Negative Split For Your Next Race

Still on Vince Mauri, he started fast at the Chicago marathon and then dropped a 14:28 min 5 km split (2:53 min/km or 4:39 min/mile) from 20-25 km. He was on course to run a 2:04 hrs race, enough to break the American record of 2:04:43 hrs. 

However he was running on his own in no man's land, behind the race leaders but in front of his fellow Americans, Clayton Young and Charles Hicks. Then Mauri faltered. He basically tried to bank in time early. Most runners know that the best way to approach a race is to run a negative split. A negative split means running the second half of the race faster than the first half.

Runners know that how you pace yourself at the start is critical in a race, especially in a marathon. If you ran like Mauri, you are doing a positive split, a faster first half of the race followed by a slower second half.

However a review of pacing physiology found negative splits improve glycogen sparing, thermoregulation and cardiovascular drift compared to a fast start. These benefits contribute to delayed fatigue (by sparing glycogen usage) and greater efficiency in the later parts of the race. 

If one wishes to race well in a marathon, you need to have enough muscle glycogen. Starting too fast in a race hastens the rate of glycogen breakdown and leads to fatigue inducing metabolites like lactate and hydrogen ions. A negative split pacing strategy allows for more gradual glycogen utilization (since you are going slower) and preserve energy for the later stages of the race.

When you start slower, a higher proportion of your energy are derived from using your fat stores, thus sparing glycogen stores. When glycogen stores are depleted, runners are forced to rely on slower, less efficient energy systems. You experience hypoglycemia-induced fatigue or "hitting the wall".

Glycogen sparing also helps sustain neuromuscular coordination and delay central and peripheral fatigue, both are essential for maintaining biomechanical efficiency in the later stages of a marathon.

This approach is consistenty associated with superior race outcomes (Sha et al, 2024). For example, Eliud Kipchoge's sub-2 hour marathon involved a highly controlled pace with subtle acceleration in the final stages, a textbook example of even to negative pacing.

Remember my post on warm weather making me eat more during my 3 hour Saturday rides? Starting at a conservative pace reduces metabolic heat generation during the early stages as well. Thermoregulation plays a vital role in endurance performance especially in a marathon where progressive effort leads to progressive heat accumulation. 

When core temperature rises, the central nervous system initiates protective mechanisms to limit further exertions, known as "central fatigue". A negative split strategy allows for a more controlled rate of heat production early on, helping to delay the onset of thermally induced fatigue.

Moreover, better thermoregulation helps to improve cardiovascular stability. In hot conditions, blood supply is partly directed to the skin for cooling purposes. Meaning your running muscles may not get as much blood flow.

As you sweat more, your blood volume drops causing your heart to beat faster just to maintain cardiac output (or cardiovascular drift). A conservative start minimizes early sweat loss, preserving your blood volume for the final push.

How do you execute a negative split for your race? The authors suggest doing progressive long runs to simulate negative split pacing. Begin at easy pace and gradually increase to race pace or faster in the closing kilometers allowing you to practice the metabolic and mental transition from conservative to assertive effort. Other strategies include tempo runs with a fast finish, negative split intervals and controlled progression runs to develop pacing control and late race strength.

Perhaps using heart rate monitors, GPS pacing, etc is necessary for some runners to achieve pacing awareness.

To run a negative split, you need to have confidence, patience and a tolerance for initial 'underperformance'. You need to resist temptation to "bank time" early and trust your ability to finish strong. 

You can practise visualization, goal setting and self-talk to help reinforce a conservative start and maintain focus before the crucial end part of the race.

Reference

Grivas GV. The Physiology And Psychology Of Negative Splits: Insights Into Optimal Marathon Pacing Strategies. Frint Physiol. 16: 1639816. DOI: 10.3389/fphys. 2025.1639816

Lane 8 Distance On A Track

Picture from SacKenny

I probably would never run as long and as fast as Vinny Mauri on a treadmill. The longest I've ran on a treadmill is probably slightly more than an hour in Birmingham, UK. This was when it was windy and rainy outside. I was traveling with the Singapore Badminton team then. They were taking part in the All England Open Badminton Championships.

I did run many laps at the old National Stadium where I worked previously. I would also run on the grass outside lane 8 of the track to cover more ground. 

I never really knew the exact distance for every lap I did. I just 'guesstimated' the distance when I recorded it in my training log book. 

I just saw the above picture of the distance you cover depending on which lane you run in. So if you need to run many laps on a track, see the exact distance in the picture above.

Give Him A Treadmill

Mauri after his debut marathon in Toledo

I had a patient who told me that while training the marathon segment of the Ironman triathlon event, she would often go to the old Kallang Practice Track and and run 50 rounds (20 km). She could focus on running and not have to worry about traffic lights, pedestrians or spraining her ankle on an uneven pavement.

Meet Vinny Mauri, who ran a 2:05:54 hrs in his marathon debut in April this year at the unheralded Glass City marathon in Toledo. The race had less than 1,300 finishers, no pacers and a previous course record of 2:19:31 hrs. 

