Cold-water immersion blunts and delays increases in circulating testosterone and cytokines post-resistance exercise

Introduction Cold-water immersion (CWI) is often used to promote recovery by reducing exercise-induced muscle damage, soreness, and inflammation. However, recent reports have cautioned that CWI may attenuate the adaptive response to resistance training. Purpose To determine the effect of post resistance-exercise CWI on circulating free testosterone (T) and cytokine (IL-6 and TNF-α) response. Methods Using a randomized and counterbalanced repeated-measures design, 11 resistance-trained men completed two workouts (6 sets of 10 repetitions of back squats at 80% of maximum load) a week apart after which they took part in either 15 min of CWI (15 °C) or passive recovery. T, IL-6, and TNFα were measured in blood samples taken before (PRE) and 5 (5POST), 15 (15POST), 30 (30POST), and 60 (60POST) min post-exercise and compared between treatments and over time. Results For T, a significant interaction effect of condition over time ( p = 0.030) as well as greater relative concentrations of T in CON (Δ9.2%) than CWI (Δ-0.5%, p = 0.049) at 30POST were observed. In addition, at 60POST, T dropped below PRE values in CWI (Δ-10.4%, p = 0.028) but not in CON (Δ-1.6%, p = 0.850). A suppressed cytokine response was observed after CWI in IL-6 at 30POST (CWI: Δ4.9%, CON: Δ47.5%, p = 0.041) and TNFα at 15POST (CWI: Δ5.3%, CON: Δ17.0%, p = 0.022). Conclusions CWI blunted the T and cytokine response after a bout of resistance exercise. These results indicate that CWI results in an altered anabolic response and may help to explain the previous observation of attenuated hypertrophy when CWI is used after resistance exercise.