This past weekend, I was on my 10 mile Sunday long run. It was about 90 degrees outside with no shade for miles.  This run was really difficult and I couldn’t imagine having to run a full marathon (26.2 miles) right now.  As I continued with my long run, I saw a cyclist pass me going at least five times faster than my running pace.  This got me thinking, as an avid runner and bike rider, what would be the biking equivalent to running a marathon?

Marathons are one of the most difficult in challenging races running and in any sport.  In order to run 26.2 miles you must push yourself physically and mentally.  Running and biking are two very different sports, however, they can be related because they challenge your endurance.  I did a little research and found out that the closest biking equivalent to running a marathon is a 100 mile (Century) bike ride.  Let’s take a closer look into how this was determined and what factors should be considered when comparing running and biking.

How Many Miles Biking Equals 1-mile Running?

In order to compare running a marathon to biking, we have to determine how many miles a 1-mile run equals to in biking miles.  It has been determined that running 1 mile is approximately equivalent to biking 3 miles. While this is not a 100% direct correlation, it is our best estimate. An important factor to consider is that in order to properly compare running and biking, the activities must be done with the same effort level. A deeper analysis into how many miles biking equals one mile running can be found in our recent article, How Many Miles Biking Equals One Mile Running?

What Is The Biking Equivalent Of A Marathon?

You might be thinking, by using the rule of thumb that 3 miles biking equals one mile running, we would end up with 26.2 miles running being equivalent to 3 x 26.2 = 78.6 miles biking.  Although this may be true, it is important to consider the extreme toll that running 26.2 miles or Marathon takes on the human body.  The most important aspect to consider is that when running you are constantly impacting your legs whereas when you are biking you are able to move without much impact.  Additionally, there are also some other factors to consider when comparing biking and running that will help our estimation of the biking equivalent to running a marathon.

3 Factors To Consider When Comparing Biking and Running

1. Constant Impact When Running

One of the biggest considerations as stated previously is the constant impact that you experience when running.  Each step when running causes impact to your legs and muscles.  Over the course of 26.2 miles, this can drastically wear down your body and cause bone pain and nasty blisters.  Comparing this to biking, there is relatively no impact for each pedal stroke. When you are biking, you are mainly using your thigh, hamstring, and calf muscles.  However, it is important to recognize that without proper gear you could develop blisters while biking as well.

2. Coasting On A Bike

Another important aspect to consider when comparing running and biking is that when biking, you have the ability to coast on a bike.  Compared to running, you have to constantly be moving if you want to continue moving forward in the race.  Therefore, for our comparison purposes we are stating that it is important to exert the same amount of effort for both sports. By exerting the same amount of energy for both sports, we are able to get a better comparison.  For this comparison it might be more effective to compare running a marathon to biking on a stationary bike.  If you’ve ever biked on a stationary bike you know that the constant pedaling is much more difficult than riding a bike outside.  This constant motion of a stationary bike is more similar to running than biking outside.

3. Faster Rotations/Steps on Bike

When comparing running and biking it is important to consider the faster rotations that are required when biking. It is known that biking requires a faster rotation per minute (RPM). While this RPM can be reduced at times, it is typically higher than running RPM or steps per minute.  This faster rotation can cause additional strain on your muscles and bones. It is very common for these fast rotations to cause knee or hamstring pain.  Therefore, by using the comparison of a stationary bike to running, the more rotations required while biking can make it even more difficult.

Verdict

Running and biking both have their own factors that make them difficult which include constant impact while running and faster movement or pedal strokes when biking.  As long as the same effort level is used for each sport, then the closest biking equivalent to running a marathon (26.2 miles) is approximately a 100 mile (Century) bike ride.  This approximation is slightly more than the 1:3 running to biking miles ratio, because coasting is possible on the bike.  This factor caused a high running to biking mile ratio for the estimation.

As a runner, have you ever been injured or wanted to substitute a running workout with bike workout?  Recently when training for my most recent half marathon training, my legs were tired but I still wanted to maintain my fitness.  I decided on a bike ride as a substitute, however, I wondered how many miles on my bike ride would equal one mile running? After doing research through multiple scientific papers and studies, 1 mile running approximately equals 3 miles cycling at equivalent effort levels.  Let’s look into some things to consider when replacing a running workout with cycling / biking and a comparison table to help you understand your cross-training workout.

