In Part 4.3, we talked about all the different types of running data that you can collect and what they mean. As the distance and time spent on your feet accumulate, some discomfort, soreness, or small “niggles” become almost unavoidable. As I also mentioned in the previous post, an abnormal HRV for me often predicts an oncoming injury with surprising accuracy.
In this post, I will talk about the injuries that I suffered during my freshman year of running, what I learned from them, and how they changed the way I approach training. I hope that some of these experiences and insights will help you on your own running journey as well.
Disclaimer
This post is not intended to help diagnose or manage a new or existing injury. You should always see your own physician or healthcare provider for proper assessment and treatment recommendations. The internet as a whole is not very reliable when it comes to diagnosing injuries, and incorrect treatment can sometimes worsen the condition.
This post is simply a documentation of my own anecdotal experiences with different running-related injuries, along with reflections on what I learned from them.
To make life easier for you, here is a table of contents of the injuries that I will cover, so you can skip directly to the sections that interest you most. Of course, you are also welcome to read through the entire post from beginning to end and witness my full year of suffering.
- June 2025: Dorsal Foot / Metatarsal Pain
- August 2025: Quadriceps Strain
- October 2025: Foot Strain / Plantar Fasciitis
- November 2025: Shin Splints
- February 2026: Shoulder Impingement (not running related)
- April 2026: Quadriceps Cramp / Strain
- May 2026: Iliotibial Band Syndrome
- Date TBD: Patellar Tendonitis
- Date TBD: Achilles Tendonopathy / Tear
When reading this post, you might be thinking:
“Wow Dr. Dai, you sure injure yourself a lot.”
My answer is:
“Yes, I did — and hopefully I can leave that in the past tense.”
The reason is simple. During my first year of running, I set myself an ambitious goal: to run a sub-3-hour marathon. To pursue that goal, I had to push myself close to the edge between optimal performance gains and overtraining.
The line between productive training and injury is actually much thinner than most people realize. Because I was inexperienced, there were many times when I did not realize I was overtrained until it was already too late.
I often joke that for myself, it is acceptable to get each type of injury once — because then I can learn from it. But it is not acceptable to get the same injury a second time, because that means I failed to learn the lesson.
I also want to make one controversial comment:
If a runner has never been injured before, they probably were not training aggressively enough to truly discover their limits.
That does not mean injuries are good. They are not. But if you constantly push toward the limits of your body, mistakes and setbacks become part of the learning process.
Writing about my injury history also gives me a chance to reflect and reinforce what not to do in the future.
June 2025: Dorsal Foot / Metatarsal Pain
In May 2025, I set a goal to complete a marathon in under 3 hours within a year. After a lot of research, I realized that while the goal was improbable, it was not impossible for someone willing to fully commit to it.
One of the keys to running faster is simple: run more.
Weekly mileage has a strong correlation with long-distance running performance, and many sub-3-hour marathon runners consistently train close to 100 km per week.
So over the summer of 2025, I gave myself a goal of gradually reaching 100 km/week by October 2025 — the halfway point toward my marathon and also the timing of the Vancouver UBC Great Trek Half Marathon, which I planned to use as a fitness benchmark.
Around this time, I bought three pairs of the same running shoe: the Saucony Endorphin Speed 3. They were highly recommended by a runner working at Sport Chek, so I decided to give them a try.
The shoes initially worked quite well. They had good cushioning and a nylon plate, which acted as a hybrid between a traditional training shoe and a supershoe.
In June 2025, during one of my easy runs, I gradually developed discomfort over the top of my left foot between the great toe and ankle — around the first metatarsal region. The discomfort built up over roughly 100 meters. I initially ignored it, expecting it to fade away, but within about 15 seconds it escalated into sharp pain severe enough that I had to stop completely.
I ended up calling my wife to pick me up because I could not even walk home.
This became my first major injury during marathon training, and mentally it was devastating. My aerobic fitness was clearly improving, my easy pace was becoming faster, and I had just begun incorporating structured speed sessions. Suddenly, everything came to a halt.
The worst-case scenario that immediately crossed my mind was a metatarsal stress fracture.
