Half-Marathon Training Guide

Whether you have questions about how much to run, how to recover, or what pace to run your race at, you've come to the right place. To make your training even easier, our expert coaches have designed free half-marathon training plans available at the bottom of this guide.

Improving Your Approach

Unlike the 5k or 10k distance, preparing for a half marathon requires a longer training period which builds in distance as you go. With the right approach, however, any athlete can build the fitness and confidence needed to achieve their goals.

Frequency

On average, half-marathon runners should target 4-6 runs/week. This can change based on ability, but the first phase of improving your fitness is to increase your frequency.

Coaching Tip: As you increase frequency, aim to keep your overall mileage similar. Adding running days to your schedule introduces stress as well. So if you previously ran 3 days a week at 5 miles each, try increasing to 5 days/week at 3 miles first.

Volume

Once your frequency has improved, the next phase is adding more volume. One simple rule: Increase mileage by 10% per week, and keep your long run under 30% of total weekly volume to reduce injury risk. Start with where you are, work backward from race day, and give yourself 8-16 weeks to build. If you’re running 15 miles per week now, aim for 16.5 next week, with a long run no more than 5 miles. Small, incremental progress adds up to big race-day results.

COROS Education: The Training Status metric is an easy tool to monitor if you are training the right amount. It compares your short-term stress to your long-term fitness to ensure you progress your training at the right rate. Athletes should aim to keep their Training Status in the "Optimized" category while building their volume.

Tracking Your Progress

Every run you perform impacts your progress, but not all runs are created equal. Some place higher stress on your body than others, and tracking that stress is the key to unlocking progress. Once you can measure it, you can improve it.

Within the COROS App, you have access to a trendline called "Base Fitness". The higher the score, the more stress your body can handle. During your half-marathon training, it is important to see improvement so you can ensure your training is working.

An example of the Base Fitness metric increasing over time

COROS Education: Base Fitness is a rolling average of your daily Training Load. With every run you complete, training load measures the stress on your body. When your Base Fitness is improving, and recovery is being monitored, you are taking the appropriate steps to better results.

Monitoring Your Recovery

Training breaks you down—recovery builds you up. Your increased effort needs proper recovery to make you stronger. Ignore it, and you risk injury or stagnation.

A simple approach is to train for 3-4 weeks, then scale back the effort for a recovery week. However, with COROS recovery metrics, you don’t have to guess. Tracking these metrics will help you know when to push and when to rest—so you can train smarter and avoid unnecessary downtime.

COROS Education: Heart Rate Variability (HRV) and Resting Heart Rate (RHR) are key indicators of recovery. A declining HRV or an increasing RHR can signal that your body needs more rest. Read more on all of our recovery metrics

Planning Your Race Pace

The surge of adrenaline at the start line makes it easy to begin too fast. However, smart pacing ensures you finish strong. Relying on feel can be difficult, so COROS has developed features to stay locked into your goal pace.

COROS Race Predictor:
Your watch learns from every run, refining your predicted finishing times as you train. The more you improve, the faster your half-marathon projection becomes.

COROS Virtual Pacer:
On race day, set yourself up for success. Before hitting start, scroll to “Pacer,” select “HM,” and enter your goal time. Your watch will then provide real-time pace alerts, keeping you steady from the first mile to the last—helping you avoid early mistakes and maximize your potential.

COROS Training Plans to Help

While the tips above can help runners make the most of their training, we realize this takes time to plan and execute. To better help athletes of all abilities, COROS has created a handful of half-marathon training plans that are free to use.

Once you've found the right plan for you, sync it to your COROS watch for a step-by-step guide on every run along the way.

Beginner Training Plans

12-Week Beginner Half-Marathon Training Plan - Pace

12-Week Beginner Half-Marathon Training Plan - Heart Rate

Intermediate Training Plans

12-Week Intermediate Half-Marathon Training Plan- Pace

12-Week Intermediate Half-Marathon Training Plan- Heart Rate

Advanced Training Plans

12-Week Advanced Half-Marathon Training Plan- Pace

12-Week Advanced Half-Marathon Training Plan- Heart Rate

Plans Based on Goal Time

Sub-2:00 Half-Marathon Training Plan

Ready to Train? Get the Right Gear

To make the most of your half-marathon training, equip yourself with the right tools. The COROS PACE series provides accurate tracking and advanced training metrics, while accessories like the COROS Heart Rate Monitor and COROS POD 2 offer precision and accuracy for all of your running needs. Check out the COROS products page to find the perfect gear for your training journey.