Hmm, looks like that advice would work for Hammer's day-to-day purposes, now that he's had his Big Birthday, but it's more about insomnia than jet lag.
I saw a review of jet lag-related melatonin studies that concluded: "Daily doses of melatonin between 0.5 and 5mg are similarly effective [in adjusting to new time zone], except that people fall asleep faster and sleep better after 5mg than 0.5mg."
One study they reviewed found that 2 mg slow-release was ineffective, i.e. you're best to take a big hit at the start.
Both of our studies are 15 years old so I'll keep looking for something more recent. Here is something else I stumbled upon that talks about melatonin and endurance sport. Nutshell: There may be some effects but more research is needed.