Coaches Warn New Runners Add Speedwork Too Soon
Running coaches and a physical therapist outline clear physiological and consistency benchmarks runners must meet before safely introducing speed or hill
New runners often risk injury by adding high-intensity speedwork before building a proper aerobic base, according to running coach Greg Laraia and physical therapist Anh Bui. Bui, a DPT and level 1 USATF-certified coach with Run Resiliently Physical Therapy, compares the mistake to a novice lifter attempting a one-rep maximum on their first day.
Building a base through easy runs allows critical physiological adaptations. Muscles, tendons, and bones acclimate to impact. Blood and oxygen flow improves. Mitochondria, the cell's energy powerhouses, develop. "You can do a lot with just easy running," Bui emphasizes. Once that foundation is solid, adding intensity under proper guidance can boost speed over distance, improve form, and teach pace management.
The challenge is determining when a runner is ready. Impatience is common, Laraia says, but paying attention to key readiness signals pays off in long-term health and progress.
Readiness Checklist for Adding Intensity
Coaches Bui and Laraia advise runners to meet several benchmarks before introducing speedwork. Genetics and running history play a role, but specific indicators provide a roadmap.
You Built Volume. A rough weekly mileage benchmark exists, though it varies. Bui suggests runners should generally be handling 15 to 20 miles per week. "I think in general, people can do a lot with 15 to 20 miles a week," she says.
You Know What Easy Means. This is more critical than a specific mileage number. Base miles must be run at a truly easy, conversational pace. Laraia warns that running 15 miles in heart rate zone 4 means the intensity is already too high. Easy runs should be in zone 2, verifiable via the talk test or heart rate data. Consistency over four to six weeks with a lowering heart rate indicates proper adaptation.
You Run Consistently. Frequency and regularity trump a single high-mileage week. Laraia includes consistency on a checklist, ideally running a minimum of three times weekly for about six weeks. "If you're consistent over time, you will get better," he notes.
You're Recovering Well. Runners must feel well-recovered from their current load. Energy levels should be good daily, and any soreness should not linger beyond 48 hours post-run. Laraia adds that adequate sleep and managed life stress are vital, as intensity is another stressor.
You're Not Injured All the Time. A runner should not be currently injured. Bui notes those with a history of injuries like stress fractures or RED-S may need a prolonged period of easy running to prove they can handle the mileage before stacking on intensity.
How to Introduce Intensity Safely
If all boxes are checked, runners can ease into intensity. Bui cautions to change only one variable at a time-do not add both more miles and intensity simultaneously.
Start With Strides. Both experts recommend beginning with strides. These are four to eight reps of 15- to 30-second pickups at about 80 percent effort, done within or at the end of an easy run. They require no specific pace. Laraia likes placing them in the last two miles. Uphill strides at the same effort also help mechanics. "Hills teach you how to pump your arms, how to drive your knees, how to push off your toes," Laraia says.
Try Fartleks. Bui loves fartleks for beginners as a way to explore different paces without knowing threshold paces. It involves DIY intervals of fast running mixed with jogging recovery. "You're just playing around with different speeds," she says.
Measure Your Intensity. Use the talk test or rate of perceived exertion (RPE). During intensity, you should still be able to say a couple of words, correlating to a threshold effort. Using RPE, aim for 7 to 9 out of 10 based on effort length. Heart-rate data can be incorporated later.
Follow the 80/20 Rule. The principle states 80 percent of running should be easy, 20 percent intense. Beginners often skew toward 50 percent intensity. "Applying or starting to think about the ratio... Is important," Bui says.
Listen to Your Body. Shin splints, worsening aches during a run, and soreness lasting more than two days are clear signs to pull back. "Be very mindful of how you feel the day after incorporating intensity," Bui adds.
