Correlation Between Surface Temperature Of Muscle Group And Swimming Level Based On Infrared Thermal Imager

Correlation between surface temperature of major muscle group and swimming training level based on infrared thermal imager PURPOSE: The change of muscle surface temperature reflects the ability of muscle recruitment of swimmers, which is closely related to swimming level. The study aimed to study the relationship between the surface temperature of major muscle groups and different swimming level by using infrared thermal imager. METHODS: 21 male swimmers were recruited for the experiment and divided into three groups: beginner group (FINA point under 440), amateur group (FINA point: 440 to 621) and elite group (FINA point: 621 to 723). Each experiment session included 20 minutes warm-up and 50 m freestyle simulated competition. Surface temperature of quadriceps, biceps femoris, pectoralis major, rectus abdominis, latissimus dorsi, deltoid, triceps, biceps brachii were measured. Two tests were taken at rest before warm-up and after the simulation test. A medical thermal imaging camera with a temperature resolution of ≤0.05 °C/30 °C and an image resolution of 380 × 488 was used. RESULTS: No significant difference in the body surface temperature of the main muscle groups of all the subjects (p > 0.05) in the first test. In intra-group comparative analysis, no significant difference in elite group (P > 0.5), beginner group and amateur group both showed significant differences (p < 0.5). In elite group, temperature of biceps femoris and increased 0.4 °C and 0.5 °C after the second test while others declined. Among all muscle groups, temperature of rectus abdominis decreased the most with 2.7 °C, while deltoid increased 0.8 °C in amateur group. Temperature of all muscle groups in beginner group decreased with quadriceps decreased 2.6 °C remarkably. In inter-group comparative analysis, elite group showed smallest magnitude of the declined 0.72 °C of average temperature of all muscle groups, while beginner group and amateur group declined 1.56 °C and 1.3 °C separately. CONCLUSION: Positive relationship between surface temperature of major muscle group and swimming training level. The higher the swimming level the more accurate swimmers could mobilize corresponding muscle groups, hence maintained or increased the heat production and improve swimming performance.