Because stress fractures can worsen into more serious fractures requiring surgery — and potentially lead to long-term disability — I stopped running completely to allow recovery. Since early stress fractures may not show up on X-rays during the first couple of weeks, I deferred imaging initially and instead focused on cycling and strength training.
Over the following weeks, through repeated self-examination and research, I became increasingly confident that this was not actually a stress fracture, but rather extensor tendon irritation over the dorsal first metatarsal.
The key clue was this:
I had no pain while barefoot.
As soon as I wore the Saucony Endorphin Speed 3s, the pain returned almost immediately.
I started testing different shoes at running stores and realized that some reproduced the pain while others did not. Eventually I noticed that the problematic shoes all had a protruding seam beneath the tongue of the shoe, which repeatedly irritated the tendon on the top of my foot.
Once I identified the root cause, I removed the insoles and loosened the lacing pattern around the tongue. The problem improved almost immediately.
Lessons Learned
Your shoes matter.
A shoe that works perfectly for one runner may not work for another. The internet overwhelmingly praised the Endorphin Speed 3, but all feet are different.
Also, do not buy multiple pairs of the same shoe until you have accumulated substantial mileage on the first pair.
Otherwise you may end up with three expensive pairs that your feet hate — like I did.
August 2025: Quadriceps Strain
After my foot problem from June 2025 resolved, I resumed running and gradually ramped my mileage back up. I was running around BCIT, a local technical school, almost exclusively at the time. The routes had long sections of steep uphills and downhills. The uphills were brutally difficult, but the downhills felt fast and effortless. I felt like I could fly downhill and make up all the time I lost climbing uphill.
Running downhill felt amazing. I was moving quickly without feeling overly fatigued, and my heart rate stayed relatively low. From a cardiovascular perspective, it felt easy.
Then one day in August, during a downhill section, I felt a mild discomfort in my right quadriceps muscle (front of the thigh). I kept running, hoping it would fade away, but the discomfort gradually turned into what felt like a ripping sensation. Realizing this was probably another injury, I stopped immediately. At least this time I was able to walk home on my own and did not need to call my wife for rescue.
The diagnosis was fairly obvious: a quadriceps strain, likely caused by downhill running and too much of something called eccentric loading.
Muscles can generate force in two main ways: by shortening while contracting, or by contracting while lengthened. The former is called a concentric contraction, while the latter is called an eccentric contraction.
During downhill running, the quadriceps are placed under significant eccentric load because they are constantly working to brake and stabilize the body while preventing you from falling forward. As your foot strikes the ground downhill, the quadriceps contract while lengthened, which places substantially higher stress on the muscle fibers.
What happened to me was fairly straightforward in retrospect. Since downhill running felt easier from a breathing and cardiovascular standpoint, I naturally sped up. However, while my heart and lungs were comfortable, my legs were not strong enough to tolerate the additional speed, impact, and eccentric loading. Eventually the quadriceps simply could not handle the stress anymore, and something gave way.
This injury sidelined me for a couple of weeks. Fortunately, I already had a two-week vacation booked around that time, so it gave me an excuse to reduce training during the trip. Two weeks ended up being enough time for recovery.
With this injury, I could not tolerate either uphill or downhill running. I could not even bike comfortably because cycling also requires significant quadriceps activation.
Lessons Learned
You need to allow every part of the body time to catch up to your cardiovascular fitness.
My heart was ready, but my legs were not — especially for aggressive downhill running.
After this injury, I started respecting downhills much more. I became more mindful of my quadriceps while descending, increased my cadence to reduce loading, and stopped trying to “overrun” down steep hills simply because it felt easy aerobically.
October 2025: Foot Strain / Plantar Fasciitis
After recovering from the quadriceps injury and returning from vacation, I resumed training. The UBC Great Trek Half Marathon was coming up at the end of October, so I transitioned into more specific half marathon training. This included more race-specific workouts and sessions at half marathon pace or faster.
As planned, I eventually ramped my weekly mileage up to 100 km/week.
