Vol. 7, Issue 1, Part B (2025)

This case report examines the impact of a change in exercise routine and environmental conditions on a client's VO2 max. The client transitioned from resistance training to a high-volume walking regimen in a hot, humid Middle Eastern climate. Contrary to expectations, this shift resulted in a decrease in VO2 max, measured using a Garmin Fenix wearable device, from 43 to 38 mL/kg/min. This decline highlights the complex interplay of exercise modality, intensity, and environmental factors in influencing aerobic fitness. The report explores potential physiological mechanisms underlying this observation, including the impact of heat stress on cardiovascular function and the limitations of low-intensity exercise in maintaining VO2 max. The role of wearable technology in fitness monitoring is also discussed, emphasizing the need for caution when interpreting data from these devices. Further considerations for personalized training approaches and the importance of continuous monitoring are emphasized.