(37) ISCHEMIC PRECONDITIONING DOES NOT AFFECT EARLY OR LATE PHASES OF RATE OF TORQUE DEVELOPMENT FOLLOWING SUBMAXIMAL FATIGUING RESISTANCE EXERCISE

Purpose: To examine the acute effects of ischemic preconditioning (IPC) on early and late phases of rate of torque development (RTD) prior to and immediately following submaximal fatiguing resistance exercise. Methods: Twelve (21.8 ±1.8 years, 162.2 ± 6.8 cm, 65.8 ± 12.2 kg) recreationally active females visited the laboratory on three separate occasions. The implementation of IPC was randomized and consisted of a low (20mmHg), moderate (80% of total arterial occlusion pressure [TAOP]), and high (220 mmHg) pressure with a pneumatic cuff placed most proximally on the dominant limb. Each participant underwent three cycles consisting of five minutes with the pressure applied followed by five minutes of rest. After completion of IPC, participants completed one-set to volitional failure of submaximal, unilateral isotonic leg extension muscle actions at 30% of their one-repetition maximum. To examine early (0 to 100 milliseconds) and late (0 to 200 milliseconds) phases of RTD, maximal voluntary isometric contractions (MVICs) were completed prior to and immediately following the one-set to volitional failure. Separate 3 (Condition [low, moderate, and high]) x 2 (Time [pretest, posttest]) repeated measure ANOVAs were performed. Results: There were no significant (p=0.463-0.673) interactions or main effects (p=0.247-0.476) of Condition for early or late RTD. There was, however, a significant main effect (p=0.015-0.045) of Time for early and late RTD. Specifically, collapsed across Condition, there were decreases from pretest to posttest for early (658.8 ± 230.3 Nm/sec to 544.9 ± 187.5 Nm/sec) (p=0.045) and late (547.6 ± 160.0 Nm/sec to 454.3 ± 141.2 Nm/sec) (p=0.015) RTD. Conclusions: The use of IPC did not affect early or late phases of RTD. Further, the implementation of various pressures did not impact RTD, suggesting no pressure-specific responses. Thus, the use of IPC does not provide an ergogenic effect on RTD prior to or after performing acute submaximal fatiguing resistance exercise. Practical Applications: Applying IPC prior to submaximal fatiguing resistance exercise does not affect early or late phases of RTD. Thus, coaches and/or practitioners should consider leveraging alternative approaches (e.g., post-activation potentiation) if preserving RTD or explosive power is a priority, particularly in sports which require repeated explosive movements. Acknowledgements: We would like to thank all participants for their time and effort.