After 15 years of coaching runners in San Diego, I've watched hundreds of people take their first strides toward a goal — a first 5K, a Boston Qualifier, or just a healthier relationship with movement. And almost every time, the same three mistakes show up early, quietly derailing progress before a runner even realizes what's happening. Here's my podium: the top three mistakes I see new runners make, and what to do instead.
🥉 Bronze: Not Getting Fitted for Shoes
Bronze goes to a mistake that seems small but has an outsized impact: grabbing whatever running shoe looks good or is on sale, instead of getting properly fitted. Every runner's foot strikes the ground differently, some overpronate, some underpronate, some have high arches, some have flat feet. The wrong shoe for your mechanics doesn't just feel uncomfortable; it's one of the most common hidden causes of shin splints, plantar fasciitis, and knee pain in new runners.
What to do instead: Get fitted at a specialty running store where staff can actually watch you walk or run and match you to a shoe built for your mechanics. It's a 20-minute investment that can save you months of injury recovery. I send all my runners to Milestone Running in North Park because they provide top notch service, elite knowledge, and great patience through the fitting process.
🥈 Silver: Following the Advice of Your Friend Who's Run "A Bunch of 5Ks"
Silver goes to one of the most common, and best intentioned mistakes out there: taking training advice from a well-meaning friend who's run a handful of 5Ks. I get it. That friend is enthusiastic, encouraging, and has real experience. But "a bunch of 5Ks" doesn't equal an understanding of training principles, injury prevention, or how to build a program around your specific goals, background, and body.
Generic advice like "just run more" or "you'll be fine, I never stretch" might have worked for your friend, but everyone's history, mechanics, and recovery capacity are different. What builds one runner up can break another one down.
What to do instead: Lean on your friend for motivation and company on runs, that's invaluable. This applies to your favorite running influencer as well. They might show you great new tech, or provide inspiration but when it comes to structuring your training, get guidance from a certified coach who can build a plan around your actual goals and injury history.
🥇 Gold: Ignoring Strength Training
Gold goes to a mistake I see even high-level runners commit; skipping the weight room entirely. There's a common myth that strength training will make you "bulky,” slow, or deminish your training. In reality, runners who neglect strength work are far more likely to develop weaknesses in the hips, glutes, and core. Those exact muscles responsible for keeping your stride efficient and your joints protected over hundreds of thousands of repetitive strides.
What to do instead: Two short strength sessions a week, even just 20-30 minutes, focused on single-leg stability, hip strength, and core control, will do more for your running longevity than almost any other habit you can build. Squats, step-ups, glute bridges, and planks are a great starting point.
The Bottom Line
None of these mistakes come from laziness, they come from enthusiasm. The fix isn't to want it less; it's to train smarter. Nail these three fundamentals, and you'll be running stronger, longer, and injury-free.
About the Author
Josh Kober is the co-owner and head coach at Glide Training Co., a boutique personal training and run coaching studio in Bankers Hill, San Diego. He holds a degree in Exercise Science, an ACSM Personal Training Certification, and an RRCA Running Coach Certification, with 15 years of experience coaching runners from first-5K beginners to Boston Qualifier hopefuls. Josh also leads the Maple Canyon Run Club and writes regularly on running form, injury prevention, and training strategy at glidetc.com/blog.
Have a running question of your own? Reach out at Glide Training Co., 2056 1st Ave, San Diego, CA, or join us for the Sunday Social Run at Communal Coffee in Bankers Hill.