Santo Domingo, the first street the bulls encounter after leaving the corrals, is the steepest and most physically demanding section of the encierro route. The street rises at an incline of 10 to 15 degrees, which creates a dramatically different running environment than the flatter sections that follow. For a runner, 10 to 15 degrees of incline at full sprint is physiologically demanding. For a bull with four legs and a low center of gravity, the incline provides traction and confidence. The speed differential between bulls and humans is greater on Santo Domingo than anywhere else on the route, which is one reason that Dennis does not recommend Santo Domingo for first-time runners. The physics of the incline, combined with the height of the stone walls on either side and the atmosphere of the opening moments of the encierro, make Santo Domingo a section that requires specific knowledge and understanding. Understanding the physics of the incline helps runners understand why this section demands a particular approach.
The Grade of the Incline: 10 to 15 Degrees
The actual measurement of Santo Domingo’s incline is specific and significant. Dennis provides this detail:
“The incline measures at 10 to 15 degrees, which is quite significant when trying to run at full speed.”
Dennis Clancey, Founder of Encierro and member of La Única Peña
To understand what this means, consider that a typical hiking trail considered steep is about 15 to 20 degrees. A road grade that cars struggle with is 10 to 12 degrees. Santo Domingo’s 10 to 15-degree incline puts it in the range of very steep terrain. For a human attempting to run uphill at maximum effort, the incline is immediately demanding. The muscles fatigue differently. The breathing is harder. The biomechanics of running change.
According to Mat Dowsett in “Encierro!” (2003), Santo Domingo is not cobbled in its lower sections but has a rough coating. The upper portion of Santo Domingo has a white band that runs along the edges on both sides, marking the raised pavement that guides drainage. This white band, as Dennis notes, is particularly relevant to understanding the footing on the incline.
Bull Speed Advantage on the Incline
The incline favors the bulls significantly. While bulls are generally slower on Estafeta due to crowd density and the length of that street, on Santo Domingo the speed advantage is dramatic. Dennis explains the physics:
“The bulls are disproportionately even faster than humans than on a normal, straight no-slope terrain. The bulls have confidence going uphill.”
Dennis Clancey, Founder of Encierro and member of La Única Peña
This is a critical observation. A bull’s four-leg structure, low center of gravity, and weight distribution give it significant advantages going uphill. The incline that slows a human runner actually increases the bull’s relative speed advantage. The bulls are disproportionately faster on the incline than they would be on flat ground.
The psychological element is also important. According to Dennis, the bulls have confidence going uphill. They are not struggling. They are moving with purpose and power. A runner watching a herd of bulls accelerate uphill with confidence is witnessing the reason Santo Domingo is not for first-timers.
The Speed Differential: Five or Six Paces in One Second
Dennis quantifies the speed advantage in practical terms:
“They can close five, six paces within a second. You typically see runners who are darting out of the way rather quickly as the bulls close on them.”
Dennis Clancey, Founder of Encierro and member of La Única Peña
This means that if you are running uphill on Santo Domingo and the bulls are 5 to 6 paces (roughly 7.5 to 9 meters) behind you, the bulls will be at your position within one second. This is effectively instantaneous. There is no margin for error. You are not racing the bulls on Santo Domingo; you are being overtaken by them.
The fact that “runners are darting out of the way rather quickly” reveals the typical running style on Santo Domingo. Runners do not attempt to run up Santo Domingo alongside the bulls for an extended distance. They dart, move, react. The incline and the speed make sustained running impossible for most participants.
The White Band Hazard and Footing
The white band that runs along both sides of upper Santo Domingo presents a specific hazard. Dennis identifies this:
“Towards the upper part of Santo Domingo, there’s a white band that runs in the direction of the run on either side that can be quite slippery.”
Dennis Clancey, Founder of Encierro and member of La Única Peña
This white band, which Dowsett documents in “Encierro!” (2003), is part of the old raised pavement system designed for drainage. It runs lengthwise along both sides of the street. When wet, it becomes slippery. People fall regularly on these white bands.
Dennis recommends a practical approach to assessing this footing:
“Before the run, you can run your shoes against them, and you’ll see how slippery they are.”
Dennis Clancey, Founder of Encierro and member of La Única Peña
This is actionable advice. A runner arriving early on the morning of the encierro, standing on Santo Domingo before 8:00 am, can test their footing by running their shoes along the white band to feel the traction. If the band is slippery, the runner gains valuable information: staying away from the white bands becomes a positioning consideration.
Running Style: Reactive Rather Than Sustained
The physics of Santo Domingo creates a particular running style. Dennis contrasts Santo Domingo with later sections of the route:
“It’s really later portions of the run route where you can see runners getting closer right in front of the horns. You typically don’t see that in Santo Domingo.”
Dennis Clancey, Founder of Encierro and member of La Única Peña
This observation is significant. On Estafeta and other flatter sections, experienced runners can run directly in front of the bulls, maintaining position and distance. This kind of sustained running is possible because the geometry and incline do not create the extreme speed differential that Santo Domingo does. On Santo Domingo, runners dart and react. They do not maintain position.
