Houston Marathon Fueling Plan & Pace Chart

Houston Fueling Strategy

Houston is the flattest major marathon in the United States and that is exactly what makes it easy to under-fuel. There are 225 feet of climbing across 26.2 miles, more than 92 percent of the course is graded flat, and the only real hill is a hundred-yard overpass at mile 12.7. Nothing about the terrain will ever change your rhythm, and nothing will ever remind you to eat. On Boston or Marine Corps the course itself tells you where you are in the race. Houston does not. Set watch alarms before the gun and run the fueling plan off the clock, because you will not feel the miles go by.

The on-course drink does real work here, which is unusual and worth planning around. Houston serves Gatorade Endurance Formula in Lemon-Lime at sixteen refueling stations spaced every 1.5 miles from mile 2, which is the densest fluid support of any major American marathon. Gatorade Endurance carries 22 grams of carbohydrate and 310 milligrams of sodium per 12 ounces. A race cup filled to four to six ounces is worth roughly 7 to 11 grams of carbohydrate and 103 to 155 milligrams of sodium. If you actually drain a full cup at all sixteen stations you are looking at something like 120 to 175 grams of carbohydrate across the race, which is 35 to 50 grams an hour at a 3:30 finish. Most runners get maybe two thirds of that down, so budget 20 to 30 grams an hour from the drink and treat anything more as a bonus. That is a genuine contribution and you should count it, but count it honestly.

The gels are the opposite story. There are only two GU stations on the entire course, at mile 7 on Bissonnet near Mandell and at mile 18 on Memorial Drive west of Loop 610. That is an eleven-mile gap through the middle of the race and nothing at all in the final 8.2 miles. Carry every gel you intend to take. The GU on offer is the original formula, 21 to 23 grams of carbohydrate and 60 to 125 milligrams of sodium depending on flavor, and the flavor is not published in advance, so the caffeine could be anywhere from zero to 40 milligrams. If you are managing caffeine timing, do not leave it to a volunteer's hand at mile 18.

The first 7.6 miles are shared with roughly thirty thousand half marathoners and they are the fastest-feeling miles you will run all day. The gun goes at 6:55 a.m. before sunrise, the downtown skyline is lit, the streets are wide, and the crowd is pulling you along at a pace you did not choose. The course runs northwest onto the Washington Avenue corridor by mile 2, dips about nine feet crossing the Buffalo Bayou corridor near Studemont at mile 3, then climbs back out into River Oaks. Take your first gel at mile 3 and wash it down at the 3.5 station in River Oaks. It will feel early. Do it anyway, because the crowd energy through here reliably costs people fifteen to twenty seconds a mile they did not intend to spend, and that debt is paid out of glycogen.

The half marathoners peel off at 7.6 and the race goes quiet. There is a GU station at mile 7 immediately before the split, which is well placed: take one there whether or not you need it yet. Miles 7.6 through 15 run through the Museum District, past Rice University and Hermann Park, into West University Place, and then west toward the Galleria. It is pleasant, shaded, flat, and completely unremarkable, which is why it is the single most common place to lose the plot. Stations come at 8, 9.5, 11, 12.5 and 14. Use the 12.5 station at Westpark and Weslayan, because the overpass is next.

The US-59 overpass at mile 12.67 gains 25 feet in a tenth of a mile at a 4.7 percent grade and gives all of it back immediately on the far side. It is the only climb on the course and it is over in about forty seconds. Do not eat on it and do not try to race it. Fuel at 12.5 before you go up or at the mile 14 station on the feeder road after you come down. If you are running 75 to 90 grams of carbohydrate an hour you should have three to four gels in you by the time you crest it, plus whatever the Gatorade has contributed.

Miles 18 through 23 on Memorial Drive are where this race is decided. The course turns east and runs straight, exposed and largely unshaded for five miles. There is live music for about three of them and the Memorial Park Land Bridge tunnels at 20.5 have a DJ and a light show, but the road itself never changes direction and never changes grade. Under-fueled runners come apart here and there is no terrain to blame it on. Take the mile 18 GU station or your own gel at 18, then again around 21, using the stations at 18.5, 20 and 21.5 to wash them down. Use the half marathon marker as your audit point: at 13.1 you should have four gels in and be roughly on pace for your hourly target, and if you are behind, miles 14 through 18 are flat and quiet and are your last comfortable chance to catch up.

The last three miles are the only place Houston has any shape to it. The course turns onto Allen Parkway at mile 23 and drops to its lowest point of 23 feet at about mile 23.8, with the steepest descent on the course at mile 24. Then it rolls along Buffalo Bayou Park and climbs roughly twelve feet back up into the downtown grid across miles 25 and 26. Those rollers are trivial on paper and they are not trivial on legs that have run twenty-four flat miles at a single cadence. Take your final gel by mile 22 or 23 from your own supply, because there is no gel station after 18, and use the 23 and 24.5 stations for fluid only.

Weather is the one genuine variable at Houston and it swings hard. The fifteen-year race-day average is a 45 degree start with 74 percent humidity and a north wind around 9 miles an hour, but starts have ranged from 30 degrees in 2025 to 65 degrees with 99 percent humidity in 2017, and 2023 went off at 58 degrees and reached 72. Rain is rare, roughly one year in nine. In a cold year, and cold is the more likely outcome, run the top of the 75 to 90 gram range because gut absorption is better in the cold, and pre-tear your gel tabs before the gun since a 6:55 a.m. start in the 30s means numb fingers for the first hour. In a warm year the humidity is the problem rather than the temperature, because a high dew point shuts down evaporative cooling and your core temperature climbs even at a modest air temperature. Above 60 degrees at the start, raise fluid intake 15 to 20 percent, shift a larger share of your carbohydrate to the Gatorade rather than gels, and take advantage of the fact that stations come every 1.5 miles. Houston gives you more chances to drink than almost any course in the country. On a humid year, take them.