The Effects of High Intensity, Short Rest Resistance Exercise on Testosterone and Muscle Damage Markers in Men and Women

High intensity, short rest protocols have become increasingly popular within the fitness industry. Such protocols can elicit extensive muscle damage and oxidative stress; thus the purpose of this study was to examine markers of muscle tissue damage and inflammation along with testosterone responses to a high intensity (75% 1RM), short rest resistance exercise protocol and sex-specific effects. Nine resistance trained men (age: 23.6 ± 3.5 years, weight: 77.8 ± 8.8 kilograms, height: 172.4 ± 4.0 cm, body fat 9.3 ± 3.3 %) and nine resistance trained women (age: 22.9 ± 2.0 years, weight: 68.6 ± 10.4 kilograms, height: 168.6 ± 9.4 cm, body fat 13.6 ± 3.3 %) participated. The protocol consisted of a descending pyramid scheme starting at 10 for three major lifts. No significant sex interactions were seen with testosterone or IL-6. There were significant sex interactions observed in myoglobin (IP) and CK (IP, +60, +24). Men demonstrated significant increases in testosterone (IP, +15), myoglobin (IP, +15, +60, +24), IL-6 (IP), and CK (IP, +60, +24). Women demonstrated significant increases in myoglobin (IP, +15, +60), IL-6 (IP), and CK (+24). There were no significant increases observed in women for testosterone. Women demonstrated a greater absolute increase in myoglobin per kilogram of fat free mass than men (+15, +60) indicating a sufficient degree of muscle damage. Both men and women demonstrated significant muscle damage with a high intensity, short rest protocol with different hormonal and immune responses, most likely mediated through differing signaling cascades