Dogs vary a lot in how much energy they use, both at rest and during activity. Different breeds are built for different kinds of work, so they don’t all use energy the same way. Scientists measure this with calorimetry, which is the standard method for tracking how much energy a body actually burns. Sighthounds are built for sprinting, not for constant movement or long-distance running like huskies. Sled dogs are designed to burn steady energy over many hours. Sighthounds are designed to use a large amount of energy in a very short time. ''The study compared anaerobic (sprinting) exercise in Greyhounds with aerobic (endurance) exercise in sled dogs. Greyhounds were run ~400 m (sprinting) and blood samples were taken before and after exercise. Sled dogs ran 3.5–5 hours per day over several days. Greyhounds showed no major change in leptin or adiponectin after sprint exercise, but a rise in irisin shortly after sprinting. Sled dogs showed changes in leptin related to endurance activity. Sprinting and endurance exercise affect physiology differently.'' Sprinting Greyhounds produce metabolic responses consistent with short, intense effort, while endurance dogs show different energetic effects. They evolved to chase prey with extreme speed over short bursts. When they start running, they accelerate fast and use a lot of power at once. That’s why they don’t spend the whole day moving — their bodies keep energy in reserve. So when you see a sighthound resting for hours, that isn’t laziness. It’s conservation. They stay in a low-energy state so they are always physically prepared for intense effort when it matters. For example a Greyhound that ran hard for an hour would not have the same explosive capacity left for a sudden chase later. Their physiology protects that burst ability. They can sleep most of the day and still produce incredible speed when needed. That makes sighthounds efficient at rest and powerful in motion. Sighthounds Are Not Just Couch Potatoes

Sighthounds are dogs built for one main purpose: hunting fast prey using sight and speed. Breeds like the Greyhound, Saluki, Borzoi, Afghan Hound, and others may look very similar at first glance—but modern genetic research shows they did not all come from the same place. This article (Source at the end) explains what scientists discovered about where sighthounds came from, how they evolved, and why they look so alike despite having different genetic backgrounds. Why Sighthounds Are Special? Most modern dog breeds were standardized in the 19th century, but many sighthounds are much older. Some existed long before kennel clubs or written breed standards. Because historical records are limited, scientists use genomics to uncover their origins. Researchers analyzed the genomes of: - 123 sighthounds from Africa, Europe, Russia, Central Asia, the Middle East, and China - Village dogs from the Middle East - Modern wolves and ancient wolves The results showed that sighthounds do not share a single origin. - Sighthounds were bred independently in different regions - Major lineages formed in Africa, Europe, and the Middle East/Central Asia - These groups cluster genetically with local village dogs, not with each other Means people in different parts of the world created similar dogs on their own, driven by the same hunting needs. So Why Do They All Look the Same? Even though they come from different genetic backgrounds, sighthounds share key traits: - Deep chest - Long, slim limbs - Lean body - Sharp eyesight This is explained by convergent selection: - Different genes were selected in different regions; those genes affected the same biological systems, such as: - Heart and blood circulation - Muscle performance - Limb development This study supports ; Humans in different regions repeatedly bred dogs for the same purpose—and evolution found similar solutions each time. Sighthounds are not the result of one origin, but of many cultures selecting for speed, vision, and hunting ability.

I made a long research about why sighthounds look uncomfortable while sitting...Here's what I found. Sighthounds are often observed sitting in ways that look awkward to us — legs splayed out, “hover-butt” postures, or quick shifts from sit to lie. While this can catch the eye of owners, biomechanical research suggests this is entirely normal for healthy Greyhounds and reflects their highly specialized anatomy. 1. Anatomical Specialization for Speed Greyhounds are extreme athletes, bred for sprinting and high-speed locomotion. Their skeletal and muscular structures reflect this specialization: - Long, slender limbs maximize stride length and speed. - A narrow pelvis and highly flexible spine allow extreme spinal extension during gallop. - Long distal tendons with short muscle fibers in the hindlimbs favor elastic energy storage and rapid limb propulsion. These traits are excellent for sprinting, but they create mechanical disadvantages for postures that require deep joint flexion, such as a textbook sit. The alignment of the pelvis and hindlimbs, optimized for forward propulsion, makes deep hip flexion and compact sitting less efficient. 2. Sit-to-Stand (StS) Biomechanics Although no study directly quantifies static sitting comfort in Sighthounds the Sit-to-Stand (StS) movement provides important insight into why sitting and rising can be demanding. In a detailed biomechanical study (Ellis et al., 2018), researchers measured: - Joint kinematics and limb forces - Muscle fiber forces, activations, and length changesduring the transition from a crouched sit to standing. Key findings: - Hindlimb joints move through near-maximal ranges of motion. - Anti-gravity muscles begin in highly stretched positions and undergo length changes of ≈50%. - Muscle leverage in the crouched position is suboptimal, requiring heavy reliance on passive structures such as tendons and ligaments. These results show that even a healthy Greyhound must recruit large amounts of muscular and passive support to rise from a sit. The biomechanics of standing up are therefore inherently demanding for a breed shaped for speed rather than static postures.

Roaching is when a sighthound lies on their back, legs in the air — basically sleeping upside down. Why do they roach? 1. Sighthounds often roach because it allows a full release of the back and abdominal muscles, decompression of the spine, and relief of tension. It may look weird, but their flexible spine and long lumbar section make this position very comfortable for them. Roaching also helps with body temperature regulation. 2. Roaching happens only when a dog feels safe. (I’ve also heard that cats allow belly touching only when they fully trust you 🙂.) A dog won’t expose its weakest points — the belly and neck — if it feels threatened in any way. Roaching means the dog is relaxed, feels safe, and is comfortable in its environment. Guardian and herding breeds whose job involves watching flocks never sleep on their backs. They manage to doze with one eye open in case they have to jump up in a hurry. Form follows function even in sleeping. Some bloodlines roach more than others. Roaching should not be interpreted as pain, “being broken,” or something being wrong. They love sleeping in this comfy, unique roach position. ''The only danger of a dog asleep on its back is slipping and falling off a bed because it feels so relaxed.'' Explains Mr. Klein Source: Academic study on dog behavior and postures, American Kennel Club explanation of why dogs sleep on their backs