The virtual half marathon: a first-timer’s guide

• The exact distance. A standard half is 13.1 miles. Some events round it. THOR counts 21 km, about 13 miles.
• Whether it must be one run. If you want to split the distance over days, check that the event counts it.
• Whether the window suits your training. Dated events fix the weeks. Others start when you do.
• When the medal arrives: at sign-up, or only once your distance is recorded.

For a single 13.1-mile run, most beginner plans run 12 to 16 weeks. That gives you time to raise your weekly distance slowly, which is what keeps first-timers healthy. If you can already run a 10K comfortably, 12 weeks is realistic. If 5K is still hard, start with the 10K guide and add the half afterward.

A good starting point is three runs a week and a long run of about 4 to 5 miles. If you are below that, add four to six weeks of easy running first.

If you have a health condition, are pregnant, or have not exercised in a long time, check with a doctor before you start.

Three or four runs a week. The weekday runs stay short and easy, 2 to 4 miles each. The long run carries the plan. Every few weeks the long run drops back so your body can absorb the work.

Some of those jumps are a mile. If a week feels hard, repeat it. Adding two weeks to the plan costs nothing. An injury in week nine costs the whole thing.

• One long run a week, at an easy pace. Slower than feels necessary.
• Your longest run usually comes about two weeks before the day. For a first half, 10 to 11 miles is plenty. You do not need to run 13.1 in training.
• Practice what you will do on the day: the same shoes, the same breakfast, the same drink or gel.
• Walk breaks are fine. Plenty of first halves are run-walked, and a planned 1-minute walk every mile can keep your pace steadier.

How slow is easy? See how fast your long run should be. The short version: you should be able to talk in full sentences.

Endurance athletes in many sports do most of their training at low intensity and a smaller share hard. A first half marathon does not need hard sessions at all. If you want one, add it after week four: a 20-minute “comfortably hard” tempo run in the middle of a weekday run, or the strides and minute pickups in the interval training guide. Keep it at least two days away from your long run.

Two short strength sessions a week help as well. The strength training guide for runners has a 20-minute routine you can do at home.

Once your long runs pass about 75 minutes, practice drinking and taking carbohydrate on the move. A handheld bottle and a gel or two are enough. Try them on long runs first, never for the first time on the day. The guides to energy gels and how much water to drink go into amounts.

A taper cuts your running before the day so you start fresh. A 2007 review of tapering studies in competitive athletes found the best results came from a taper of about two weeks, cutting training volume by roughly 41 to 60%, while keeping intensity and how often you train about the same.

Do not try to make up missed runs in the last two weeks. The fitness is already built.

Without a race course you build your own day. That is a big part of the fun.

• Choose loops. Three loops of about 4.4 miles, or a longer loop that passes your home or car, give you a place to refill water and grab a gel.
• Set up an aid station. A cooler on the porch or in the trunk with water, a sports drink and a snack works like a race table.
• Start early in summer. Heat slows everyone down, and the running in the heat guide explains how much.
• Bring a friend for part of it. Someone on a bike, or a running buddy for the last few miles, makes a long way feel shorter.
• Check the route is safe and lit if you start before sunrise.

Because THOR counts every session inside its window, it suits two very different runners:

• The one training for a single half. Record the long run on the day and the medal is the finish line.
• The one who is not there yet. About 1.1 km a day, or three 7 km (4.3-mile) sessions, covers it with no single long run at all.

THOR closes the Legends Of Asgard set after LOKI and ODIN. See the THOR challenge. Prefer to walk it? Read how to walk a virtual half marathon.

• How long does a first half marathon take? Many first-timers finish in 2 hours 15 minutes to 3 hours. Run-walkers often take longer, and that is fine.
• Do I need to run 13.1 miles in training? No. A longest run of 10 to 11 miles is enough for most first halves.
• Can I train in eight weeks? If you already run 6 miles comfortably, possibly. From a 5K base, 12 to 16 weeks is safer.
• What if I miss a week? Pick up where you left off, or repeat the last week you completed. Do not double up.

• Bosquet L. et al. Effects of tapering on performance: a meta-analysis. Med Sci Sports Exerc, 2007
• Seiler S. What is best practice for training intensity and duration distribution in endurance athletes? Int J Sports Physiol Perform, 2010
• How to Measure Physical Activity Intensity, CDC