This study examined physiological and race-pace characteristics of medium-level (finish time < 240 min) and low-level (finish time > 240 min) recreational runners who participated in a challenging marathon route with rolling hills, the Athens Authentic Marathon. Fifteen athletes (age 42 ± 7 years) performed an incremental test three to nine days before the 2018 Athens Marathon to determine maximal oxygen uptake (VO2max), maximal aerobic velocity (MAV), energy cost of running (ECr), and lactate-threshold velocity (vLTh), and their pacing during the race was analyzed. Medium-level runners (n = 8), compared with low-level runners (n = 7), had higher VO2max (55.6 ± 3.6 vs. 48.9 ± 4.8 mL·kg-1·min-1), MAV (16.5 ± 0.7 vs. 14.4 ± 1.2 km·h-1), and vLTh (11.6 ± 0.8 vs. 9.2 ± 0.7 km·h-1), and lower ECr at 10 km/h (1.137 ± 0.096 vs. 1.232 ± 0.068 kcal·kg-1·km-1; p < 0.05). Medium-level runners ran the marathon at a higher percentage of vLTh (105.1 ± 4.7 vs. 93.8 ± 6.2%) and VO2max (79.7 ± 7.7 vs. 68.8 ± 5.7%). Low-level runners ran at a lower percentage of their vLTh in the 21.1-30 km and 30-42.195 km splits (p < 0.05). Medium-level runners are less affected in their pacing than low-level runners during a marathon route with rolling hills. This could be due to superior physiological characteristics such as VO2max, ECr, vLTh, and fractional utilization of VO2max. A marathon race-pace strategy should be selected individually according to each athlete's level.