Then, about two weeks before the race, at the end of one of my long runs, I suddenly felt a pop on the bottom of my left midfoot. I stopped immediately.
There was no significant pain initially, but since the race was so close, I did not want to take any risks. About half an hour later, a dull ache began developing, and the discomfort progressively worsened over the next day.
Based on self-examination, I felt this was likely a combination of early plantar fasciitis and a strain involving the flexor hallucis longus (FHL), an important muscle and tendon system running along the inner and bottom portion of the foot that plays a major role in push-off during running.
This injury sidelined me for the next two weeks. During that time, I did as much cross-training as possible with cycling and inclined walking to try to preserve fitness. I also focused heavily on rehabilitation, including warm soaks, gentle massage, stretching, strengthening exercises, and mobility work in an attempt to expedite recovery.
By race day, I honestly was not sure whether I could complete the distance or whether the foot pain would flare up again during the race.
I gave it my best effort and completed my first ever half marathon in 1:36:50.
Fortunately, my left foot held up surprisingly well during the race. However, I developed a severe left calf cramp around the 13 km mark — something I will talk about later in this post.
Lessons Learned
Sometimes injuries creep up on you when you least expect them.
I had absolutely no warning signs throughout the entire half marathon training block until two weeks before race day.
In retrospect, I may have ramped my training volume too aggressively. The overall pattern remained the same: my cardiovascular fitness was improving faster than my musculoskeletal system could adapt.
This injury also made me realize that foot strengthening exercises are extremely important for runners — something I incorporated into my routine afterward.
November 2025: Shin Splints
During my half marathon at the end of October 2025, I developed a horrible left calf cramp around the 13 km mark. It was probably a combination of adrenaline and sheer stubbornness — not wanting to DNF (Did Not Finish) my first half marathon — that allowed me to push through the pain and finish the race.
After the race, I rested for four days. My legs felt relatively normal again, so I returned to easy running and even did a hill speed session one week after the half marathon.
That turned out to be a mistake.
During the workout, I developed pain along the middle portion of my left shin. Over the following few days, the pain progressively worsened. I suspected the dreaded “shin splints,” and unfortunately I was right.
This injury sidelined me from running for nearly two and a half months.
Shin splints, also known as medial tibial stress syndrome, are an overuse injury involving irritation of the tissues and muscles attached to the shin bone (tibia). They are commonly caused by excessive training volume, rapid increases in intensity, inadequate recovery, or repetitive impact loading.
I went through a long rehabilitation period largely on my own. I cross-trained extensively on the bike and also decided to finally learn how to swim properly as an adult.
For context, I had never truly learned how to swim after a near-drowning experience at age eight. You can read about the story in Part 2.
And naturally — because apparently I enjoy making questionable decisions — I also signed up for a triathlon scheduled for March 2026.
Since I couldn’t run, I started going to the pool seven days a week. Eventually the shin splints improved, but the injury still set my marathon training back by nearly three months.
Unfortunately, the left calf cramp also continued to return intermittently.
One memorable episode happened during a casual swim session with my friend and colleague, Dr. Billy Lin. While swimming in the exact middle of a 50-meter lane at the UBC Aquatic Centre — literally the furthest possible point from either wall — my left calf suddenly cramped again.
I panicked quite a bit.
The situation immediately brought back memories of my childhood near-drowning incident. I managed to slowly swim the remaining 25 meters back to the edge of the pool while enduring the cramp, but that effectively ended the session for the day. My calf remained painful for the next couple of weeks afterward.
Overall, these few months were a real struggle. It was one of the most difficult periods I had experienced emotionally during my running journey. Not being able to run took a surprisingly large toll on my mental health.
Lessons Learned
Respect post-race recovery.
In retrospect, I returned to training far too quickly after the half marathon. I probably should have taken 1–2 full weeks completely off before easing back into running.
I was too eager to “ride the fitness” from my half marathon training and carry that momentum directly into my marathon block. That ended up being a major mistake.
I also suspect that the shin splints may have been triggered, at least partially, by the calf cramp itself. Persistent calf tightness can increase pulling forces on the shin bone and surrounding tissues, eventually contributing to shin splints.
