Cable yarding operations on steep terrain have always been a challenge with respect to safety as they are mostly undertaken by manual laborers, particularly in South Korea. Steep slopes are associated with a high workload for choker setters. Therefore, the main goals of this study were to determine the heart rate and oxygen consumption of choker setters and evaluate their workload during clear-cut operations on a Larix kaempferi stand using a Polar M400, H7 heart rate sensor. Three choker setters were continuously evaluated during one working day. Overall, the mean working heart rate (HRw) during choking operations ranged from 87 to 104 bpm at a maximum oxygen consumption rate of 0.9 to 1.4 L/min. The choker setters recorded most of the effective work time on the “wait” (68.5%) and “walk-in” (7.8%) work elements. In addition, the physiological workload differed among the various elements of the cable yarding operation, with a higher HRw associated with a higher workload. Our findings may provide useful information for managing the health and safety of forestry crews during cable extraction activities.