For runners, the right pair of shorts can make a significant difference in comfort and performance. Unlike casual shorts, running shorts are engineered for movement, moisture management, and minimal distraction during your run. Whether you're training for your first 5K or preparing for a marathon, understanding what to look for in running shorts will help you find a pair that supports your goals.

After testing countless running shorts over 15 years of competitive and recreational running across Australia's diverse conditions, I've developed a clear understanding of what features matter and which are merely marketing fluff. This guide shares that knowledge to help you make an informed choice.

The Great Liner Debate: Built-In vs. Unlined

Perhaps the most divisive topic in running shorts is the built-in liner. These lightweight inner briefs are designed to provide support and eliminate the need for separate underwear. Understanding your preference here is crucial before shopping.

Built-In Brief Liners

Traditional running shorts feature a built-in brief that resembles lightweight underwear. These liners provide support, reduce chafing, and wick moisture away from sensitive areas. Most runners who grew up with these shorts swear by them, appreciating the secure fit and reduced layering.

Compression Liners

A more recent development, compression liners are longer and fit more snugly than brief liners. They extend partway down the thigh, providing muscle support and virtually eliminating inner-thigh chafing. Many runners find these more comfortable for longer distances, though they can feel warmer in hot conditions.

Unlined Shorts

Some runners prefer shorts without any liner, wearing their preferred underwear or compression shorts underneath. This option offers maximum flexibility but requires careful pairing to avoid chafing. If you have specific underwear preferences or find liners uncomfortable, unlined shorts are worth considering.

Runner's Tip

Never test new running shorts on race day. Wear them for at least several training runs of similar distance to ensure they won't cause issues when it counts. What feels fine for 5km might become problematic at 20km.

Inseam Length: Finding Your Sweet Spot

Running shorts inseam lengths typically range from 3 to 7 inches. The right length for you depends on your body type, running style, and personal preference.

Short Inseam (3-4 inches)

Racing splits and very short shorts offer maximum freedom of movement and minimal fabric interference. They're popular among competitive runners and those who run in hot conditions. However, they show more thigh and may feel exposed to some runners. The shorter length also means less sun protection for your legs.

Medium Inseam (5-6 inches)

This is the most popular range for recreational runners. Medium-length shorts provide good leg freedom while offering more coverage and sun protection. They're versatile enough for everything from speed work to long runs and work well across different weather conditions.

Longer Inseam (7 inches)

Some runners prefer longer shorts for added coverage and sun protection, particularly during longer runs where sun exposure accumulates. However, longer shorts can feel heavier when wet with sweat and may cause more friction against your thighs during extended running.

Inseam Selection Guide
  • For racing and speed work: Consider 3-4 inch inseams for minimal interference
  • For general training: 5-6 inch inseams offer the best versatility
  • For long runs in sun: 5-7 inch inseams provide better protection
  • For hot conditions: Shorter inseams allow more airflow

Fabric Technology That Matters

Running shorts fabrics have evolved significantly. Understanding what different technologies actually do helps you separate genuine performance features from marketing terminology.

Moisture-Wicking

This is non-negotiable for running shorts. Moisture-wicking fabrics pull sweat away from your skin and spread it across the fabric surface where it can evaporate. This keeps you drier and more comfortable, and prevents the heavy, waterlogged feeling of cotton. Look for polyester or nylon as base materials, as both offer excellent wicking properties.

Quick-Drying

Related to moisture-wicking, quick-dry fabrics minimise the time your shorts stay wet. This matters for comfort during humid conditions or longer runs where you'll accumulate significant sweat. It's also practical for travel when you might need to wash and dry shorts overnight.

Lightweight Construction

Every gram counts over a marathon. Quality running shorts use lightweight fabrics that don't sacrifice durability. The best shorts feel almost weightless when dry and don't become heavy anchors when wet with sweat.

Four-Way Stretch

Fabrics with four-way stretch move with your body in all directions, providing unrestricted range of motion. This is particularly important for runners with longer strides or those who incorporate dynamic movements into their training.

Fabric Warning

Avoid cotton running shorts entirely. Cotton absorbs moisture, becomes heavy when wet, dries slowly, and dramatically increases chafing risk. Even cotton blends should be avoided for serious running. Stick with synthetic fabrics designed for athletic performance.

Essential Features for Runners

Beyond the basics, several features can enhance your running experience depending on your needs.

Pocket Placement and Security

Consider what you carry on runs. A small back pocket or zippered pocket can secure a key or card without bouncing. Some shorts feature phone-sized pockets with secure closures for runners who like to carry their device. Waistband pockets work well for gels during long runs.

Reflective Elements

If you run in low-light conditions, reflective detailing is essential for safety. Look for reflective logos, trim, or panels that remain visible without adding bulk. Many quality running shorts incorporate reflective elements subtly into the design.

Adjustable Waistband

An internal drawstring allows you to fine-tune the fit. This is particularly important for longer runs when your waist size might change slightly, or if you like to carry items in a waistband pocket without the shorts slipping down.

Split Design vs. V-Notch

Some running shorts feature side splits that allow greater leg extension. Split shorts offer maximum range of motion and are popular among faster runners. V-notch designs provide extra freedom at the outer leg while maintaining a more traditional appearance.

Choosing Shorts for Australian Conditions

Australia's climate presents unique considerations for runners. Our summers can be brutally hot, and many runners train in conditions that would be considered extreme elsewhere.

Heat Management

For hot Australian summers, prioritise maximum ventilation. Lighter colours reflect more heat, mesh panels increase airflow, and shorter inseams expose more skin for cooling. Some premium shorts feature ventilation zones specifically designed to promote airflow.

Sun Protection

Consider UPF-rated fabrics for long training runs in peak UV conditions. While shorts alone won't provide complete sun protection, UPF-rated materials add an extra layer of defence for covered skin. This becomes increasingly important for ultra-distance runners spending hours in the sun.

Versatility for Variable Weather

Australian weather can change quickly. Medium-weight shorts in the 5-6 inch range tend to work well across conditions, from cool morning starts to warm afternoon finishes. Having a couple of pairs suited to different conditions is worthwhile if you run year-round.

Investment and Value Considerations

Running shorts range from budget options under $30 to premium pairs exceeding $100. While expensive doesn't always mean better, quality running shorts are worth the investment for serious runners.

Consider cost-per-wear rather than just purchase price. A $80 pair of shorts that lasts three years of regular use and remains comfortable throughout is better value than multiple cheaper pairs that wear out quickly or never feel quite right. Quality construction, durable fabrics, and thoughtful design justify higher prices.

That said, beginners don't need to start with top-tier options. Mid-range shorts from reputable athletic brands offer excellent performance at reasonable prices. As you develop preferences through experience, you can invest in premium options that match your specific needs.

Caring for Your Running Shorts

Proper care extends the life of your running shorts and maintains their performance properties. Wash shorts after each use in cold water with mild detergent. Avoid fabric softeners, which can coat moisture-wicking fabrics and reduce their effectiveness. Air dry when possible, or use low heat in the dryer.

For detailed washing and care instructions, see our complete guide on caring for activewear shorts.

Final Recommendations

The perfect running shorts are those you forget you're wearing. They should support your movement, manage moisture effectively, and never cause distraction or discomfort. Take time to find shorts that work for your body type, running style, and typical conditions.

Don't hesitate to try multiple brands and styles. Runners often develop strong preferences for specific brands once they find what works. Your ideal shorts might be different from what works for other runners, and that's perfectly fine. The goal is finding what helps you run your best.