Most importantly, this injury made me realize how deeply running had become part of my identity.
For the first time in my life, I felt that I genuinely could not be happy without regular running. In one sense, that represented a positive identity shift — running had become a meaningful part of who I was. But psychologically, it also meant that injuries affected my mood far more than I expected.
February 2026: Shoulder Impingement
Not exactly a running related injury, but I’ll put it here anyways. Since I could not run because of the shin splints, and because I still had a triathlon to prepare for, I decided to fully commit to swimming.
Initially I trained on my own and occasionally with friends, but eventually I started working with 4-time Olympian Brent Hayden as my swim coach.
Under his expert guidance, I progressed very quickly.
People at the pool were often shocked when they found out that I was actually a beginner swimmer. Lifeguards occasionally commented that I swam like someone who had trained for years.
At one point, I was swimming 14 sessions per week — yes, twice per day — because I became obsessed with improving my technique and speed.
In retrospect, I was very clearly overtraining, despite Brent warning me repeatedly about it. He literally told me that I needed to relax more and stop being so uptight.
Unwisely, I ignored an Olympian’s advice.
Eventually, I started developing pain deep inside both shoulders, particularly in the back of the joints, with the right side being significantly worse than the left. The pain gradually worsened to the point where I could barely swim more than 50 meters continuously.
I developed shoulder impingement syndrome, an overuse injury where inflamed shoulder tendons become compressed within the limited space of the shoulder joint. The swelling causes less room for movement, which then creates even more irritation and impingement.
At one point, I even considered corticosteroid injections or potentially withdrawing from the triathlon altogether.
But if you know me by now, you know I am stubborn like a bull.
After a couple weeks of rest, I still decided to attempt the UBC Sprint Triathlon in March 2026. Unfortunately, during the swim portion I was visibly struggling because of the shoulder pain, and the lifeguards pulled me from the water and disqualified me from the race.
To their credit, they still allowed me to complete the bike and run portions afterward, so at least I got my medal.
Even during the bike and run sections, every road bump and every arm swing caused significant shoulder pain.
Officially, it was a DQ.
But honestly, it was still an incredibly valuable learning experience. It was my first triathlon, my first exposure to the complexity and logistics of multisport racing, and despite everything, I still enjoyed the experience.
I definitely plan to return to triathlon one day for redemption.
After the race, I stopped swimming entirely and shifted my focus back toward preparing for the Sun Run 10K on April 19, 2026 and the BMO Vancouver Marathon two weeks later on May 3, 2026.
Lessons Learned
I was too stubborn for my own good.
I was obviously overtraining, but I refused to listen to advice from others — even from an Olympian — because I convinced myself that “more is better.”
The triathlon disqualification was emotionally devastating for me, and it took a long period of reflection afterward to process it properly.
I also realized something important about myself, though I am still not sure whether it is a good thing or a bad thing:
- I can tolerate a lot of pain.
If the lifeguards had not pulled me from the pool, I probably would have finished the swim even if my arms were about to fall off.
April 2026: Quadriceps Cramp / Strain
Yes, I know that earlier I said: “Do not get the same injury twice,” and here I am talking about another quadriceps injury.
However, I will give myself a pass on this one because it happened during a race rather than training, and the mechanism was completely different from the previous quadriceps strain caused by downhill running.
This time, I developed a severe right quadriceps cramp only 1 km into a 10 km race.
This was probably the most frustrating setback of my short running career so far.
After recovering from the shin splints and post-triathlon shoulder issues, I felt that I had finally learned from my previous mistakes. I structured a much safer marathon training block. I incorporated more cross-training, increased volume more gradually, prioritized sleep and nutrition, and paid much closer attention to how my body was feeling.
Honestly, it was an excellent training block.
My training data strongly suggested I was in shape for a sub-38-minute 10K and potentially even a sub-3-hour marathon.
I went into the Sun Run feeling confident and excited. This race also carried a lot of emotional significance for me. It was the race that originally got me into running and motivated my entire transformation journey. I was hoping for a major personal best.
