Adaptive · New

A Half Marathon plan that ends
on your race day

Set your race date. We generate a plan of 10 to 24 weeks that ends exactly on race day — with the last week tapered. No gaps. No improvising.

10-24

Adaptive weeks

4×

Sessions / week

Ends on race day

Download the app free

Pick your race date inside the app

Who this plan is for

Solid running base: you currently run 4 days a week and have done a 10K
You want to finish strong or PR: first 21K or improve your time
4 running days per week: with one long run on weekends
Time for long runs: 90+ min easy runs in the last weeks

What the plan includes

Phase	Weeks	Content
Base	1-4	Easy mileage progression. Build aerobic base. Long runs 10-14 km.
Build	5-8	Intervals and tempo. VO2max and threshold development. Long runs to 16 km.
Specific	9-13	Race-pace blocks within long runs. Long runs to 18-20 km.
Peak	14-15	Highest training load. Sharpening sessions at race pace.
Taper	16 (last)	Volume reduction 50% in last week. Short activations. Fresh legs.

Sample week (week 10)

MondayRest

Tuesday50 min easy + 8x100m strides

WednesdayRest or strength/core

Thursday4x2 km at half-marathon pace (90s jog recovery)

FridayRest

Saturday40 min easy run

Sunday18 km long run with 6 km at HM pace

Why train with CorrerJuntos

📡

Real-time GPS & metrics

Track splits, pace and distance for every interval session and long run.

🤝

Runner community

Find training partners for intervals and shared race goals.

Group runs near you

Join training meetups and Half Marathon (21K) runs happening in your city.

🎁

100% free

GPS, training plans, community. All free.

Frequently asked questions

How much can I improve my Half Marathon (21K) time?

With a structured plan, most runners improve their Half Marathon (21K) time meaningfully. The exact gain depends on your starting fitness, consistency, and adherence to the plan.

How does the adaptive duration work?

You set your race date and the plan generates between 6 and 18 weeks of training, ending exactly on race day with the last week tapered. If your race is too close (under 10 weeks for a Half Marathon (21K)), the app suggests a shorter distance instead.

How many days per week?

The plan is built around 4 running days per week, with optional strength or cross-training. Rest days are essential for recovery and adaptation.

Can I combine this with strength training?

Yes, and we recommend it. Add 1-2 strength sessions per week, ideally after an easy run or on rest days. Focus on legs and core. Avoid lifting before quality sessions.

Where do I access the plan?

The plan lives inside the CorrerJuntos app. Download it free on App Store or Google Play, create your profile and go to Training Plans to activate the Half Marathon (21K) plan.

Start your free plan

Train smart for your Half Marathon (21K) with an adaptive plan that ends on your race day. Thousands of runners already train with CorrerJuntos.