Other Adventures

How to Bullet Climb Mt. Fuji... Twice in a day?!?

My friends often say I have an obsession with this mountain. I really shouldn't - it's overcrowded in the summer, an extremely boring climb, and is often enshrouded by view-blocking, hypothermia-inducing clouds. For most of Fall and Winter, Mt. Fuji is an inhospitable icy wasteland, and during most of the Summer, a tourist zoo. However, with the perfect timing, weather, and preparation, it can be the epic playground for advanced mountaineers and vertical athletes.

Every summer, the topic of "Bullet Climbing" Mt. Fuji arises in foreigner hiking groups in Japan. Is it possible to climb Mount Fuji without resting in one of the huts? Is it possible to do it during the day between the first bus and last bus? If I want to attempt such a silly thing, how should I prepare myself and my friends? In this blog article, I want to share my approach to Bullet climbing, not just Mount fuji, but for other extended objectives which are meant to be completed within one day, forsaking the need to sleep in a tent or a hut.

On July 13, 2022, Japanese trail runner Ruy Ueda set a world record and climbed Mt. Fuji 4 times in less than 10 hours in an event called the "Fuji One Stroke." I was inspired by this incredible feat, and wanted to see if I could even get close to what he did. 

On September 11, 2022, I decided to test my limits and attempted a "Half-Stroke" or "Double-Bullet-Climb" of Mt. Fuji. My goal was to start from the Fujinomiya trailhead, make it to the 5th station of the Fujiyoshida trailhead, and back within 10 hours - the time between the first and last bus of the Fujinomiya trailhead.

I made it in 9h. You can see the stats for yourself here. For those of you without Strava:

• 28.5km

• 3100m ascent

• 9h14m

• 19:26 pace/km

• 4383kcal burned

• Times are approximate:

  • First Climb: 2h30m

  • First Descent: 1h40m

  • Second Climb: 3h30m

  • Second Descent: 1h10m

  • Idle time: 2h5m

This challenge was a grueling endeavor which left me sore for days. I did not experience any altitude symptoms other than a slight headache and reduced physical output, but I had also trained at that altitude several times this year (This was my 9th time climbing Mt. Fuji, 3rd/4th time this year). For the record, I have been quite prone to altitude sickness in the past, getting severe headaches and nausea on my first and second climbs of Mt. Fuji. Even though I was only able to accomplish half of what Ruy Ueda did, it felt very gratifying looking back at my progress over the years and seeing how much stronger I've become.

Bullet climbing is not for everyone. I only recommend bullet climbing if:

• You have experience climbing mountains 3000m or higher OR have climbed Mt. Fuji before

• You can run 10km in about 1 hour

• You have been above 3000m in the past and understand your reaction to elevation sickness at that altitude

Of course, none of you are going to listen to that, so I've tried to be as transparent in this blog as possible in hopes of educating those who are really interested in bullet climbing.

I am not a mountain guide.

The point of this post, despite the title, is NOT to give instruction on how to climb Mt. Fuji. I do not hold a mountain guide license, but I have spent many days in the mountains of Japan, including 9 ascents of Mt. Fuji during both snowy and snowless seasons. I also hold AST-1 and Wilderness First Responder certifications. This post is meant to provide readers with a few of my personal philosophies and perspectives to climbing mountains, and provide insight into the world of mountaineering. This blog is not sound advice for beginner mountain climbers. And for those of you confident hikers who are reading this, I hope that some of these ideas help you stay safe in the mountains, or give you a new perspective that you might enjoy.

Thinking about Risk and Responsibility

The first thing I would like to talk about is risk assessment. As a backcountry skier, mountain biker, rock climber, and participant in many other high-risk activities, I would like to believe that I have some experience in the subject. 

My approach to risk assessment starts from analyzing the dangers of a particular objective and relative probabilities of them occurring. 

Dangers refers to dangers to the human body, especially those stemming from external threats. Some of the biggest dangers we face when hiking are trauma, stroke, and hypothermia. It is also important to note that these dangers are not independent, one can lead to another. For example, early stages of heat stroke, or heat exhaustion, can cause a hiker to be confused, make bad decisions, or even lose coordination and trip and fall, leading to a trauma problem. A trauma patient, like someone who twisted their ankle, may be unable to move, and in turn be in danger of getting hypothermia in a cold environment.

Relative Probabilities refers to the likelihood of one of these dangers occurring. The danger of hypothermia is more probable during a rainy, windy day than a calm, sunny day, so it makes sense to wait for good weather to minimize risk. Running can increase the probability of trauma, and staying still can increase the probability of getting hypothermia. 

