Much of the research on aging and endurance performance suggests that there are physiological and nutritional changes that start occurring between the ages of 35 and 40 years that may limit endurance performance. Several master athletes complain of weight gain, slowed recovery time, nagging injuries, and diminished performance. Yet, many master athletes continue to conquer the running scene, beating their younger counterparts. Look at 42 year-old Yekaterina Podkopayeva, a female Russian distance runner who ran 1500 meters in less than 4 minutes. Or marathoner Jack Foster who conquered 26.2 miles in 2:19 at the age of 41. As simple as it may sound, peak performance for all ages relies on 2 factors: smart training and proper nutrition.