Last year's Chevron Houston Marathon came down to just a 37 second difference between first place finisher Bazu Worku and Ethiopian countryman Yitayal Atnafu, out of a pool of 7,185 runners. No surprise there as the pair trained together and it was Atnafu's third year in a row to secure the No. 2 spot. But there's so much more to know.

5. Everybody Has a Different Goal

From first-timers to middle-of-the-packers to elite runners, it's always a numbers game for the participants of the Chevron Houston Marathon, Aramco Houston Half Marathon and We Are Houston 5K. So what does it take to go the distance? A couch potato adding a marathon to his or her bucket list would need to train for about a year; four to six months for those who already can run a 10K, and about three to four months for somebody who's a fit, trained athlete.

For the cream of the crop, there are all sorts of targets. Some just want to beat a personal best while others are trying to rewrite the record books. Last year, two-time Olympian Molly Huddle broke the record for fastest half-marathon by an American woman, with a 1:07:25 finish. Many elites are trying to qualify for the Boston Marathon, a prestigious race that puts a notable notch in a serious runner's belt. The Atlanta Track Club is hosting the 2020 Olympic Trials Marathon, selecting the team for the 2020 Summer Olympics in Tokyo, but Houston — with its fast, flat course — has had the honor on more than a few occasions.

4. Hoopla Matters

Fan support, in the form of creative signage, wacky costumes and big name appearances, makes a big difference. Pounding the pavement for 13.1 or 26.2 miles can get monotonous and — in between the inevitable head games evaluating how much road lies behind or ahead — these sidewalk distractions are a welcome relief. A tip of the hat to the late President George H. W. Bush, a longtime supporter in front of St. Martin's Episcopal Church (near the 16 mile marker), who shook the hand of more than a few runners over the years.

3. One Man's Trash is Another Man's Treasure

With a January race, the weather is often chilly, even in Houston. But start running and those extra layers soon become a burden, which is why the course is often littered with cast off clothing. The Houston Marathon Committee has made a commitment to sustainability, and one of its green initiatives is to donate all discarded clothing to local homeless shelters.

2. Water Bottles Are So Last Week

Other green initiatives include a ban on Styrofoam, paperless registration for race participants and volunteers, virtual goodie bags (turning swag into e-swag) and reducing the need for plastic bottles by using filtered water from fire hydrants at all course water stations.

1. Marathon is More Than a Weekend

Marathon-related events actually begin on Thursday, with a Shake Out Run at Memorial Park. Friday brings a Health & Fitness EXPO at George R. Brown Convention Center, followed by a '90s-themed kickoff party at the House of Blues. The We Are Houston 5K is Saturday, more time at the EXPO and — just like Wayne and Garth — a chance to party on at Discovery Green with RunFest presented by Michelob Ultra. In addition to Sunday's big marathon and half marathon, RunFest continues until 2 p.m., along with the Charity and Running Club Village that's open to spectators with visits by members of the Houston Astros, Dynamo, Rockets and Texans.

The Chevron Houston Marathon and Aramco Houston Half Marathon are scheduled for Sunday, January 20, 2019, with 6:50 a.m. and 7:01 a.m. starts. For more information about the race and road closures, visit chevronhoustonmarathon.com.