Hiking Vs. Running

When to hike vs. when to run?

My good friend and co-coach Jackson Brill published a study recently focusing on when to run versus hiking at steep grades and what accounts for this decision. The study can be found here, but I’ll do my best to give the summarized version below. All research papers start off by stating what makes their study different and why it’s important. There has already been research done addressing the question of walking versus running on a flat surface, and the speed where the transition between the two makes sense. It seems that people like to switch from walking to running at around 2 meters/second (roughly 4.5 miles per hour, or roughly a 13.5 min/mile). 

The reason for this switch between running and walking on flat ground isn’t as obvious as it would seem. I would assume that body knows what is more economical (i.e. more energetically efficient) and try to keep you in a movement pattern that is more efficient. However, it seems that around 4.5 miles per hour, the tibialis anterior muscle (which controls dorsiflexion or pointing your toes towards your shin) is considered the ‘trigger muscle’ that may have more of a say in when you prefer to transition between the walking and running gait. 

This is an interesting thought in that your body is willing to utilize more energy in order to save the tibialis anterior from fatiguing. The tib anterior is a small muscle, but is very important in walking as it keeps your toes from slapping the ground as it eccentrically contracts (under load while lengthening). Since it is such a small muscle, it is more susceptible to fatigue and has less energy on board, so switching to a running gait and utilizing more of your gastrocnemius (calf muscle) and other primary running drivers that have a higher energetic cost seems better! 

Now… back to the main purpose of Jackson’s study; to find when the body prefers to switch between walking and running gaits at steep inclines. We have all faced this dilemma during a run. You approach a steep climb that feels runnable, but you’re unsure whether or not it makes more sense to run it, or hike it. The run going up it may feel miserably slow, and you’re pretty sure that hiking it will be the same speed. What should you do? 

To test this question, Jackson and his colleagues recruited 10 ‘fast’, male trail runners in the Boulder, CO area. As with all exercise physiology studies, the sample size and type are both huge limitations of the study. They tested the subjects on a 30° incline at a speed of 1 meter/second (roughly 2.25 mph) and measured what muscles were excited/engaged depending on walking versus running. They chose the speed of 1 m/s at 30° incline as winning speeds during VK (vertical-kilometer) events averages around 1.1 m/s where participants often switch between running and walking. 

A separate study found that walking/hiking up a grade of 30° at .9 m/s is more economical (energetically efficient) than running at the same grade. The ‘crossover point’ (point where running and walking become equally energetically efficient) occurs somewhere between 1.0-1.2 m/s and deciding between a walking and running gait in this speed range occurs for a reason independent of metabolic cost. 

Jackson and colleagues deduced that similar to the transition point of walking versus running on level ground, the transition occurs because of muscle fatigue on steep pitches as well. Whereas the tibialis anterior dictates the transition during flat running, the fatigue of the soleus muscle (one of your main calf muscles controlling plantar flexion) seems to be a determining factor in the transition at steep grades.

More simply put, hiking up a steep hill fatigues your soleus muscle (part of your posterior calf grouping responsible for plantar flexion/toe-off) more than running, and to alleviate this fatigue, you may start running to provide that muscular relief and activate different muscle groupings. 

This is all pretty ‘in the weeds’, but interesting none-the-less. It’s often best to listen to your body as it generally chooses its preferred gait for useful reasons that we may not be entirely aware of. Granted, a fun takeaway from this is that switching between running and walking at steep grades may be a great way to save energy and muscle damage during the course of a long, mountainous run! 

A quick tangent that seems relevant to the discussion above is whether or not to use poles. As a coach, I suggest that if you plan on using poles, you should absolutely practice with them in training. However, when does it make sense to use them? Pole usage is less metabolically efficient than not using them, but the loss of economy becomes less at steeper and steeper climbing grades. Additionally, pole usage reduces muscle damage and fatigue that may be of assistance later in a long race. Once again, this is personal preference, but during races with steep climbs and long duration, pole usage makes a lot of sense! 

Gear Review: 

This week, I’m actually going to go into a few considerations for choosing a running pack! 

There are a million options out there, and most of them are high quality. The ‘ultra-running’ technology keeps improving and it’s hard to know what will work best for you! 

1- Storage size: If you’re using this for a few hours on the weekend, you don’t need a lot of storage capacity and having it will feel clunky. Packs sit best when full of gear, so choose a size that fits your needs.

2- Bladder vs. soft-flasks: I generally like soft-flasks because they’re easy to refill and faster in a race environment. However, if you are going a long way without a water refill, a bladder is a better option with increased storage capacity. It also tends to sit better in the back and doesn't bounce around like soft flasks do up front.

3- Fitting size: As mentioned above, a pack fits better when it’s full. Try to test a pack before buying it. Fill it with ‘gear’ and run around the store. Does it bounce with your stride? Does it feel constricting to your upper torso? Does anything bounce? Anything that is even the tiniest bit annoying when testing will be VERY annoying on a long run. Comfort is the most important aspect. 

4- ‘The bells and whistles’: Light packs are generally better. They breathe well and saving weight gives you better energy return on a long run. Where are the storage units? Will you be able to access the gear you need easily? I like to have ‘emergency supplies’ in the back of the pack and anything that I may use during the run in the front. Taking a pack off takes time, and if you’re in a race environment, this matters!