The decision to defer, not start (DNS), or not finish (DNF) a goal race is never easy. It requires thoughtful planning, emotional maturity, and a willingness to adjust expectations. Knowing when to toe the line and when to step away is essential for long-term success in endurance sports.

I have been in a few events the past 33 years since I started triathlon and have had one DNF, 1996 age group Nationals in Orange County California. I was injured and struggling running the swim to the bike, t1, and while biking the hilly terrain, and then when I exited t2, I decided to quit. Looking back, I should have walked the 10k to finish.

Racing, even when you know you won’t set a personal record (PR), is still a valuable experience. Having the tools to navigate when to defer, DNS, or DNF can help you make the best choice for your physical health and mental well-being.

Reasons to Defer a Race

Deferring a race means postponing participation, often due to circumstances outside your control. Common reasons include:

• Pregnancy
• Injury (e.g., broken bones or unmanageable pain)
• Significant life changes (family, finances, or work)
• A change in race date
• Loss of motivation or a shift in goals

Because races are often registered for far in advance, your personal goals or life circumstances may change. You don’t owe anyone an explanation—if deferring supports your mental and physical health, it’s the right choice.

Before deferring, consider options like switching distances (e.g., opting for a half marathon instead of a full) or adjusting your race day goals to align with your current fitness level.

When to DNS (Did Not Start)

Unlike a deferral, which usually happens ahead of time, a DNS is often a race-day decision. Common reasons include:

• The deferral deadline has passed
• Cost concerns (travel, hotel, race fees)
• Minor injuries or illness
• Over-registration or treating the race as low-priority (like a local 5K fun run)

Starting a race injured or unprepared can lead to more harm than good. If racing jeopardizes your recovery or overall health, it’s smarter to sit it out.

However, DNS should not be your fallback because of fear. Fear of not performing well—or not PRing—is not a valid reason to avoid the start line. Racing when you’re not at your best teaches resilience and builds confidence.

Addressing the Fear of Failure

One of the biggest mental blocks athletes face is the fear of underperforming. It’s tempting to avoid racing when you know you won’t hit a goal time.

Failure is part of the process. Racing outside your comfort zone, even when it’s scary, leads to mental growth and success. You may not PR, but showing up is a win in itself.

If you’ve qualified for a once-in-a-lifetime event like the Boston Marathon or Ironman World Championship, don’t let perfectionism rob you of the experience. Get to the start line with the best version of yourself on that day.

When It’s BEST to DNF (Did Not Finish)

Valid and smart reasons to stop mid-race include:

• Heat exhaustion or dehydration
• Injury or sharp pain
• Signs of serious medical issues (dizziness, blurred vision, chest pain)

Your safety comes first. Know the difference between discomfort and danger. If continuing the race could lead to serious consequences, DNFing is maturity.

That said, if you’re struggling due to poor pacing or execution, consider slowing down or walking rather than quitting. Many finish-line regrets come not from poor performance but from giving up too soon.

Have a Flexible Race Day Plan

Being mentally and physically prepared includes having more than one goal. Consider building:

• Plan A: Your best-case outcome
• Plan B: A realistic middle-ground goal
• Plan C: A finish-at-all-costs scenario

Also, if available, consider switching to a shorter distance race on the day.

Managing expectations is a crucial part of endurance racing. Whether you defer, DNS, or DNF, make sure your decision supports your long-term goals and health. Sometimes, the bravest thing an athlete can do is not race or adapt to a race execution with where you are at.

You don’t have to explain your choice to anyone but yourself. Just make sure it’s a choice made with intention, not fear.