According to the search results, a 2-hour marathon pace is 4 minutes and 34.6 seconds per mile or 2 minutes and 50 seconds per kilometer. This pace requires a runner to maintain an average speed of 21.1 kilometers per hour (13.1 miles per hour) . It is worth noting that this pace is extremely fast and requires a high level of physical fitness and training to achieve. In fact, according to a study published in the Journal of Applied Physiology, a 59-kilogram (130-pound) runner would need to take in about four liters of oxygen per minute to maintain a two-hour marathon pace.