I haven't even started to talk about pre-existing conditions, but I'm sure you can imagine what those might add to the mix. I've also only discussed risk to life - you must also think about risk to equipment/financial risk, risk to others, and risk to the environment as a part of your responsibilities as a mountaineer.

Risk is not alone - it also comes with rewards. These rewards could be something like saving time, saving money, getting a better view, or even bragging rights. Whether these rewards are worth taking the risk is up to your own personal judgement. However, many things can cloud our judgement, including Summit Fever (intense desire to complete the objective), peer pressure, or sickness/exhaustion. I know I personally am susceptible to all three of those, so to help guide my risk-assessment decision-making process, I've sworn it upon myself to be responsible.

I believe that as a Mountaineer, we have several responsibilities. Here are a few "rules" I remind myself of in order to be a responsible risk-taker.

• Don't cause harm to yourself

• Don't put others (including possible rescuers) in danger

• Don't harm the environment/leave no trace

• Make your time in the mountains enjoyable for everyone around you

Always remember that your decisions can affect others' experiences in the mountains. Running is high-risk not only for yourself, but also for others below you who might get hit by rocks that you may kick up. Calling for a rescue, especially during foul weather, can put rescue teams in danger. Of course, it is up to your best judgement to make decisions responsibly, balancing the risks and rewards for yourself and others to try to make the best experience for everyone.

Planning and Preparation Pt. 1: Choosing the Day

So, when is the best time to Bullet Climb Fuji? 

For hiking/running, I prefer to go immediately after the climbing season ends, because I know I can prepare myself enough to survive a day on the mountain unassisted. It will be less stressful for less-experienced hikers to go during the climbing season so that they can rest indoors and buy food and water if needed. Going immediately before/after the climbing season allows climbers to reap the benefits of reasonable climbing temperatures/dry trails and fewer crowds. Many people on the trails can be more dangerous due to rockfall. Weekdays during the climbing season could also be a good compromise between fewer crowds and availability of mountain huts.

However, one of the biggest reasons to go off-season is that going off-season also grants private car access to the higher trailheads, like the Fujinomiya, Fujiyoshida, and Subashiri trailheads. This allows you to be more flexible with climbing during the day, with less pressure to start and stop your hike within a specific timeframe. Sleeping at the 5th station at some of the higher trailheads can also grant a bit of acclimatization bonuses, as I will discuss in the last section briefly.

Please keep in mind that when I refer to "Off-season," I'm referring to the weeks without snow immediately before and after the official climbing season starts, like July or September.

Weather is an incredibly important variable in the decision-making process that is mountaineering. Good weather not only is more pleasant for views and moderate temperatures, but it can also make it easier for rescue crews to reach people in need. My four biggest weather concerns when mountaineering are precipitation, cloud cover, wind, and temperature.

I only go to Mount Fuji if the forecast suggests that it will be completely clear. 

Precipitation increases the risk of slipping and falling, hypothermia, and decreases visibility. It is possible to climb Mount Fuji in the rain, but bullet climbing in the rain is obviously quite dangerous. 

Wind can throw you off balance, and will chill you a lot more than expected. Be sure to check not only the speed of the wind, but also the presence of significant Wind Gusts which can throw you off-balance and Wind Direction to understand which side of the mountain may have more wind cover. 

Cloud Cover/Sun Exposure can also affect temperature. Even if you are fine with missing the beautiful views that a cloudless day on not Fuji has to offer, please keep in mind that your body can feel much warmer in the Sun than it does in the clouds. For example, even though the air temperature was warmer at 3000 m than at the summit, I felt my hands going numb because the sun was hidden behind clouds. However, when I got to the summit, the clouds cleared and felt like I could comfortably take a nap lying in the sun despite the single digit air temperatures. 

Being in the shade, especially when the sun starts to dip lower and the North faces of the mountain become shaded in the mid-late afternoon can have a similar, if not more drastic effect.

Temperature is a bit harder to predict, and forecasts tend to be quite off. I tend to avoid running Mt. Fuji if Mountain Forecast says that the temperature (with wind chill) will be below 0°C at the summit because I don't want to bring heavy jackets/insulation, and generally avoid climbing it altogether if the coldest temperature on the forecast reads below -10°C at the summit. Another thing to consider is that even if you don't mind colder temperatures, an injury that immobilizes you will make you become much colder than you might expect.

The weather forecast can change drastically in the course of one week, especially during the August-October Typhoon Season, but usually stabilizes about 2 days in advance. It is important to check the weather the night before the event and be okay with canceling or postponing if the weather makes a turn for the worse. Rain or shine is not an option when dealing with high-risk mountaineering activities.

