Sex Differences in Physical Performance
What are the key differences in men and women and how does it impact training?
The study "Sex differences in physical performance: A systematic review and meta-analysis" published in The Journal of Physiology (PMID: 39106346) investigates the performance disparities between males and females across various physical activities.
Key Findings
Performance Disparities: The analysis reveals that males generally outperform females in strength and power-related activities, with an average performance difference of about 20-30%. This gap is particularly pronounced in activities like weightlifting and sprinting.
Endurance Events: In endurance sports, the performance gap narrows, with females showing comparable or even superior performances in certain long-distance events, potentially due to physiological differences such as fat metabolism.
Physiological Factors: The Differences in muscle mass, hormonal influences (particularly testosterone), and body composition contribute significantly to the observed performance disparities.
Muscle Mass and Fiber Type
Males have larger muscle fibers, with type-I fibers accounting for 36% of the total biopsy area compared to 44% in females. Type-IIA fibers account for 41% in males and only 34% in females.
Type-I fibers are 19% larger, type-IIA fibers are 59% larger, and type-IIX fibers are 66% larger in males than females.
Testosterone stimulates bone growth and increases bone density, leading to larger and more robust skeletons in males with thicker bones in the legs, arms, and shoulders.
Bone Density and Fracture Risk
Males tend to have higher bone density and content, achieving it at a later age compared to females.
In the majority of populations, males have larger and stronger bone and joint surfaces and more bone at muscle attachment sites.
Women are more likely to experience fractures of the hip, wrist, and spine, while men are more likely to experience fractures of the hip, pelvis, and upper leg bone.
Red Blood Cells and Hemoglobin
Males have higher red blood cell (RBC) count, hematocrit, and hemoglobin concentration compared to females.
RBC count is highest in males throughout the intervention period, followed by females taking hormonal contraceptives (HC) and then females not taking HC.
Heart and Lungs
The female heart has a smaller cardiac output than the male heart due to smaller ventricular volumes, despite attempting to compensate with a higher heart rate.
The female heart has a larger ejection fraction and beats at a faster rate but generates a smaller cardiac output compared to the male heart.
Women tend to have shorter, narrower rib cages than men, which is why women's waists appear narrower than men's
Age and Training Effects: The performance gap tends to decrease with age, suggesting that training and conditioning can mitigate some differences. Additionally, the impact of training regimens is more pronounced in females, indicating that tailored training programs could enhance their performance.
Related
Practical Takeaway
Understanding the physiological differences in performance can inform training strategies for both males and females. Coaches and trainers should consider these disparities when designing programs, focusing on maximising individual strengths while addressing specific areas for improvement. This approach can lead to more effective training outcomes and foster a more inclusive environment in sports.
Reference
Hunter, S. K., & Senefeld, J. W. (2024). Sex differences in human performance. The Journal of Physiology, 602(17), 4129-4156. https://doi.org/10.1113/JP284198