Applied Exercise Science Lab is seeking 18-35 year old male and female recreationally active noncyclists who exercise for ≥3 sessions/wk for >30 min (2.5–5 hrs/wk) consisting of noncycling aerobic exercise. Also seeking 18-35 year old female UCI ranked cyclists training >8 hrs/wk. Additional screening questions will be asked upon inquiry. Study requires 8 hrs: 4 visits, 2 hrs/visit. You will be compensated $50 for participating. Assessment of VO2max, lactate threshold, efficiency and training zone break downs provided.