Post-exercise cold water immersion does not alter high intensity interval training-induced exercise performance and Hsp72 responses, but enhances mitochondrial markers

Abstract

This study aims to evaluate the effect of regular post-exercise cold water immersion (CWI) on intramuscular markers of cellular stress response and signaling molecules related to mitochondria biogenesis and exercise performance after 4 weeks of high intensity interval training (HIIT). Seventeen healthy subjects were allocated into two groups: control (CON, n = 9) or CWI (n = 8). Each HIIT session consisted of 8-12 cycling exercise stimuli (90-110 % of peak power) for 60 s followed by 75 s of active recovery three times per week, for 4 weeks (12 HIIT sessions). After each HIIT session, the CWI had their lower limbs immersed in cold water (10 °C) for 15 min and the CON recovered at room temperature. Exercise performance was evaluated before and after HIIT by a 15-km cycling time trial. Vastus lateralis biopsies were obtained pre and 72 h post training. Samples were analyzed for heat shock protein 72 kDa (Hsp72), adenosine monophosphate-activated protein kinase (AMPK), and phosphorylated p38 mitogen-activated protein kinase (p-p38 MAPK) assessed by western blot. In addition, the mRNA expression of heat shock factor-1 (HSF-1), peroxisome proliferator-activated receptor gamma coactivator-1α (PGC-1α), nuclear respiratory factor 1 and 2 (NRF1 and 2), mitochondrial transcription factor A (Tfam), calcium calmodulin-dependent protein kinase 2 (CaMK2) and enzymes citrate synthase (CS), carnitine palmitoyltransferase I (CPT1), and pyruvate dehydrogenase kinase (PDK4) were assessed by real-time PCR. Time to complete the 15-km cycling time trial was reduced with training (p < 0.001), but was not different between groups (p = 0.33). The Hsp72 (p = 0.01), p38 MAPK, and AMPK (p = 0.04) contents increased with training, but were not different between groups (p > 0.05). No differences were observed with training or condition for mRNA expression of PGC-1α (p = 0.31), CPT1 (p = 0.14), CS (p = 0.44), and NRF-2 (p = 0.82). However, HFS-1 (p = 0.007), PDK4 (p = 0.03), and Tfam (p = 0.03) mRNA were higher in CWI. NRF-1 decrease in both groups after training (p = 0.006). CaMK2 decreased with HIIT (p = 0.003) but it was not affected by CWI (p = 0.99). Cold water immersion does not alter HIIT-induced Hsp72, AMPK, p38 MAPK, and exercise performance but was able to increase some markers of cellular stress response and signaling molecules related to mitochondria biogenesis.

Keywords: Cold water immersion; Heat shock protein; High intensity interval training; Mitochondria biogenesis; Post-exercise recovery.

Fig. 1

Timeline of all experimental procedures before, during, and after the 4 weeks of weeks of high intensity interval training for both experimental groups

Fig. 2

The 15-km time trial performance-related data before (pre) and after (post) 4 weeks of high intensity interval training for control and cold water immersion groups. Time to complete the time trial (a), time to complete each kilometer during the time trial (b), mean power output (expressed as % of pre-training maximal power output) during time trials (c), mean power output to complete each kilometer during time trial (d), heart rate (expressed as % of maximal heart rate) during time trials (e), and rating of perceived exertion scores during time trials (f). Asterisk indicates training effect (P < 0.05). Data are expressed as mean ± standard error. Two-way ANOVA, CON = control, CWI = post-exercise cold water immersion, PRE = before training, and POST = after training

Fig. 3

Representative blot and mean expression for Hsp72 (a), AMPK (b), and p-p-38 MAPK proteins (c) before (pre) and after (post) 4 weeks of high intensity interval training for control and cold water immersion groups. Data are expressed as mean ± standard error. Asterisk indicates P ≤ 0.05 for training effects. CON = control, CWI = post-exercise cold water immersion, PRE = before training, and POST = after training. The blottings are representative of each independent experiment

Fig. 4

Mean fold change for PGC-1α (a), NRF-1 (b), NRF-2 (c), Tfam (d), CaMK2 (e), CPT1 (f), CS (g), HFS-1 (h), and PDK4 (i) mRNA before (pre) and after (post) 4 weeks of high intensity interval training for control and cold water immersion groups. Data are expressed as mean ± standard error. Asterisk indicates P ≤ 0.05 for differences training effects. Number sign indicates P ≤ 0.05 for differences in between conditions. CON = control, CWI = post-exercise cold water immersion, PRE = before training, and POST = after training