Guinea pigs can run at speeds of about 35 miles per hour. However, this speed is rarely seen in a domestic setting, as most guinea pigs are quite content to explore their surroundings at a much slower pace.
Guinea pigs are not built for long-distance running like some animals; instead, they are more agile and can make quick bursts of speed when needed. Their short legs and rounded bodies are designed for stability rather than speed, allowing them to navigate through grass and brush where they would naturally seek shelter from predators.
In a typical home environment, you may notice your guinea pig running around excitedly during playtime, but this is usually at a more moderate pace. Providing them with space to roam and things to explore will encourage their natural behavior and allow them to get some exercise in a safe and happy way.