Abstract: Objective This study analyzed the athletic performance and physiological indicators of two top seated cross-country skiers during simulated competitions, and explored the characteristics of exercise intensity and pacing strategies under different terrains. It aims to provide a scientific basis for athletes' physical fitness allocation and the optimization of speed rhythm.Methods Differential GPS (positioning accuracy less than 0.1 m, sampling frequency greater than 10 Hz) and Momentum Technology MT-Sports T2 were used to test two athletes with Locomotor winter 10 (LW 10), the first and second runners-up of Beijing Winter Paralympic Middle Distance Sitting Cross-Country Skiing, Zheng* and Mao**. The athletes' real-time glide speed and heart rate during five consecutive 15 km country skiing time trials were collected and analyzed for time spent, speed and heart rate changes in each course. Results (1) the coefficient of variation of total time spent and average heart rate in uphill and flat terrain sections were significantly correlated with total performance; (2) the average speed and average heart rate as a percentage of maximum heart rate of athletes gliding in the three terrains were significantly correlated with total performance; (3) the correlation between average time spent in uphill and flat terrain and total performance was stronger than that between average time spent in downhill terrain and total performance;(4) Both athletes used a cumulative acceleration speed rhythm. Conclusions (1) Uphill and flat terrain times are critical to race performance, with uphill accounting for over half of the total time and showing the strongest correlation with results, followed by flat terrain, while downhill impact varies individually. Training should prioritize endurance and speed in uphill and flat sections and optimize skiing techniques for efficiency. (2) Athletes adopt a progressive pacing strategy, gradually increasing speed in the first half, maintaining stable output mid-race, and finishing with a high-speed lap. The average speeds in laps 2 and 3 and heart rate changes in the final lap are the strongest predictors of performance, highlighting the need to optimize energy distribution and pacing in key laps. (3) Heart rates are mainly distributed between 70-90% HRmax, and balancing high-intensity effort on uphills with recovery on downhills helps optimize energy expenditure.