He also does most of his training on a Planet Fitness treadmill. 6 months ago, 25 year old Mauri was largely unknown. However, at the Chicago marathon next week (11/10/26), he has a good chance of breaking the American record of 2:04:43 hrs set by Connor Mantz at the same race last year.

Mauri has what many consider an abnormal training routine. He runs the majority of his miles on treadmills at one of two Planet Fitness gyms near his hometown of Warren in Northeast Ohio.

He rarely runs slower than 6:00 min /mile (or 3:44 min/km) for any of his runs. He regularly reaches 30 miles (48 km) at under 5:00 min/mile (or 3:06 min/km) pace.

He runs very little in carbon plated shoes. In fact he only just signed a shoe contract with Asics last week. He does all that while working more than 15 hours a week at a running store. 

On June 28th this year, he earned 611 kudos after his effort on Strava post went viral for running 26.39 miles (42.7 km) on a Planet Fitness treadmill in 2:20 hrs. Impressed?

Only a week later, he ran 29.16 miles (46.66 km) even faster at 2:15 hrs marathon pace again on a treadmill. Or 5:09 min per mile (3:20 min/km).

He clocked a total of 1,223 miles (1957 km) in his last 10 weeks of training. All at an average pace of 5:38 per mile (3:30 min/km).

If you look at Conner Mantz's same 10 week training block leading up to his American record of 2:04:43 hrs set in Chicago last year, Mantz ran 1,182 miles (1891 km). His average pace of 6:35 min/mile (4:05 min/km) was almost a minute a mile slower than Mauri's.

For 4 straight Tuesdays from 25th August to September 15th, Mauri ran 4 godzilla sets of double workouts. On each of those Tuesdays, he ran 36 miles, with at least 27 of those miles at 4:56 min/mile (3:04 min/km) pace or faster. 

On 8th Septemeber, he ran 36 miles at an average pace of 4:56 min/mile (3:04 min/km). 2x50 minutes in the morning, 4x20 mins in the afternoon. That's 36 miles at 2:09:09 marathon pace. If you include his warm up and cool down runs, he logged 45 miles (72 km) that day (pictured below). 

If you include his 28 miles long run and a 13 miles "easy" run at 6:00 min/ mile (3:44 min/km) pace across the previous days from 6th-8th September, Mauri ran 86 miles in 3 days at an average of 5:27 min/mile (3:23 min/km).

He ran the fastest debut marathon in American history on a day the marathon world was watching Sabastian Sawe break 2 hours in London. In one race, he went from being a virtual unknown to 4th fastest of all time on the US marathon list.

Why does he run so much on a treadmill? Perfect weather, no need to worry about wind, snow or ice in winter or heat/ humidity in summer. He likes the convenience, gels and drinks always at hand and the bathroom is nearby if needed.

He also runs on a treadmill to protect himself as he has a natural tendency to pick up the pace during runs outside. In a 60 min recovery run outdoors recently, he wanted to run a 6:10 mile/min (or 3:55min/km), he averaged 5:25 min/mile (3:22 min/km) and was running sub-5:00 min/mile (3:00 min/km) at the end.

The Planet Fitness treadmills stop automatically after an hour, and Mauri has to stop and start the machine again once or twice per session, usually during his rest periods. The treadmills also max out at 12.4 miles/hour (20km/hr) or 4:50 min/ mile (3:00 min/km), meaning he cannot go faster than that, thus holding him back to prevent going too fast. That's slower than his marathon race in Toledo 2:05:54 hrs which is 4:48min/ mile (2:59 min/km).

Can he beat the US record next week? You can get good training on a treadmill, but it does not quite equal to racing outdoors. The race in Chicago next week will require one to know which moves to respond to when the pack goes out too fast or slow and how to adjust to the temperature and wind etc.

Mauri says he feel's fitter than before his race in Toledo. His entire buildup is documented on Strava (pictured above), yet so unorthodox, and does not include tune up races.

I don't know how it will translate to the streets of Chicago. Everything about Mauri's build up to Chicago is superior to Toledo. Longer buildup, significantly more miles at a much faster pace. He will also be racing against a stacked field.

I will definitely be cheering him on. The treadmill companies should give him a faster treadmill (than his race pace) to train at home.

PS *Mauri finished the race 10th overall and 3rd American in 2:06:45 hrs. He ran a 14:28 min 5 km split (2:53 min/km or 4:39 min/mile) from 20-25 km, on course for a 2:04 hrs pace. Alas, the oppressive humidity came back to bite him as he had to stop and stretch his hamstrings twice. 

Even though he was reeled in by Clayton Young, Charles Hicks and Japan's Akira Akasaki, he stayed at or near the front of that group as long as he could. Young would finish 7th overall in 2:05:23 hrs as the first American, Hicks was the 2nd american and 8th overall in 2:05:35 hrs, just 12 seconds behind Young.

Mauri is definitely not a one hit wonder.