Make sure that you have a large weather window when planning your climb. When planning a high-risk activity like trail running, I generally like to have at least 4 hours of clear weather AFTER my predicted end-time just in case something goes terribly wrong. Mt. Fuji is mostly very porous volcanic rock, so rain doesn't have a lasting effect on the trails, but if you're thinking about other hikes in Japan, remember that rain can make rocks slippery, trails muddy, and increase the chance of rockfall in areas with steep walls/canyons like the Northern Alps.

Climbing at night can put you at the summit just in time to catch a very rewarding sunrise, and give you more time to descend slowly and catch the bus the next day. However, keep in mind that visibility will be limited to whatever you can see with your headlamp, and without the sun, it will be much colder than you might expect for the given air temperature. I have climbed Mt. Fuji twice and night and seven times during the day (as of September 2022), and can say that both have their merits and demerits.

Planning and Preparation Pt. 2: Preparing the Gear

To prepare for the actual event of climbing Mount Fuji, I like to think about two things: gear, and the body.

My approach to mountaineering gear is quite simple: Footwear, Base layers, Shells, Insulation, Protection, Gadgets, Rations, and Bag.

Footwear: I want something that I know I can wear comfortably and run/hike in comfortably for at least 12 hours straight. I generally stay away from waterproof shoes when trail running, especially because sweat can accumulate inside and wet skin is easier to blister, but waterproof boots can be very helpful for colder, wetter days. For socks, I usually only wear one pair. A midweight wool sock works the best for me whether I'm using boots or trail running shoes, and I prefer longer Crew-length socks to give my ankles and calves a bit more protection.

Base Layers: For pants and shirt, I usually go with something that gives me a balance of breathability and protection. On Mt. Fuji, I want protection from the sun and cold. In the summer, I will often wear shorts and a t-shirt, but I will also carry arm and leg covers with me so that I can put them on if I want to adjust my temperature. Also, sweat degrades Gore-Tex, so I like to have some sort of layer between my skin and the Gore-Tex to soak up the sweat and elongate the life of my expensive shells. As for material, wool or synthetic fibers are highly recommended, as cotton will absorb water/sweat and become extremely cold. 

Shells: Even if there is a very low chance of wind or rain, wearing the shell itself can keep you warm. The reason is because evaporation of moisture from your skin is slowed, which slows the loss of heat energy to the environment. A vinyl raincoat that completely stops evaporation may keep you very warm at first, but eventually, you may become soaked in your own sweat, making you cold again. Therefore, a breathable membrane like Pertex or Gore-Tex is recommended. 

For a Jacket, recommend a Gore-Tex Shakedry piece like Montbell's Peak Dry Shell because of its lightness, breathability, and superior waterproofness and water repellency. The downside is its durability, but I've fallen a few times on rocks and have yet to find a single scratch.

For rain pants, I don't care so much about waterproofness unless I am expecting rain or snow. I recommend Gore-Tex Infinium shell pants for packability, lightness, and breathability, like this one here. I've actually worn the cycling version of this piece through quite a few rain storms, my legs have stayed relatively dry. Do note that Gore-Tex Infinium is NOT advertised as waterproof.

Insulation: For temperatures over 10°C, I usually don't wear insulation during activity to avoid sweating, but a puffy jacket can increase comfort and prevent hypothermia during periods of rest or inactivity. I always bring an insulation piece, like this ultra lightweight down jacket by Montbell, even if I don't expect to use it. I generally don't bring insulation for my legs unless I'm planning on spending the night, but I will always bring a Bivy (more on that below).

Protection: I will always bring a hat, not just to keep the sun and wind off of my face and head, but also to keep me warm (your head is one of the parts of the body that loses the most heat). I will always bring sunglasses despite the weather forecast, and I will always pack extra sunscreen. Gaiters are optional, but I like to wear them because rocks getting inside my shoes can be quite annoying. Gaiters are much more important in the snow.

I usually bring an emergency bivy bag with me like the SOL Emergency Bivy. It's basically one of those metal emergency blankets, but sewn into a bag. This can keep you warm while waiting for rescue if you become injured/immobile. Even if I think the risk of me becoming immobile is extremely low, I almost always keep one in my pack in case I come across somebody who is in that situation. A metal blanket will also work, but the bag can prevent evaporation and keep you warmer.

A good first aid kit is important, but knowing basic first aid is even more important. First-aid knowledge is, in my opinion, more important than any kind of first-aid kit, and I recommend taking a Wilderness First Aid class for anyone serious about outdoor adventures. In general, I will carry bandages, gauze tape, medical tape, povidone iodine, NSAIDs/Acetaminophen, antihistamines, and an ace bandage.

