Not an ideal start time when running in a tropical and humid country. Searching for the start was probably the most confusing part of this route but once you get onto the Changi Airport Connector, it is smooth sailing from there on. Got totally distracted with the dinosaurs along Jurrasic Mile - one of the many free attractions in Singapore. The route posted started from Terminal 4 but I started at Terminal 2 (follow the signs to Hub & Spoke and then follow the red path) just a couple kms before as it was the official start/end point of the Changi Airport Connector.
Did this route unsupported - plenty of restrooms along East Coast Park. I assumed all tap water in Singapore is safe for drinking. Tummy didn't feel too good at the end but that could be due to starting with an empty stomach or... Dirty restroom tap water? I would advise to bring a water flask along with you - there's water fountains too but you're not allowed to drink straight from them (due to Covid) so you'll have to fill up as you go. There's also Maccas and Starbucks along East Coast Park so as long as you have money on you, you're good.