On race day, I started conservatively at slightly slower than goal pace.
Then, about 1 km into the race, I felt a small niggle in my right quadriceps.
Within another minute, that niggle transformed into a full cramp.
With 9 km still remaining, I seriously considered dropping out. The finish line felt impossibly far away, and with my first marathon only two weeks later, I was worried about creating an injury severe enough that I would not recover in time.
After a lot of internal debate — and several moments where I nearly gave up — I convinced myself that I needed to cross that finish line.
So I slowed down to a safer pace and continued. Downhills significantly aggravated the quadriceps pain, and frustratingly, I had to slow down to an easy Zone 2 pace for most of the downhill sections.
The remaining 9 km were absolutely excruciating.
I ultimately finished the race in 41:05, which was technically a new official personal best, but I was deeply disappointed because I knew I was capable of much more.
Looking back, I think there were several contributing factors.
First, in an attempt to reduce impact-related injuries, I had incorporated large amounts of cycling into my training. While beneficial aerobically, it may also have left my quadriceps chronically fatigued.
Second, the Sun Run occurred only one week after my peak marathon training week of approximately 100 km. My legs were likely not fully recovered from the accumulated fatigue.
Lastly, because I lacked race experience, I was extremely anxious and tense while standing in the starting corral. I was probably far too uptight before the race even began. Over time, I suspect this will improve naturally as I gain more racing experience and become psychologically more relaxed in race environments.
Lessons Learned
Cross-training can also be overdone.
Too much cycling can fatigue the quadriceps and negatively affect running performance.
I also realized that I need to improve my race psychology and relaxation strategies before races.
Lastly, attempting an all-out 10K race during a marathon taper was probably not the smartest idea. In hindsight, I either should have raced more conservatively or simply chosen one primary goal race instead of trying to optimize both simultaneously.
May 2026: Iliotibial Band Syndrome
After the Sun Run on April 19, 2026, I had only two weeks remaining before my first ever marathon.
Having just suffered the quadriceps issue during the 10K race, I did everything I possibly could over those two weeks to recover. I focused heavily on rest, sleep, nutrition, rehabilitation exercises, foam rolling, massage work, and reducing training volume. I also did a proper carbohydrate load before the race.
I went into the marathon feeling both excited and slightly worried that my quadriceps might flare up again.
Even before the race started, my calves and quadriceps were twitching — probably a mixture of nerves and excitement.
The weather conditions were also brutal. It was extremely hot, with almost no cloud cover and very little shade along the course.
Despite this, I had completed a very strong training block and genuinely believed I had a realistic shot at running sub-3 hours.
I started conservatively as planned, aiming for a negative split strategy (running the second half faster than the first). However, even by 5 km, I realized the heat was forcing me to adjust expectations. My lower back was on fire, and at nearly every aid station I was pouring multiple cups of water over myself just to avoid overheating.
Still, through the first 32 km, I actually felt surprisingly strong and controlled. I was not experiencing any significant pain or discomfort.
At around 32 km, I decided to gradually increase the pace and shift my goal toward a sub-3:15 finish.
Then around 35 km, I noticed a slight niggle in my right thigh. It did not feel like a true cramp, so I kept going.
Shortly afterward, severe pain suddenly developed along the outside of my right knee and forced me to come to a complete stop.
I sat down on the side of the course, did a quick self-assessment, and strongly suspected IT band syndrome.
From that point onward, I essentially limped my way to the finish line.
This was by far the worst pain I had experienced out of all my injuries. Unlike previous issues, there was absolutely no possibility of “pushing through it.”
The final 6 km took me nearly 2 hours to complete. My slowest kilometer pace was approximately 25 minutes/km.
Ironically, my final 6 km took almost as long as my first 36 km combined.
I crossed the finish line of my first marathon in 4:44:50.
Despite the painful ending, I still genuinely enjoyed the race atmosphere, the crowd support, and the overall experience. Most importantly, I was proud that I managed to finish and earn my first marathon medal.
