How Long Does A 100 Mile Run Take?

My first 100 mile run took me about 25 hours to complete. The second one took 34 hours to complete! Both were done completely on trails in the mountains of Oregon. The main difference between the two being just how mountainous the courses were.

So, how long does a 100 mile run take? A 100 mile run can take just 12 hours for the most elite runners and as long as 48 hours for the back of the pack racers. There are so many factors that can vary finishing times. Things like trail vs road, flat vs hilly and the conditioning of the person running. You can sign up to run 100 miles on a track or do a race around Mount Blanc in the Alps with over 30,000 feet of vertical gain.

Keep reading below and we’ll dive into some exciting facts about running 100 mile races. Like which runner accomplished the fastest time in the world as well as if there’s hope for an average joe runner to complete the distance. Let’s dig in!

Average Finishing Times for a 100 Mile Race

Ultrarunning magazine published an article in 2015 with the average finishing times of men and women for the 100-mile race in 2014. Men completed at a time of 28.08.04 and women finished around 28.34.01. (data)

The American record for the fastest finish is held by Zach Bitter. A 27 year-old teacher from Madison, Wisconsin who ran the ultramarathon in less than 12 hours! An amazing feat, to say the least.

Zach Bitter Ran 100 Miles in Less Than 12 Hours

On November 10, 2018 a young man named Zach Bitter broke the 100-mile race record (on trail) at the Tunnel Hill race in Vienna, Illinois. He completed in a time of 12:08:36, just 28 minutes shy of his previously held record (on a track) of 11:40:55 in 2015 at the Desert Solstice race in Phoenix, Arizona. His average pace was 7:14 per mile.

His time was 24 minutes faster than the previous 100-mile record set by Jonas Buud at the Taby Extreme Challenge in Sweden back in 2010. He owed his record win to his conscious mental focus and a great ipod playlist, including hits from AC/DC, Beastie Boys and Eric Church. A
true inspiration for any runner contemplating a 100 mile ultramarathon of their own.

How to Prepare for your First 100-Miler

Preparing for the ultramarathon is key. You need to lay the groundwork first, regardless of your experience or fitness level. Let’s take a look at these necessary preparations below.

Eat plenty the night before. Eat a large dinner the evening before the big race. Be sure to include foods rich in complex carbohydrates, protein and some fats. A good example would be a large helping of brown rice with vegetables and chicken or salmon. The idea is to ‘carb load’ so your muscles are filled with glycogen which provides the energy needed for intense physical activity.

Eat again three hours before. A few hours prior to race time, begin loading up on calories and drinking electrolyte water. Slow release carbohydrates are the best forms of nourishment, such as oatmeal topped with fresh fruit or a bagel with peanut butter. These digest slowly and keep blood sugar levels stable, both of which is necessary for muscle endurance.

Know the course beforehand. Always be aware of the terrain in which the 100-miler is run. That way, you can better pace yourself, running faster on flat land surfaces and slower on the inclined areas, for example. Knowing what lies ahead is an important part of the challenge that awaits along the trail.

Do not do the entire distance in advance during training. To avoid injury and muscle burn-out, it is not recommended to run the entire distance at once prior to the race. Try doing three to six 20-mile runs instead or a 50-mile run six to twelve weeks before the 100-miler.

Pack the necessary provisions. Be sure you have adequate food and water to complete the race. If you plan to run longer than 90 minutes, you need to be prepared to replenish your calories along the way. Sports drinks and energy bars are a typical choice.

How to Pace for your First 100-Miler

Pacing yourself throughout the race is vital to completion. You need to set realistic goals based on your current fitness level and skill set. Let’s review some possible pacing options below.

Don’t start too fast. It is easy to get caught up in the excitement of the race. However, fast starts can often result in slow finishes. Meaning that you will ‘hit your wall’ earlier on, using the majority of your energy at the beginning with little left to withstand the remaining distance. Resist the adrenaline rush, control your pace off the get-go.
Use a pacer. A pacer is an experienced runner who helps you achieve a certain speed goal for your race or to simply help you get to the finish. A pacer can help motivate you during the low points of a race that are sure to come. It helps to find pacers you are already familiar with as they will be spending many many hours with you out on the trail.

In many 100 mile races a pacer is not allowed to join the runner until halfway through at the 50-mile marker. It is the pacers job to match your desired speed rate, keep you on the trail, make sure you eat and drink along the way, assist you in replenishing your food and water provisions and encourage you as you go!

Consider a ‘hike the hills’ strategy. A very popular way to conserve energy during a 100 mile race is to hike the hills and run the flats/downhills. It is very easy to overdo early stages of a race by running up inclines just because you feel good. But more than likely, you’ll be pushing your heart rate too high and will pay for it later.
It’s ok to walk. Just because you are participating in a “running” event doesn’t mean you have to run the entire way! Walking periodically, especially before the legs become fatigued, is a good thing. It shifts energy to those untapped leg muscles which keeps you feeling stronger, longer. It is recommended to start these walk breaks early in the race, even if you feel you don’t need to.
Address discomfort immediately. If a blister should develop or your sock needs adjusting, take care of it right away. As quickly as possible, slap a bandage on that blister or change that sock and then continue on your way. Don’t wait until the pain or irritation is so intense that you can barely stand it!

Minor injuries are often a sign of the body ‘pushing the limits’ of your running ability. Listen to your body. Recognize your true limitations and modify the run to avoid a more serious injury down the road.

Almost Any Runner Can Finish a 100-Miler

Any reasonably healthy individual (regardless of age) can complete a 100-miler. If you love the outdoors, enjoy being active and are willing to train hard, you too can compete in an ultramarathon. Knowing your own limitations and fitness level is crucial. Often the determining factor is not a physical one but rather a mental one. Thinking of the extreme distance and the challenges that lie ahead can ‘psyche out’ a person before he/she even starts.

There is a natural progression to everything. If you have only ran as far as a marathon, consider jumping to a 50k, then a 50 miler and so on until you reach the 100 mile race distance. Take your time and enjoy the journey.