Sub-18 Minute 5K — Training Paces and Fitness Profile

Sub-18 is where serious competitive running begins. At most local road races, this places you in or near the top finishers. The training paces required reflect genuine sub-elite fitness — not recreational-level training with occasional speed work.

Quick answer: To break Sub-18:00 in the 5K (RPI 56.4), your training paces are: easy 7:46/mi, threshold 6:19/mi, interval 5:34/mi. Equivalent fitness: Marathon 2:52:11, Half Marathon 1:22:27.

Training paces for Sub-18:00 5K

RPI 56.4 · Goal: 17:59 · All paces in min/mile

Easy (80%+ of weekly running)
7:46/mi4:50/km
Marathon Pace
6:41/mi4:09/km
Threshold (comfortably hard)
6:19/mi3:56/km
Interval (VO2max sessions)
5:34/mi3:28/km
Repetition (short fast reps)
5:11/mi3:13/km

Calculated from Daniels/Gilbert oxygen cost equations. Easy pace means "this pace or slower."

Equivalent race fitness

These are the predicted equivalent times at other distances for a runner with RPI 56.4 — assuming comparable training for each distance.

Marathon

2:52:11

6:34/mi

Half Marathon

1:22:27

6:17/mi

10K

37:17

6:00/mi

Training approach for Sub-18:00 5K

Sub-18 5K requires a well-developed VO2max and real threshold stamina. The aerobic ceiling needs to be high enough that 5K race pace — near-maximum aerobic output — is sustainable for 17–18 minutes. Interval training (800m–1200m repeats) raises this ceiling. Threshold training (tempo runs at threshold pace) builds the metabolic stamina to sustain high-intensity output without rapid lactate accumulation. 50–70 miles per week is a typical range for runners at this level.

Calculate your current training paces

The table above shows paces for Sub-18:00 5K fitness. Enter your current race time to see where you are now and how far from the goal you sit.

Training Pace Calculator

These paces are based on your race time — not your body

The Daniels/Gilbert formula predicts training zones from a single race result. StrideIQ goes further: it tracks how your body specifically responds to threshold and interval work — which sessions produce your biggest gains, how quickly you recover, and when your fitness is peaking. Population formulas start the conversation. Your individual response data finishes it.

Training pace tables →Start free trial

Common questions

What training paces does a sub-18 minute 5K require?

For sub-18:00 (17:59), your zones are: Easy 7:46/mi, Marathon 6:41/mi, Threshold 6:19/mi, Interval 5:34/mi, Repetition 5:11/mi. RPI 56.4. Easy pace (7:46/mi) should feel comfortable for hours — most runners at this level run their easy days 90–120 seconds per mile slower than race pace.

Is sub-18 achievable for adult runners who took up running in their 30s?

Yes, for adults who start running in their 30s and train consistently for several years. Sub-18 requires a VO2max in the upper range of recreational fitness, which develops with sustained training. Time-to-standard is typically 3–5 years of consistent mileage with structured quality work. Genetics (VO2max ceiling) does matter — some runners will reach this level and some will not — but most who fail to get there fall short on training consistency, not genetic ceiling.

What equivalent marathon fitness does sub-18 5K represent?

Sub-18 5K fitness (RPI 56.4) projects to approximately 2:52:11 marathon potential. Converting this aerobic capacity to marathon performance requires distance-specific training: 20-mile long runs, marathon-pace work, and sustained high-volume build. Without it, most sub-18 5K runners significantly underperform their marathon equivalent.

Other goal pace guides

Sub-20 Minute 5K →Sub-25 Minute 5K →Sub-40 Minute 10K →Sub-50 Minute 10K →Sub-2 Hour Half Marathon →Sub-4 Hour Marathon →Sub-17 Minute 5K →Sub-19 Minute 5K →Sub-21 Minute 5K →Sub-22 Minute 5K →Sub-23 Minute 5K →Sub-24 Minute 5K →Sub-27 Minute 5K →Sub-30 Minute 5K →Sub-35 Minute 10K →Sub-36 Minute 10K →Sub-37 Minute 10K →Sub-38 Minute 10K →Sub-39 Minute 10K →Sub-42 Minute 10K →Sub-45 Minute 10K →Sub-48 Minute 10K →Sub-55 Minute 10K →Sub-60 Minute 10K →Sub-1:15 Half Marathon →Sub-1:20 Half Marathon →Sub-1:25 Half Marathon →Sub-1:30 Half Marathon →Sub-1:35 Half Marathon →Sub-1:40 Half Marathon →Sub-1:45 Half Marathon →Sub-1:50 Half Marathon →Sub-2:30 Marathon →Sub-2:45 Marathon →Sub-3 Hour Marathon →Sub-3:05 Marathon →Sub-3:10 Marathon →Sub-3:15 Marathon →Sub-3:20 Marathon →Sub-3:30 Marathon →Sub-3:45 Marathon →Sub-4:30 Marathon →Sub-5 Hour Marathon →Training Pace Calculator →

Paces calculated using the Daniels/Gilbert oxygen cost equations (1979). All values derived from the same formula used by the StrideIQ training pace calculator. Goal times use the target-minus-one-second convention (e.g., sub-20 = 19:59 input).