Iliotibial Band Syndrome (ITBS) is an overuse injury involving irritation of the iliotibial band — a thick connective tissue structure running along the outside of the thigh. In runners, it commonly causes pain along the outer aspect of the knee, particularly during longer-distance running.
As of writing this post, I am still recovering from this injury four weeks after the marathon.
This time, I was injured badly enough that I could barely train at all afterward.
Honestly, this website itself became part of my coping mechanism. Since I could not run, creating health and running-related content gave me a way to still channel my energy toward something meaningful and connected to the sport.
In the meantime, I have continued rehabilitation exercises, massage work, mobility training, and strengthening exercises, but progress has been frustratingly slow.
Even four weeks later, my knee pain would often return after only about 1 km of running.
Lessons Learned
It is very possible that I never fully recovered from the Sun Run before attempting the marathon two weeks later.
In the future, I may need to either:
- run the Sun Run much more conservatively,
- or simply choose between the Sun Run and the BMO Marathon rather than trying to race both seriously.
This injury also reinforced a major realization:
My cardiovascular system has improved much faster than the rest of my body.
I often describe it like this:
I had a Ferrari engine attached to Toyota wheels.
Cardiovascularly, I was capable of pushing harder, but the muscles, tendons, ligaments, and bones simply were not yet durable enough to tolerate the load.
Because of this, my primary focus for the next training cycle will be runner-specific strength training and improving tissue resilience.
I genuinely believe my aerobic engine is already capable of supporting a sub-3-hour marathon.
The limiting factor now is not my heart and lungs — it is the durability of the hardware carrying them.
This experience also taught me one final lesson:
Anything can happen in a marathon.
Even if everything feels perfect through 35 km, things can still unravel very quickly and unpredictably.
Date TBD: Patellar Tendonitis
One common running injury that I have fortunately not experienced yet is patellar tendonitis, sometimes called “runner’s knee” or “jumper’s knee.”
Hopefully I can keep it that way — knock on wood.
Like many running-related injuries, patellar tendonitis is typically caused by overuse and increasing training load too much, too quickly. It usually presents as pain along the patellar tendon, which connects the kneecap (patella) to the shin bone (tibia).
Date TBD: Achilles Tendonopathy / Tear
Another common running injury, which I have fortunately not experienced myself (knock on wood), is Achilles tendinopathy or more serious Achilles injuries such as partial tears or complete ruptures. These injuries are notoriously difficult to treat because the Achilles tendon has a relatively poor blood supply, which can slow healing and leave runners sidelined for months.
The key to prevention is consistent calf strengthening and, once again, avoiding sudden increases in training volume or intensity. Maintaining adequate recovery and gradually progressing your training load can significantly reduce your risk.
Rehabilitation is often a long and frustrating process that benefits from professional guidance. Treatment typically focuses on progressive strengthening of the gastrocnemius and soleus muscles, gradual reloading of the tendon, and addressing any running form issues or biomechanical factors that may have contributed to the injury in the first place.
________________________________________________________
Given my injury history so far, I jokingly tell myself that I probably still have “quotas” left to experience these last two injuries one time each. But ideally, I would prefer to learn about these ones from textbooks rather than personal experience.
In Summary
I injured myself quite a lot during my freshman year of running, but I also learned an enormous amount from those experiences.
I often joke that I should receive CME (Continuing Medical Education) credits for all the injuries I have suffered, because honestly, they have been incredibly educational.
Going through these injuries has also made me a more knowledgeable and empathetic physician toward patients dealing with similar problems.
If there is one major theme throughout all of these injuries, it is this:
Most running injuries happen when the body is asked to adapt faster than it is capable of adapting.
The key lessons I learned are:
- run your easy runs easy,
- avoid increasing volume too quickly,
- listen to your body,
- prioritize recovery,
- and do not be stubborn-headed
Ultimately, your cardiovascular system often improves much faster than your muscles, tendons, ligaments, bones, and connective tissues. Those structures need time to strengthen and adapt.
Hopefully, by applying those principles, you can avoid many of the injuries that I described throughout this post.
In Part 4.5, I will talk about one of the most important tools for injury prevention and long-term durability: runner-specific strength training.
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