Does Post Exercise Cold Water Immersion Alter Intramuscular Hsp72 After 4 Weeks Of High Intensity Interval Training?

Abstract

Cold water immersion (CWI) is a recovery strategy commonly employed by athletes. The purpose of its use is based on possible reductions in muscle inflammation, oedema, and fatigue, thereby facilitating recovery. Furthermore, it is not clear if CWI can interfere with intramuscular signaling adaptation and with exercise performance. PURPOSE: the purpose of the present study was to evaluate the effect of CWI in intramuscular heat shock protein 72 kda (Hsp72) and exercise performance after 4 weeks of high intensity interval training (HIIT). METHODS: 17 healthy subjects (age: 23 ± 3 years old, body weight: 68.7 ± 9.2 kg, height 171 ± 7 cm; body fat: 23.5 ± 5.2%) were allocated into 2 groups: control (CON, n=9) and cold water immersion (CWI, n=8). Vastus lateralis biopsies were obtained pre and post training. To evaluate intramuscular content of Hsp72, we performed western blot. Exercise performance was evaluated before and after 4 weeks of HIIT through an individualized ramp test and 15 km cycling time trial. Each HIIT session consisted of 8-12 cycling exercise stimuli (90-110% of the peak power) for 60 seconds followed by active recovery intervals of 75 seconds at 30W 3 times per week. After each HIIT session, the CWI group had their lower limbs immersed in cold water (10°C) for 15 minutes and the CON group recovered at room temperature. RESULTS: The Hsp72 muscle content increased with training, but was not different between recovery methods (CON 100 ± 28% to 124 ± 37% and CWI 100 ± 31% to 131 ± 23%, p=0.29). Time to complete the time trial reduced with training (p<0.001), but was not different between recovery methods (p=0.33, CON 42.9 ± 1.9 to 38.7 ± 2.9 min and CWI 42.4 ± 2.5 to 37.7 ± 3.0 min, pre versus post, respectively). Maximum oxygen consumption (VO2max) increased with training in both groups (p=0.001), but was not different between recovery methods (p=0.43, CON 48.7 ± 5.6 to 51.2 ± 4.8 ml.kg-1.mim-1 and CWI 45.7 ± 5.6 to 50.4 ± 4.8 ml.kg-1.mim-1, pre versus post, respectively). The HIIT protocol was effective in improving performance, but the recovery intervention did not affect intramuscular Hsp72. CONCLUSION: We conclude that cold water immersion does not alter training induce intramuscular Hsp72 adaptations and exercise performance induced by HIIT. Supported by FAPEMIG (APQ-01382-12), CAPES and CNPq (407252/2013-4)