Gadgets: Your smartphone is one of the most useful tools on the mountain in terms of reaching rescue and preventing yourself from getting lost. If you haven't already familiarized yourself with GPS mapping softwares and applications that can be downloaded onto your phone, make sure you spend some time doing so before you head out to the mountains next. Getting lost in the mountains can be extremely dangerous, and while the the chances of getting lost on Mount Fuji are quite low, GPS mapping softwares can also provide you with other valuable information. Stats like elevation, distances, and time can help you make important decisions like budgeting food and water, viability of reaching the summit within the chosen timeframe or choosing a good turnaround point. Even without cellular service (which is quite available on Mt. Fuji, as well as many other mountains in Japan), many of these apps can download maps to use offline, as GPS does not require mobile data to use. As my phone is such an important device for mountaineering, I will always bring a power bank to make sure that I have enough battery to last for at least several hours longer than what I have planned on the mountain.

A headlamp is another must-have for me on the mountain. Headlamps can increase our effective time on the mountain, allowing us to navigate safely outside of sunlight hours. I never leave home without one. Flashlights don't allow us to use our hands for balance or support, and the smartphone flashlight should obviously only be used as a last resort.

Duct tape can solve many problems, like holes in clothing or bags. I wrap some around a lighter or pen and throw it in my first aid kit. Also, don't forget the toilet paper.

Many people doubt the usefulness of hiking poles, but I highly recommend them. Even if they don't provide upward propulsion (they can, with enough upper-body training), they can help give you balance and stability when walking over the uneven/slippery surfaces found on some of Mt. Fuji's sandy slopes, and reduce the risk of falling.

Rations: As for preparing food and water, it takes a lot of experience for you to know how much your body needs while you are doing the events. I generally budget about 100 to 200 calories per hour depending on the intensity of the activity, and usually budget about 1 L of water for every 4 hours of activity in cool climates and 1.5 to 2 L of water for for every 4 hours of activity in warmer climates. 

For my "Double Climb" of Mount Fuji, where I climbed from the Fujinomiya 5th station to the summit, descended to the Fujiyoshida 5th station, and made the trip back again, I used 2.5 L of water over the total 9 hours, which was barely enough. During the hike, I also consumed approximately 1100 calories, which was barely enough.

Bag: A good bag is important for any sort of hiking. The first time I climbed Mt. Fuji, I used a very simple inexpensive backpack to carry all my things, and it was completely fine.  For my Double-Climb, I used a high-tech running vest, and it was also fine. Here are a few guidelines I have for backpacks:

• Should be comfortable

• Should hold all your gear, with maybe a little extra space

• Should be durable enough to withstand some falls or drops

• Should not be too heavy

I'm sure I've forgotten or left out a few things, but that's mostly it! Below is a picture of everything I brought to my Double-Fuji-Climb in my pack or on my body (excluding the KT tape on my knees and energy gels that I consumed). 

Planning and Preparation Pt. 3: Preparing the Body and Estimating Course Time

Preparing your body for hiking Mount Fuji is kind of like preparing your body for running a marathon. However, running a marathon unprepared has minimal risk of severe consequences, whereas hiking a mountain unprepared could put you in a lot of danger. I hate to say it, but mountaineering is an extremely ableist sport. It's difficult to make a general rule of how fit one should be before attempting to climb a mountain. The more fit you are, the lower your risk of getting injured is, and the higher your chances are of self-rescue if something happens on the mountain. In general, as someone who is often responsible for others in the wilderness, I try to make sure that I can run the distance of the hike near my house before attempting it. Even if you don't plan on running during your hike, running is a pretty good measure of fitness and can help you imagine how tiring the hike will be before adding your backpack, boots, and elevation gain. In some cases, it can also increase your confidence, knowing that if you need to escape quickly for whatever reason, you would have the physical prowess to do so.

In terms of calculating speed, on flat surfaces, most hikers cover about 3 km to 5 km per hour. However, for objectives like Mount Fuji, I generally think about elevation rather than thinking about distance. Climbing speed, or the amount of meters gained per hour, is one of the most accurate ways of determining course time for Mount Fuji because of the consistency of of the grade and low technicality of the trails. It's difficult to say how fast the average hiker would climb, but in my experience, it's usually between 150 to 350 m/h. For reference, I reached the summit of Mount Fuji during the first leg of my double-climb in about 2 hours and 30 minutes. Starting from the Fujinomiya trailhead, that would mean I climbed a total of about 1,400 m, making my average climbing speed about 560 m/h. There were some hikers who I talked to that day who took 10 hours to summit, making their average climbing speed 140 m/h.

