," we are largely referring to the characteristics of your stride: its length and its frequency. These two parameters are intrinsically linked and inversely proportional.

• Stride Length: This is the distance covered from the point one foot makes contact with the ground to the next time the same foot contacts the ground. A longer stride means you cover more ground with each step.
• Stride Rate (Cadence): Also known as cadence, this is the number of steps you take per minute (SPM). A higher stride rate means you are taking more steps in a given amount of time.

An optimal running size isn't about maximizing one at the expense of the other, but rather finding a harmonious balance that promotes efficiency, reduces injury risk, and supports performance goals.

The Biomechanics of an Optimal Stride

An efficient running stride is characterized by several key biomechanical principles that work together to propel you forward with minimal wasted energy and impact.

• Minimizing Ground Contact Time: The less time your foot spends on the ground, the less braking force is applied, and the more efficiently you can transition to the next stride. An efficient stride feels "light" and "quick."
• Appropriate Foot Strike: While there's ongoing debate, a midfoot or forefoot strike is generally advocated over a pronounced heel strike. A midfoot strike allows the foot to act as a natural shock absorber, distributing impact forces more effectively through the kinetic chain. Heel striking, especially when overstriding, can create significant braking forces and increase stress on joints.
• Reduced Vertical Oscillation: This refers to the amount your body bobs up and down with each stride. Excessive vertical oscillation means energy is being wasted moving upwards rather than purely forwards. An efficient runner maintains a relatively stable head and torso height.
• Avoiding Overstriding: This is perhaps the most common biomechanical error. Overstriding occurs when your foot lands significantly in front of your body's center of mass, often with a straight or locked knee. This creates a powerful braking force, increases impact stress on the knees, hips, and lower back, and reduces running economy. It's often associated with a lower stride rate and longer stride length.
• Effective Hip Extension and Knee Drive: Powerful hip extension at the push-off phase and a coordinated knee drive forward are crucial for propulsion. This comes from strong glutes, hamstrings, and hip flexors.

The Magic Number: Cadence (Stride Rate) Recommendations

For many years, the benchmark for an optimal running cadence has been around 180 steps per minute (SPM). This number originated from observing elite runners and their high stride rates.

• Why 180 SPM? While not a strict rule, a higher cadence (closer to 170-180+ SPM for most runners) is often associated with:
  • Reduced Impact Forces: A shorter stride naturally leads to softer landings directly under the body's center of mass.
  • Less Overstriding: Increasing your cadence often forces you to shorten your stride, thereby reducing the likelihood of overstriding.
  • Improved Running Economy: By minimizing braking forces and vertical oscillation, less energy is wasted, making you more efficient.
  • Lower Injury Risk: Less impact and better force distribution can reduce stress on joints and tissues.

It's important to note that 180 SPM is a guideline, not a rigid target for everyone. Taller runners or those running at very high speeds might naturally have slightly lower or higher cadences, respectively. The goal isn't to hit an arbitrary number but to find your optimal cadence that feels efficient and comfortable.

Optimizing Your Running Size: Practical Strategies

Adjusting your running size, particularly increasing your cadence, should be a gradual process to allow your body to adapt.

• Listen to Your Body: Pay attention to how your current stride feels. Does it feel heavy? Do you feel a jarring impact? These could be signs of overstriding or inefficient mechanics.
• Use a Metronome or Running Watch: Many running watches have built-in cadence trackers. Alternatively, a simple metronome app can be set to your target SPM, and you can try to match your steps to the beat.
• Shorten Your Stride, Increase Your Cadence: This is the primary actionable advice. Consciously take smaller, quicker steps. Imagine "running over hot coals" or "running lightly."
• Focus on Foot Strike: Aim for a gentle midfoot landing directly beneath your hips, rather than reaching out with your heel.
• Incorporate Running Drills: Drills like A-skips, B-skips, high knees, and butt kicks help reinforce good posture, improve coordination, and train quicker leg turnover.
• Strengthen Key Running Muscles: Strong glutes, hamstrings, quadriceps, and core muscles are essential for supporting an efficient stride. Incorporate exercises like squats, lunges, deadlifts, and planks into your routine.
• Plyometrics: Exercises like box jumps and jump squats can improve your body's elasticity and power, contributing to a quicker ground contact time.
• Gradual Adaptation: Don't try to drastically change your cadence overnight. Increase your SPM by 5-10 steps at a time over several weeks, allowing your muscles and connective tissues to adapt to the new movement pattern.

Beyond Biomechanics: Other Factors Influencing "Best" Size

While biomechanics are central, other factors also influence what constitutes an optimal running size for you at any given moment.

• Terrain: Running uphill might naturally shorten your stride and increase your cadence, while downhill running might allow for a slightly longer stride with controlled braking. Trail running demands more adaptable stride patterns than flat road running.
• Pace/Effort: A sprint will naturally involve a much higher stride rate and different stride length than a long, slow endurance run. Your "best" size will vary with your intensity.
• Individual Anatomy: Factors like limb length, flexibility, and natural joint mobility can influence your ideal stride characteristics.
• Injury History: Runners with specific injury histories (e.g., patellofemoral pain, shin splints) may benefit significantly from cadence adjustments to alter load distribution.
• Running Goals: Are you training for a marathon (efficiency paramount) or a short sprint (power and speed)? Your "best" stride will adapt to these goals.

Conclusion: The Dynamic Nature of the "Best" Running Size

There is no single, universal "best running size" that applies identically to every runner in every situation. Instead, the optimal running size is a dynamic interplay between your stride length and stride rate, tailored to your individual physiology, current fitness level, and specific running goals.

By understanding the biomechanical principles of an efficient stride, focusing on increasing your cadence, and gradually implementing changes, you can refine your "running size" to become a more efficient, powerful, and injury-resilient runner. It's an ongoing journey of self-awareness and continuous improvement.