This distinction is one reason that Dennis recommends first-time runners avoid Santo Domingo entirely. The running style required is reactive, not contemplative. There is no time to process what is happening or to make strategic decisions. The speed and physics of the incline eliminate the margin for error that spatial awareness and good positioning provide elsewhere on the route.
Santo Domingo’s Historical and Structural Significance
According to Mat Dowsett in “Encierro!” (2003), Santo Domingo is the oldest section of the encierro route, dating back to the 14th century. The street was chosen for the herding of bulls because its incline naturally slows the herd and makes them more manageable as they enter the city. The incline was a feature, not a bug, in the original design of the route.
But the incline that makes the bulls more manageable for the pastores makes Santo Domingo more dangerous for runners. The same physics that gives the bulls confidence and traction gives them a disproportionate speed advantage over running humans. The incline does not slow the bulls nearly as much as it would slow a human athlete.
Acoustic Environment and Sensory Overload on Santo Domingo
According to Mat Dowsett in “Encierro!” (2003), Santo Domingo is bordered by tall stone walls on the right and left sides. These walls create an acoustic tunnel effect. The pounding of hooves on stone echoes off the walls. The sounds of spectators, runners, and pastores reverberate. The acoustic environment on Santo Domingo is intense and can be disorienting.
For a first-time runner trying to develop spatial awareness, this acoustic overload combined with the physical demands of the incline and the extreme speed makes Santo Domingo an impossible place to think clearly. Processing sensory input requires time, and Santo Domingo offers no time.
Dennis’s Encierro Philosophy Applied to Santo Domingo
The encierro preparation philosophy emphasizes putting runners in places where they can process what is happening. Dennis does not recommend Santo Domingo for first-timers because this section does not allow processing. The speed, the incline, the acoustic environment, and the footing all combine to eliminate the space for spatial awareness to develop.
A first-time runner who follows Dennis’s advice avoids Santo Domingo and enters the route on Mercaderes or Estafeta. This allows them to see the herd while it is already in motion, already slowed slightly by the plaza and the crowds of Mercaderes. The first run becomes about learning and observation, not about attempting to run Santo Domingo with the bulls at their fastest.
Training on the Incline: What the Science Reveals
The incline of Santo Domingo affects human physiology in measurable ways. Running uphill at full sprint depletes muscles of oxygen and energy significantly faster than running on flat ground. The biomechanics of uphill running mean that each stride is less efficient. Heart rate elevates faster. Lactic acid buildup increases. For a runner fresh at 8:00 am but fatigued by the uphill exertion, the ability to react and make decisions is compromised.
This is why experienced runners who do choose to run Santo Domingo typically position themselves further down the street where the incline is less severe, or they commit to specific, pre-planned movements that do not require real-time decision-making during the run.
Vocabulario: Spanish Terms Related to Santo Domingo and Incline
Cuesta de Santo Domingo (CWES-tah deh SAHN-toh doh-MEEN-goh): The incline of Santo Domingo; the hill or slope.
Incline (in-CLEE-neh): The slope or grade of the street. Santo Domingo’s 10-15 degree incline is steep.
Pastor (pahs-TOR): A herder who manages the bulls. The pastores on Santo Domingo manage the speed and direction of the herd as it moves uphill.
Suelto (SWEL-toh): A separated bull. A suelto on Santo Domingo is particularly dangerous because of the speed and the difficulty of escaping on the incline.
Frequently Asked Questions
Should first-time runners attempt Santo Domingo?
No. Dennis recommends that first-time runners avoid Santo Domingo. The 10-15 degree incline, the extreme speed differential, the acoustic environment, and the slippery footing combine to make this section unsuitable for learning and developing spatial awareness. First-time runners should enter the route on Mercaderes or Estafeta and allow their first run to be about observation and learning.
How fast are the bulls on Santo Domingo?
The bulls maintain their remarkable speed on Santo Domingo despite the incline. In fact, their speed advantage over human runners is even greater on the incline than on flat ground. The bulls can close 5 to 6 paces (7.5 to 9 meters) in one second, leaving almost no margin for error.
What is the white band on Santo Domingo, and why does it matter?
The white band is a raised pavement that runs along both sides of upper Santo Domingo for drainage purposes. When wet, it becomes slippery and is a common cause of falls. Testing your footing on the white band before the run can help you decide whether to avoid it or adjust your positioning based on the traction available.
Why is the acoustic environment on Santo Domingo so intense?
Santo Domingo is bordered by tall stone walls on both sides. These walls create an acoustic tunnel effect that amplifies sounds: hooves, voices, breathing, and the general noise of the encierro all echo and reverberate. For someone trying to maintain spatial awareness, this acoustic overload is challenging.
Respect the Physics of Santo Domingo
Santo Domingo is a fundamental part of the encierro, but it is not a place where first-time runners develop their spatial awareness and positioning skills. Understanding the physics of the incline, the speed advantage of the bulls, and the demands of the section helps runners make smart decisions about where and how to run. Our preparation sessions explain Santo Domingo in detail and help you understand why first-time runners should position themselves elsewhere. Study the full route, or book a tour with Encierro and stand on Santo Domingo yourself to feel the incline and understand the physics that govern this section of the run.