The short answer: lactate threshold pace, not VO2 max, is the strongest single predictor of your marathon finish time. Research on elite and recreational runners consistently shows LT pace outperforms VO2 max as a race-time predictor, from Joyner and Coyle’s landmark physiology of champions review to a 2026 analysis of 888 athletes from recreational to world class showing speed at lactate threshold serves as the working proxy for endurance performance. But before any of that speed work matters, your base mileage has to be there first. This guide covers both, and the workouts that actually move the needle.
Table of Contents
Each is unpacked in the sections below:
Nearly every runner who comes to us stuck at the same finish time was following a generic plan, a cookie-cutter schedule, or workouts that were never adjusted as their fitness improved. The pattern shows up almost every time we review a new runner’s training history.
Once the paces are recalculated and the plan starts adjusting as fitness improves, training Hard, Smart, and Consistent, the plateau usually breaks. Not from adding a new workout type. From fixing the programming.
Every speed workout has to be Hard enough to create adaptation, Smart enough to match your actual current fitness, and Consistent enough to keep adjusting as that fitness improves. Runners who chase one workout type in isolation, or run every session at the same guessed effort, plateau or get hurt.
Smart is where most runners fall short. Running “by effort” without a real number behind it usually means running too hard on days meant to be moderate, and not hard enough on days meant to push adaptation.
A recent time trial or race result, adjusted for how well it was executed. A finish time by itself isn’t a clean read on fitness.
This is exactly why we rarely assign race pace as a training pace. Race pace is a goal. Training paces should come from where you actually are.
A sustained effort at a pace calculated from your current fitness, not a fixed number pulled from a chart. Generic guidance says tempo should feel comfortably hard, a 7 or 8 out of 10, but that description is exactly the kind of vague label that leads runners astray.
Standard tempo protocol:
The specific pace matters more than the general feeling. Two runners can both describe a tempo run as “comfortably hard” while one is training productively and the other is running too fast for their fitness.
Once you have a real aerobic base, worked in alongside tempo training at a pace matched to your current fitness. How much VO2 max work versus tempo work you need depends on your training history and how you’re responding, which is exactly why a generic split doesn’t work as well as a plan monitored and adjusted for the individual. Full protocol here: Benefits of VO2 Max Workouts.
Short, relaxed accelerations, usually 15 to 20 seconds, that improve running form without adding real fatigue. They’re not a workout in the traditional sense. They’re a tune-up.
One tempo, one interval or fartlek session, everything else easy, all at paces calculated for your current fitness. A typical week looks like this:
Most runners run their easy days too fast, and since easy running makes up the majority of weekly volume, getting that pace wrong undermines the entire week. The goal on easy days isn’t just slower, it’s landing in the specific range where aerobic fitness actually improves.
Running every workout at a guessed effort instead of a calculated pace. Runners routinely turn tempo runs into races, and easy runs into moderate ones, because they’re going by feel instead of a number tied to their actual fitness.
A slower, correctly calculated pace, done consistently, beats a faster guessed pace done occasionally and followed by days of unplanned recovery.
Race day pacing should come from your current fitness, shown by recent time trials, not an aspirational goal time. Great fitness executed with the wrong pacing strategy still produces a result that looks worse than the runner actually is.
That’s the same Smart principle applied on race day: run the pace your current fitness supports, not the pace you’re hoping for.
Flat terrain removes one entire variable from calculating pace. No hills to distort a split, no elevation to make a pace look faster or slower than the effort it actually represents.
Group tempo sessions along the St. Pete waterfront still come back to individual pacing, since even in a group setting, each runner’s assigned pace is calculated from their own current fitness, not the pack’s. That’s the structure behind the St. Pete Run Club.
How do I know what pace to run my tempo runs at?
It should be calculated from your current fitness, typically from a recent time trial or race adjusted for pacing and fueling errors, not a generic effort description.
Why don’t I train at my race pace goal?
Training is meant to build fitness, not rehearse a hoped-for number. Workouts should be run at paces set by your current fitness, and race pace should be the result of that fitness, not the target during training.
Can I improve my speed without a track?
Yes. Roads work well for tempo and interval training as long as the pace is calculated correctly, a track just makes distance measurement more precise.
How long until speed work shows results?
Most runners see measurable improvement within 6 to 12 weeks of consistent training, though the timeline depends on starting fitness and how precisely the plan is matched to it.