I've been going to a gym near my house a lot, and each time I'm there, my heart rate goes up.
If you're one of the gazillion people around the world who have downloaded the Pokemon Go app, you'll know that, these days, a gym isn't a gym as we have always known it.
A gym is where you hang out so that your Pokemon monsters can fight other people's monsters.
There are two gyms near where I live. One is a waterfall feature at the entrance of a condominium, and the other is a church.
I've visited both and, after much frantic tapping on my phone, have managed to control the gyms on three or four occasions. (I'm in Team Mystic.)
I'm a novice at Pokemon Go. I'm only at level 16 and have caught just 60 Pokemon. My most powerful is Vaporeon with a CP (combat power) of 1,156.
My favourite Pokemon is Eevee because of its adorable Bambi-like face and flicking bushy tail. I detest Rattata, the snaggle-toothed rat that pops up everywhere I go.
My most thrilling Pokemon encounter? It was at the office. I was working at my desk late one night with my phone switched on to the app when I felt a vibration and saw a swish of blue at the edge of the screen.
Gyarados?! I couldn't believe my eyes, and it was one with a high CP of 977 too.
Pokemon sightings in the office have been limited to annoyingly common, low-grade critters like Magikarp, Psyduck and Pidgey. Gyarados is a much rarer Pokemon.
I wouldn't say my fingers were trembling, but I was excited and nervous. One Razz Berry and two Great Balls later, Gyarados was in my bag. It was a great feeling.
H plays Pokemon Go, too, and over the past three weekends, our idea of fun has been to go around looking for monsters.
We were at Millenia Walk one Sunday when, taking the escalator up to Harvey Norman, Dragonite appeared on his screen.
I was trailing behind him (heading to a PokeStop outside the building actually) and he beckoned to me. Alas, Dragonite - an elusive Pokemon - was nowhere to be found when I got there.
He seems to have better luck than me in catching 'em monsters.
One of his eggs hatched and out came the much-sought-after Snorlax. Then, when he was walking in Chinatown, another Snorlax appeared (with a CP of 1,634) and he managed to catch it. He also has two Pikachu.
We send each other screengrabs of the rarer Pokemon we snare. We compare our Pokedexes.
One night after dinner, we decided to walk to a chapel nearby, which is a PokeStop.
After collecting our Pokeballs, we placed a Lure and sat on the kerb to wait for the monsters to appear. But it was a pretty useless Lure as only a few Rattatas showed up.
But we had a nice time. It was rather romantic, sitting by the road in the dark, shoulder to shoulder, smartphones aglow.
Unless you have been living under a rock, you'd know that Pokemon Go is the latest fad.
It's not just in Singapore, but also around the world, with more than 100 million downloads of the game so far.
It started making headlines when it was launched in the United States, Australia and New Zealand last month.
It was finally available in Singapore on Aug 6 and the first two weekends were crazy. Everywhere you went, you saw people walking like zombies with their eyes trained on their phones.
There have been stories of Pokemon hunters making a nuisance of themselves in housing estates. Videos show amazing hordes of people camped out at playgrounds or dashing across roads en masse to hunt down rare Pokemon.
Shops have come up with promotions. At one nasi lemak chain, you get a discount on chicken wings if you show your Pidgeot or Pidgeotto.
Last weekend, 400 people gathered for an 8km walk from East Coast Park to Marina Barrage to hunt for Pokemon.
Pokemon Go was even mentioned at Prime Minister Lee Hsien Loong's National Day Rally.
The game has been addictive because it ticks all the right boxes.
Pokemon in its original versions - video game, trading cards, anime, comic books, merchandise - has been wildly popular since the 1990s, and so it already has a following.
The good thing about the game is you can play it at different levels.
Those who want depth can dive into each monster's complex history - species type, weight, height, stardust and candy requirements, fighting style, CP and HP (hit point).
Yet, the game is simple enough for a newcomer. There's no need to go deeper if you don't want to. Just lob some balls at the cute critters on your screen.
Players feel both anticipation and adventure. You don't know when or which monsters will suddenly appear. (I caught Scyther in my bathroom at home.)
There's real excitement when you spot a rare Pokemon because it is, well, rare, and because you don't know if it will allow itself to be captured.
The graphics and sound effects are brilliant and, the best part is, the game forces you to get out and walk. It's more effective than wearing a fitness tracker to get you to exercise. You even get to meet people (at Millenia Walk, we got to talking to a young tourist who was also Pokemon hunting).
The Pokemon Go craze will die, of course. Fatigue is already setting in.
Last week, it was reported that the number of daily active users, downloads, engagement and time spent on the app are well off their peaks and on a downward trend.
It's to be expected.
Fads come and go and they apply to anything from a food fad (salted-egg croissants) to a fashion fad (jogger pants) to just something that catches people's fancy (Gangnam Style) or even a cause (ice bucket challenge).
There is a finite period when it spreads like wildfire, attracting fanatical fans, inspiring spin-offs and hogging conversations.
Then, when the novelty wears off for users, when too much has been written about it or it fails to offer something new, interest falters.
It happened for me with another mobile game fad, Candy Crush.
For months, I lost sleep trying to smash virtual candy. My brain reeled with images of coloured jelly beans. After half a year, I got bored and just went off it. It's been ages since I played the game.
Before Candy Crush, there was my Furby mania and, going back further in time, Snake and Tamagotchi. (Yes, I'm a follower of fads, but what's wrong with having some mindless fun in life? )
Already, I see fewer Pokemon Go zombies and fewer people talking about the game. This is also the first weekend I haven't planned something around monster hunting.
That said, I'll still have my app switched on and will check it from time to time.
And if Snorlax should deign to pay me a visit, you can bet my last PokeCoin I'll go all out and catch it.
•Follow Sumiko Tan on Twitter @STsumikotan