Bike Shorts: What to Wear (and Not Wear) Underneath for Optimal Comfort and Hygiene

What do guys wear under bike shorts?

For optimal comfort, hygiene, and performance, men typically wear nothing under their bike shorts. The shorts, specifically the integrated chamois pad, are designed to be the primary and only layer against the skin.

The Golden Rule: Go Commando (Usually)

The overwhelming consensus among cyclists, exercise scientists, and apparel manufacturers is that bike shorts are designed to be worn without underwear. This might seem counter-intuitive to those new to cycling, but there are compelling physiological and biomechanical reasons behind this practice. The specialized construction of cycling shorts renders traditional underwear not only unnecessary but also detrimental to comfort and skin health during a ride.

Why Going Commando is Recommended: The Science Behind It

Several key factors contribute to the recommendation of wearing nothing under bike shorts:

• Elimination of Chafing and Friction: Underwear, regardless of material or style, has seams. These seams, when pressed between the skin and the saddle during the repetitive motion of pedaling, create significant friction points. This friction can lead to painful chafing, skin irritation, rashes, and even open sores (commonly known as saddle sores). Bike shorts, conversely, are designed with minimal seams, especially in the crotch area, and those present are flat-stitched to prevent irritation.
• Superior Moisture Management: Cycling shorts are constructed from technical synthetic fabrics (e.g., Lycra, spandex blends) that are highly effective at wicking moisture (sweat) away from the skin. The integrated chamois pad also possesses excellent moisture-wicking and quick-drying properties. Wearing underwear, particularly cotton, traps moisture against the skin. A damp environment is a breeding ground for bacteria and fungi, significantly increasing the risk of skin infections, folliculitis, and saddle sores.
• Optimized Chamois Function: The chamois (or cycling pad) within the shorts is engineered to provide cushioning, reduce pressure points, and manage moisture directly against the skin. It often has antimicrobial properties. Wearing underwear creates an additional, unnecessary layer that interferes with the chamois's ability to perform these functions effectively, negating its benefits.
• Enhanced Breathability: High-quality bike shorts and chamois are designed for maximum breathability, promoting airflow to keep the skin cool and dry. Underwear can impede this airflow, leading to increased heat and moisture buildup in a sensitive area.

Understanding Bike Shorts: Chamois and Fabric

To fully appreciate why underwear is redundant, it's essential to understand the components of quality bike shorts:

• The Chamois (Cycling Pad): This is the crucial element. Modern chamois pads are multi-density, anatomically shaped inserts made from advanced synthetic foams and fabrics. They are designed to:
  • Cushion: Absorb road vibrations and provide padding for sit bones.
  • Reduce Pressure: Distribute pressure evenly across the perineal area.
  • Manage Moisture: Wick sweat away from the skin and dry quickly.
  • Prevent Bacteria: Often infused with antimicrobial treatments.
  • Seamless Interface: Designed to be the direct contact layer with the skin.
• Technical Fabrics: The body of the bike shorts is typically made from stretchy, compressive, and moisture-wicking synthetic fabrics like Lycra, spandex, nylon, or polyester blends. These fabrics move with the body, provide support, and facilitate evaporative cooling.

Exceptions to the Rule: When Underwear Might Be Considered (and What Kind)

While the "go commando" rule is paramount for serious cycling, there are very limited scenarios where an alternative might be considered, though always with caveats:

• Casual, Short Rides (e.g., Commuting in Regular Clothes): If someone is wearing baggy mountain bike shorts or casual cycling shorts over their regular clothes for a very short, low-intensity commute, they might keep their regular underwear on. However, this is distinct from wearing padded road cycling shorts for athletic purposes.
• Hygiene Concerns (Misconception): Some individuals might feel uncomfortable with the idea of "going commando" for perceived hygiene reasons. It's crucial to emphasize that the cleanliness of the bike shorts themselves is paramount. Freshly washed bike shorts are far more hygienic than wearing a layer of potentially damp, bacteria-laden underwear underneath.
• Specific Medical Advice: In extremely rare cases, a medical professional might advise a specific undergarment for a pre-existing skin condition. This would be an exception directed by a doctor.

If one absolutely must wear something (against best practice), it should be:

• Briefs or Boxer Briefs (NOT Boxers): Loose-fitting boxer shorts will bunch up and cause severe chafing. If any underwear is worn, it should be a snug-fitting brief or boxer brief style that minimizes fabric movement.
• Synthetic, Seamless Fabric: Avoid cotton at all costs. Opt for athletic-specific underwear made from moisture-wicking, synthetic materials with flat or minimal seams. Even then, it will likely compromise the performance of the bike shorts.

Consequences of Wearing Underwear Under Bike Shorts

Ignoring the "go commando" rule can lead to several uncomfortable and potentially serious issues:

• Saddle Sores: The most common and painful outcome. These are skin lesions, boils, or infections caused by friction, pressure, and moisture.
• Chafing and Rashes: Constant rubbing from underwear seams against sensitive skin.
• Folliculitis: Inflammation or infection of hair follicles, often appearing as small red bumps or pimples.
• Increased Risk of Infection: Trapped moisture and heat create an ideal environment for bacterial and fungal growth.
• Reduced Comfort and Performance: The underwear interferes with the chamois, leading to less effective padding and moisture management, making rides less enjoyable and potentially cutting them short.

Proper Care of Bike Shorts

Since the chamois is the direct interface with the skin, maintaining its cleanliness is vital for hygiene and preventing skin issues.

• Wash After Every Ride: Bike shorts should be washed immediately after each use.
• Cold Water & Gentle Cycle: Use cold water and a gentle cycle with a mild detergent.
• Avoid Fabric Softeners: Fabric softeners can clog the technical fibers, reducing their wicking ability.
• Air Dry: Hang dry or lay flat. Avoid high heat from a dryer, as it can damage the elastic fibers and the chamois padding.

Key Takeaways for Optimal Comfort and Performance

For any male cyclist aiming for comfort, hygiene, and peak performance, the message is clear:

• Wear nothing under your bike shorts.
• Trust the chamois: It's designed to be your skin's direct interface.
• Prioritize cleanliness: Always wear freshly washed bike shorts.
• Invest in quality: Good bike shorts with a well-designed chamois are worth the investment for preventing discomfort.

By adhering to this fundamental principle, cyclists can significantly enhance their riding experience, prevent common skin irritations, and focus on the road ahead.