My First 20km Run

I believe that everyone has a “first” for many things in life. This is another one of my firsts, and it’s a step toward another first next week. Today’s first for me was running the longest distance I’ve ever run—my first 20km.

Here’s how it all came about. A week ago, I missed the registration for the CMU Marathon, which I had planned to be my first Half Marathon. Unfortunately, fate wasn’t on my side, and I missed the opportunity to sign up. So, I waited to see if anyone would release a Half Marathon BIB that I could grab.

Finally, fate intervened when a friend of mine who had registered for the full 42km Marathon decided to give up their BIB due to lack of preparation and training. Another friend assured me that I could downgrade to the Half Marathon because I had paid for the full marathon, so I agreed.

The next night, I found myself reading posts in the Ultra & Trail Runners in Thailand group, a community for those who run trail and ultra-marathons (distances beyond the marathon, starting at 43km). As I read, I thought, “If they can run such long distances, then I should be able to as well.”

The first thought that came to my mind was, “Can I really do 42km?” With only two weeks left until the race, the longest distance I had run was just 11km. Doubts started flooding my mind, but I remained determined. “Alright, 42km it is,” I thought. “I’ll start training tomorrow.”

My training plan was simple. I would stick to my usual 5-10km runs, but in the first week, I had to complete at least one 20km run. Four days before the race, I aimed to do a run of 30km or more. But let’s focus on the 20km run first.

Before the run, I bought some gels, specifically GU lemon-flavored gels. That’s the green packet you see above. The consensus among runners is that most gels taste awful, but lemon is the least offensive. How many gels to consume during a race depends on the individual. Some people might only need two gels for a 42km run. These gels provide quick energy that your body can use immediately, helping to sustain your energy levels. Typically, one gel provides about 45 minutes of energy for aerobic-level running, so most people take one every 45 minutes. However, it’s advised not to consume more than four gels (they’re expensive, about 75 baht per packet).

Starting the Run

After work, I geared up with my water bottle and phone and set off on my run. I chose the route you see on the map above, starting from the office, heading to the entrance of Huay Tung Tao, running around the 700th Anniversary Stadium, and then back to the office. This route covers 10km, so doing two laps would make it 20km. The best part about this route is that it has dedicated lanes for running and cycling, making it safer than running on the road.

5km—Smooth and Easy

The first 5km were smooth and easy. I kept myself in check, trying not to drop below a 5-minute pace because I tend to run fast, usually between a 4-5 minute pace, which shortens the distance I can cover. I managed to control my pace well, so I didn’t feel too tired.

10km—Time for the Gel

At the 10km mark, I started to feel tired. Back at the starting point, I tore open a gel packet and consumed it. The taste was as bad as people said, but I had to take it. After 12km, my pace dropped to 6 minutes per kilometer as I started walking more often. My goal was to stay under a 6-minute pace, but as I grew more tired, walking became more frequent.

15km—Should I Stop or Keep Going?

At this point, all the symptoms hit me at once. I started alternating between walking and running while trying to maintain my pace. Thoughts of stopping and walking back flooded my mind—my knee hurt, my heart was racing, and I questioned why I was pushing myself so hard. But then I looked at the time and saw that I had already reached 17km. I shook off all doubts and pushed forward.

20km—Finally, I Did It

When my phone announced that I had reached 20km, I immediately stopped the timer. I had hit my goal, and I was overjoyed—I almost cried. I had done it! I was exhausted in a way that’s hard to describe. My leg muscles were completely worn out, and my knee pain had returned. Looking at the summary, I completed the run in 2:01 hours. My goal was to finish within 2 hours, but I missed it by just one minute—no big deal. If I can maintain this pace, I might be able to finish the 42km in about 5 hours, or if I really push it, maybe even 4:30 hours. My final pace was 6:03/km, or 6:03 minutes per kilometer. It might be a bit high, but not bad for my first attempt.

Let’s do some quick math: if I maintain this 6-minute pace for 42km, it would take about 252 minutes, or roughly 4:20 hours. That would be an impressive finish if I can hold that pace!

I’m not even considering all the other factors I’ll have to deal with on race day. For now, I’m setting a goal of finishing in 5:00 hours. From here on out, it’s all about training, training, training—just one more week to go!