What Is the Hole in Men's Underwear For?

Have you ever noticed that small, often overlooked opening at the front of men's underwear? Commonly referred to as the "fly," this design feature has a surprisingly long history, dating back to the 19th century. Initially incorporated into men's underwear as practicality met modesty, the fly was meant to allow men to urinate without fully undressing—critical at a time when clothing was far more cumbersome. The fly can be found on different types of men's underwear including both boxers and briefs.

In the late 1800s, men's undergarments were designed with convenience in mind, as noted by historians. According to fashion historians like Valerie Steele, director of The Museum at the Fashion Institute of Technology, the underwear fly became popularized when clothing was layered and difficult to remove.

Functional Convenience or Fashion Statement?

Today, while underwear designs have evolved considerably, the fly remains a popular, albeit debated, feature. A survey conducted by underwear brand Tommy John found that approximately 80% of men rarely or never use the fly for its intended purpose. Despite this, it continues to be a standard inclusion in men's underwear, often as much a matter of tradition and aesthetic as functionality.

Interestingly, newer brands occasionally forgo the fly entirely, opting for streamlined designs without compromising comfort. Thus, the fly's continued presence suggests an intersection between practicality and consumer expectation.

Health Implications: Hygiene and Comfort

Medically speaking, the fly also presents some hygiene considerations. According to Dr. Michael Eisenberg, a urologist at Stanford University, underwear choice and design can impact genital health. Breathability and ease of access can potentially reduce moisture build-up, decreasing risks of irritation, fungal infections, or skin conditions like jock itch.

Yet, Dr. Eisenberg emphasizes that choosing underwear made from breathable, natural fibers like cotton or moisture-wicking fabrics remains more crucial for hygiene and comfort than the presence of the fly itself.

Psychological Aspects of Underwear Design

Underwear design, including the fly, also has psychological implications. Fashion psychologists suggest that seemingly trivial design choices can significantly influence body confidence and perceived masculinity. Dr. Carolyn Mair, author of "The Psychology of Fashion," notes that small features like the underwear fly reinforce traditional masculinity narratives, signaling practicality and readiness.

This psychological dimension explains why the fly persists in designs, even as practical usage wanes—it's a subtle reminder of culturally reinforced gender norms.

Modern Innovations and Alternatives

With changing cultural attitudes and innovations, alternatives to the traditional underwear fly have emerged. Companies like Saxx and Mack Weldon have introduced designs focusing on ergonomic comfort and support rather than easy-access features. These modern designs often include pouches or panels specifically engineered for comfort and movement, indicating that today's consumers value comfort and fit over historical practicality.

Market research firm Statista notes a steady increase in men's comfort-focused underwear market, expected to grow annually by 5.3%, reaching $11.2 billion by 2026. This underscores the evolving priorities of consumers, reflecting broader shifts in men's fashion toward functionality and health-conscious choices.

Boxers vs. Briefs: Which One Should You Choose?

Choosing between boxers and briefs goes beyond personal style—it's a decision with implications for health, comfort, and lifestyle. While both have their merits, scientific studies and medical experts offer insights to help you decide.

• Boxers:
  • Pros:
    • Improved ventilation, reducing heat and moisture buildup.
    • Potentially better for fertility; a study in Human Reproduction found that boxer-wearers have 25% higher sperm concentration compared to brief-wearers. This may not result in thicker cum, but it can help with sperm motility.
    • More comfortable for daily wear due to looser fit. Some men with big balls report more a more comfortable fit from boxers.
  • Cons:
    • Less support during physical activities.
    • Can bunch or ride up, causing discomfort under fitted clothing.
• Briefs:
  • Pros:
    • Enhanced support, ideal for sports and active lifestyles.
    • Reduces friction and provides stability during physical movements.
    • More streamlined appearance under tight clothing.
  • Cons:
    • Increased heat retention, potentially affecting fertility.
    • Higher risk of moisture accumulation, which may lead to skin irritation or infections if fabric choice is not breathable.

Experts from institutions like the Mayo Clinic emphasize personal comfort, breathability, and lifestyle as key decision-making factors (5). The best underwear is the one that makes you feel most comfortable, suits your daily activities and athletics, and aligns with your own health situation.

Sources:

1. https://stanfordhealthcare.org/publications/415/415875.html
2. https://www.ncbi.nlm.nih.gov/search/research-news/7979/
3. https://www.ncbi.nlm.nih.gov/search/research-news/675/
4. https://pmc.ncbi.nlm.nih.gov/articles/PMC6214186/
5. https://www.mayoclinichealthsystem.org/hometown-health/speaking-of-health/boxers-or-briefs-4-common-fertility-myths-debunked