Running Miles to Biking Miles Conversion Table 

For your next bike / cycling workout, we have created an easy to follow Running Miles to Biking Miles Conversion Table.

Figure 1. Running Miles to Biking Miles Conversion Table

3 Benefits of Replacing a Run With a Bike Workout

1. Injury Prevention

One of the greatest benefits to doing replacing a run workout with a bike workout is the injury prevention.  Because biking or cycling is a low impact sport as compared to running, it allows your joints and bones to recover from your running training.  During your runs you are constantly impacting your legs and body each time you take a stride. This repetitive impact causes muscles to become fatigued and results in a higher chance of injury.  Replacing one of your run workouts with a bike ride can allow your muscles to recover from this impact.  

2. Improved Fitness

Another great benefit of implementing cycling cross-training into your running training schedule is that it can improve your fitness.  There are multiple factors of bike cross-training that can improve your running. One of these factors is that because cycling is a low-impact sport you can combine your running workout with a cycling workout.  By implementing cycling into your run training schedule you can build muscle and endurance with methods other than running. Although it is similar, cycling actually utilizes muscles differently than running. The motion of pushing and pulling uses highly uses quadriceps and hamstrings.  This will build strength and help improve endurance.

3. Active Recovery

Active recovery is an important component in running training.  Active recovery is when you recover while being active rather than just resting.  This is especially effective when you are feeling fatigued and want to maintain your fitness.  Instead of completely taking the day off of running, you could do a beneficial cycling workout while letting your muscles recover from running impact.  Many studies show that active recovery can actually be more beneficial than static recovery because more blood will flow to your muscles and allow for faster recovery.  Make sure to listen to your body when determining the effort level of your cross-training.

3 Key Differences Between Run and Bike Training

1. Lower Body Workout

There are some differences to consider when substituting a cycling workout for a running workout.  Although running seems like purely a lower body workout, it is actually a whole body workout. When running you are constantly engaging your core, abs, and arms.  Conversely, biking utilizes mainly your lower body and does not build as much arm or core strength. If you plan on doing a bike workout in place of a running workout, it is beneficial to implement some core exercises to maintain your overall fitness.

2. Different Leg Muscles Used

As discussed previously, cycling uses muscles differently than running.  Because of this, you have to be cautious of not replacing too many workouts with cycling workouts because your body may start to build muscles more closely associated with biking.  Additionally, because the muscles used are not identical to running, the running-to-cycling ratio of 1:3 miles is not perfectly correlated. However, these cycling workouts are still beneficial to your running fitness.

3. Outdoor Biking vs Stationary Biking

One consideration that is not commonly addressed is the difference between outdoor biking and stationary biking and how that affects the running-to-cycling ratio.  In outdoor biking, there are many times you are able to use your momentum (without pedaling) to move. Whereas, stationary biking required you to pedal constantly without many breaks.  Comparing this to running, you are not able to move without striding. Therefore, stationary biking is more closely representative of running due to the constant leg motion.  Additionally, the running to cycling 1:3 mile ratio more representative with stationary biking. 

How To Determine The Best Pace for Cross-Training

So, you may be asking yourself what is the best way to determine the pace I should go for cycling cross training.  Because running and cycling paces do not correlate directly, it is more effective to use effort levels. Therefore, if this is a recovery ride you should be pretty comfortable to moderate pace.  Listen to how your body is feeling to determine your effort level. If your legs are tired from the workout in the previous day’s you should take it easy on your cross-training. One thing to keep in mind for cross-training is that you do not want to push yourself too hard.  Cross-training is mainly used for recovery or supplemental training. For beginners you should try to make this area of training the fun part of it. A helpful tip is to find some training partners and do your cross training together. This works especially well because no matter how advanced you are, you are able to train together.  So, for your next cross-training adventure grab a training buddy get a great workout on the stationary bike.

Verdict

One mile running is equivalent to approximately three miles cycling or biking.  As long as you consider the slight differences between the two workouts, the 1:3 running-to-cycling ratio is effective in calculating the equivalent mileage of your next cycling cross-training workout.