It is also important to consider the time it takes to descend the mountain, and this can be drastically different depending on the trail you choose and your confidence on navigating three slopes. If you've never hiked on loose volcanic rock before, it can be very difficult to predict this. Some people are comfortable with running down the volcanic sand found on the Subashiri Trail, and can descend in less than 3 hours. Some people may feel afraid of slipping, and it may take them four to five hours to descend. Make sure you consider this when calculating your time to finish the course. Once you know this, subtract it from the total time you have, and from that, you can calculate a goal climbing speed.

For example, if I estimate it will take me 4 hours to descend, and I have 10 hours between the first bus and the last bus, this means that I will only have 6 hours to reach the summit. If I am climbing from the Fujinomiya side, that will mean I need to climb 1,400 m in 6 hours, giving me a goal speed of 233m/h.

If you want another statistic to reference, my half marathon time (at the time of writing) is about 1 hour and 50 minutes, and I can run a 5k in about 20 minutes. I also train hill-climbs on a bicycle and do a lot of backcountry skiing, so I have a lot of "uphill experience." If your stats are similar to mine, altitude sickness barring, you should be able to complete the Fuji "Bullet Climb."

If all this calculation seems a little difficult or unrealistic for you, there are maps with suggested course times written on them. Yama to Kogen is the name of one of the most famous hiking map series in japan, and the information from their maps can also be found in common Japanese mountaineering apps like Yamap and YamaReco.

Final Thoughts, some "Tips and Tricks"

So you've gotten all your gear ready, run a 10K, and double-checked the weather forecast. Everything looks ready to go. A few more things I think about before heading out:

Altitude sickness: Ah yes, the big one that I've only mentioned briefly. Elevation sickness is one of the main factors holding most of us back from bullet-climbing. In order to acclimate to the thinner air at higher elevations, the body needs to acclimate slowly. I've heard some of my more experienced mountaineer friends say that the recommended rate of ascent to balance between speed and proper acclimatization for Mt. Fuji is approx. 200m/h. I am unsure of any "official" recommended rates of ascent, but various sources say that it is not recommended to ascend more than 300m per day above 3000m.

Diamox (Acetazolamide) and Dexamethasone are two drugs used to combat symptoms of Accute Mountain Sickness, or Altitude Sickness. I have never taken either of these drugs, but if you are extremely concerned about AMS, they might be worth asking your doctor about.

In my experience, sleeping at the 5th station helps a lot. One of the reasons I like climbing "Off-Season" is because I can sleep in my car at the 5th station of Subashiri, Gotemba, and Fujinomiya trailheads, allowing for inexpensive lodging and acclimatization in the same package.

Pre-gaming Food and Water: I will often over-eat and over-drink before the start of a hike. I've done this many times before, and DO NOT recommend you to try changing your diet right before a hike for obvious reasons. However, this strategy has allowed me to carry a little bit less food and water on my day hikes.

Workers on the Mountain: On my last climb, one of the workers climbing the trail to one of the huts told me that the trail was closed, and that I shouldn't be on it. He also said to "be careful." Another told me to "Ganbatte," or to "try my best." So far as I know, there are no laws against climbing Mt. Fuji "Off-Season," but if you do, please keep in mind that hut workers on the mountain are either preparing to open or close the huts, and may need to use the trail space to make their jobs easier. Make sure to be responsible, and treat them with respect - don't get in their way, so that they keep the restrictions as lax as they are now.

Fitness Watches: I almost always wear a fitness watch. They are a very good way of helping me keep track of my pace and relative status of my body (heart rate). I highly recommend one for anyone getting serious about mountaineering.

Caffeine: In my experiences, caffeine has actually been helpful for me at altitude, but be aware of its dehydrating diuretic effects and make sure you have ample water to offset this. Caffeine has been a good performance-enhancing drug for me (being someone who almost never consumes it), but it also makes my stomach feel a bit queasy sometimes, which is not great in a wilderness context.

Cancellation/Plan B: In the case of foul weather, it is obvious to cancel or postpone a climb, but it can also be tempting to go through with it, especially if you've already made plans with friends. In order to reduce the stress and disappointment of cancellation, have a "Plan B" - that way, even if the weather doesn't hold, you'll still have something fun to do with your friends, and won't be as motivated as to take unnecessary risks.

Bailing/Cutting it Short: Be aware that some of the descent trails, especially on the Fujiyoshida trail, can only be accessed from certain points on the mountain. In the case that you decide that you want to cut your climb short, it may be helpful to first locate the next "down" trail before heading down - if it's only a few meters climb up ahead, it be a lot easier than "going against the flow" and also down-climbing terrain that was only meant to be climbed.

Get out there and climb some mountains!