What is an important consideration when using resistance training to enhance running performance?

In the context of enhancing running performance through resistance training, balancing resistance training with endurance work is essential. This approach ensures that while strength is being developed, it does not detract from the runner's endurance capacity, which is crucial for performance.

Integrating resistance training can help improve strength, power, and biomechanics, leading to improved running efficiency and reduced injury risk. However, if resistance training is emphasized to the exclusion of endurance work, it may lead to fatigue during long runs or races, diminishing overall performance. Therefore, a well-rounded training program that incorporates both elements is necessary for optimal results.

The other options do not fully address the complexity of training for runners. Focusing solely on upper body strength ignores the importance of lower body strength critical for running. While flexibility exercises are beneficial, they do not directly contribute to the necessary balance of strength and endurance. Limiting strength training to once a week may not provide sufficient stimulus for strength adaptation, reducing the potential benefits of incorporating resistance training into a runner's regimen. Balancing both resistance and endurance training maximizes the benefits and supports overall performance development in running.