Sub-1:50 Half Marathon — Training Paces and Fitness Profile
Sub-1:50 half marathon is a meaningful step toward competitive recreational fitness. It sits between the recreational milestone of sub-2:00 and the structured training level of sub-1:45 — and getting there typically requires adding real quality work to an easy-run base.
Quick answer: To break Sub-1:50:00 in the Half Marathon (RPI 40.4), your training paces are: easy 9:50/mi, threshold 7:44/mi, interval 6:46/mi. Equivalent fitness: Marathon 3:47:43, 10K 49:35.
Training paces for Sub-1:50:00 Half Marathon
RPI 40.4 · Goal: 1:49:59 · All paces in min/mile
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 40.4 — assuming comparable training for each distance.
Marathon
3:47:43
8:41/mi
10K
49:35
7:59/mi
5K
23:54
7:42/mi
Training approach for Sub-1:50:00 Half Marathon
For sub-1:50 half marathon, the primary additions to a recreational base are threshold training and extended long runs. One threshold session per week (12–18 minutes at threshold pace) and long runs building to 11–13 miles produce the adaptations this level requires. Easy volume of 25–35 miles per week with strictly easy recovery days allows these quality sessions to generate adaptation.
Calculate your current training paces
The table above shows paces for Sub-1:50:00 Half Marathon 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.
Common questions
What training paces should I use to target sub-1:50 half marathon?
For sub-1:50:00 (1:49:59): Easy 9:50/mi, Threshold 7:44/mi. RPI 40.4. Easy pace (9:50/mi) is where the majority of your training volume lives. Threshold at 7:44/mi for 12–18 minutes once per week builds the specific metabolic capacity sub-1:50 requires.
What is the typical progression from 2:00 to sub-1:50?
Runners who have broken 2:00 in the half typically reach sub-1:50 in 4–8 months of structured training. The key transitions: running easy days more strictly easy (often requires slowing down significantly), adding a threshold session each week, and building the long run to 11–13 miles consistently. This combination produces steady improvement.
What marathon does sub-1:50 half fitness predict?
Sub-1:50 half marathon fitness (RPI 40.4) projects to approximately 3:47:43 marathon potential. If the marathon is your next goal, this fitness level puts you in range for the predicted time — with full marathon-specific preparation (20-mile long runs, marathon-pace work).
Other goal pace guides
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).