56. Can run-walk-run help hack zone 2 to unlock more benefit for women?
Stacy Sims, an exercise physiologist and nutrition scientist known for her expertise in female physiology, has provided insights on how women's training should differ from men's due to physiological differences. When it comes to Zone 2 training, which is typically low-intensity endurance training, Sims suggests that women may not need to focus on it as much as men. Here's why:
Hormonal Differences: Women have a different hormonal profile than men, particularly due to the presence of estrogen and progesterone. These hormones impact how women's bodies respond to exercise. Estrogen, for example, allows women to more readily burn fat for fuel at higher intensities compared to men. This means women can train at a slightly higher intensity while still reaping the benefits of what would typically be considered Zone 2 training for men.
Fat Utilization: Women's bodies are more efficient at burning fat as a fuel source compared to men. This means that during endurance activities, women can rely more on fat metabolism even at higher intensities, reducing the need to focus extensively on the low-intensity Zone 2 training that is often used to improve fat oxidation.
Recovery and Adaptation: Women and men recover and adapt to training stimuli differently. The hormonal fluctuations in women, especially in the context of the menstrual cycle, affect recovery and energy utilization. As such, women might benefit more from varied training intensities tailored around their menstrual cycle phases, rather than a consistent focus on Zone 2 training.
Muscle Fiber Composition: Some research suggests that women might have a higher proportion of Type I muscle fibers, which are more endurance-oriented. This could mean that women are naturally more predisposed to endurance, thus requiring less of the traditional Zone 2 training to achieve the same endurance adaptations as men.
Cardiovascular Differences: Women generally have a smaller heart size and lower hemoglobin levels compared to men, which affects how their bodies deliver oxygen to muscles during exercise. This physiological difference can influence the type of training that is most beneficial for women.
Lactate Threshold: Women might have a slightly different lactate threshold response compared to men, influencing how they respond to different training zones.
It's important to note that while these factors suggest differences in training needs between men and women, every individual is unique. Women should consider their personal fitness levels, goals, and responses to training when determining the right mix of training intensities. Additionally, while Zone 2 training might not need to be the primary focus, it still plays an important role in a well-rounded training program for endurance, recovery, and overall cardiovascular health.