Complex sentence: He began training for the Olympic Games in Athens, at first struggling with illness and fitness, he arrived in peak form; he qualified for the individual pursuit with a time of four minutes and 15.165 seconds, an Olympic record and fifth fastest time in history.
Split into simpler sentences: He began training for the Olympic Games in Athens, at first struggling with illness and fitness, he arrived in peak form. At the Olympics he qualified for the individual pursuit with a time of four minutes and 15.165 seconds, an Olympic record and fifth fastest time in history.