Aqua training promotes changes of skeletal muscle mass in show jumping horses.

Overview

• This study investigated how training show jumping horses on an aquatic treadmill affects their skeletal muscle mass and performance.
• The research showed that adding water treadmill sessions to regular exercise increased muscle mass, muscle activity, and specific jumping performance metrics without changing fat mass.

Introduction and Objective

• The correct use of aquatic treadmill training for competitive horses requires understanding how water-based exercise affects muscle development.
• The study aimed to test whether incorporating water treadmill training into a horse’s regular routine changes muscle mass and improves muscular function relevant to show jumping.

Methods

• Subjects: Six show jumping horses in competition-ready fitness condition.
• Training Intervention: Each horse underwent 10 weeks of training, including 20-minute sessions twice weekly on an aquatic treadmill with water level at the carpus (horse’s wrist area).
• Regular Exercise: Horses continued their usual physical training alongside the aquatic treadmill work.
• Assessments conducted before and after the training period included:
  • Body composition measurements focusing on body weight, fat-free mass, and fat mass.
  • Infrared thermography (IRT) to measure surface temperature of key propulsive muscles: brachiocephalic, semitendinosus, semimembranosus.
  • Blood enzyme tests (AST and CK) to monitor muscle activity and recovery after field jumping tests.
  • Kinematic parameters of jumping such as strike power, take-off angle, and aerial phase duration for vertical and oxer jumps.
• Statistical analysis: Paired t-tests were used to evaluate changes before and after the intervention with significance level p<0.05.

Results

• Body composition:
  • Body weight increased significantly from approximately 550.5 kg to 587.0 kg.
  • Fat-free mass (muscle and lean tissue) increased significantly from about 485.1 kg to 520.1 kg.
  • Fat mass stayed stable around 65-67 kg, with no significant change in rump fat thickness, indicating muscle gain rather than fat gain.
• Muscle activity and biochemistry:
  • Infrared thermography showed increased temperature in the brachiocephalic, semitendinosus, and semimembranosus muscles after training, suggesting greater muscle recruitment or blood flow.
  • Both aspartate aminotransferase (AST) and creatine kinase (CK) levels rose post-training, which are markers linked to muscle metabolism and response to exercise.
• Jumping performance:
  • Vertical jumps showed improvements in strike power (force of impact with ground), from 2.53 G to 3.18 G.
  • Take-off angle increased significantly for vertical jumps (20° to 24.5°) and oxer jumps (21.7° to 26.1°), indicating better jump technique or strength.
  • Duration of the aerial phase (time in the air) in vertical jumps lengthened from 665.3 ms to 765.3 ms, reflecting enhanced jumping ability.

Conclusions

• Adding water treadmill sessions to regular training promotes muscular recruitment in key propulsive muscles of show jumping horses.
• The significant gain in muscle mass is primarily in fat-free tissue, implying improved muscle development rather than fat accumulation.
• Enhanced muscle strength contributes to better take-off power, jump angles, and aerial phase duration, all indicators of improved jumping performance.
• The training likely improves core strength to elevate the forehand (front of the horse) and strengthens hind limb muscles responsible for propulsion.
• Overall, aquatic treadmill training appears to be an effective supplement to traditional conditioning for competitive show jumping horses.