Aquatic Treadmill Exercise Combined With Resistance Exercise Yields Different Cytokine Responses Compared To Land Treadmill

Abstract

We have previously shown that aquatic treadmill (ATM) running may alter acute inflammatory responses when performed after resistance exercise (RT). PURPOSE: To investigate the effects of RT alone and combined with either land treadmill (RT-LTM) or ATM exercise (RT-ATM) on TNFα, IL-6, IL-8, IL-10, INFg, and GMCSF. METHODS: Forty-seven untrained men (n=23, 37±11yrs, 182.7±6.7cm, 98.9±16.1kg) and women (n=24, 38±12yrs, 165.6±4.8cm, 82.1±19.1kg) were randomized into three groups: RT-LTM, RT-ATM, and RT, then assigned progressive RT (2/wk, 3 x 8-12 repetitions, 60◊85% 1RM) for 12wk. The RT-ATM and RT-LTM groups progressively added ATM or LTM immediately following RT sessions and in isolation on a 3rd day to total up to 500 kcal/bout. Muscular strength, body composition, and VO2max were measured before and after training. Fasting blood samples were obtained before and 24h after acute exercise before and after training for analysis serum cytokines. A 3(group) x 2(time) mixed model ANCOVAs (covaried on baseline values) were used to detect acute changes in serum cytokines and chronic changes in VO2max, strength, and body composition (α=0.05). RESULTS: In the untrained state, acute RT-LTM exercise was found to significantly increase IL-6 (+71.04% ±31.23). Acute RT-ATM exercise yielded greater increases in IL-10 in the untrained state (+44.11% ±18.41) than RT-LTM (-1.15% ±13.39). Additionally, acute RT-ATM exercise was observed to increase INFg in the untrained state (+111.42% ±48.55). In the trained state, RT-ATM exercise elicited a greater increase in IL-10 (+67.77% ±21.72) than RT-LTM (-2.81% ±10.77) and RT (-4.29% ±9.45). All groups were found to have significant increases in total strength with RT-ATM (+608.53lbs ±75.0) eliciting a greater increase than RT-LTM (+364.38lbs ±39.0) and RT (+432.78lbs ±46.0). All groups were found to have significant increases in VO2max with RT-LTM (+2.79ml/kg/min ±0.6), RT-ATM (+3.36 ml/kg/min ±0.6), and RT (+5.85 ml/kg/min ±0.7) being statistically different from the other. Both RT-ATM (-1.71 ±0.4) and RT-LTM (-2.79 ±0.4) exercise were found to decrease body fat. CONCLUSION: Cytokine responses related to pro-inflammatory, anti-inflammatory, and metabolic signaling are mode dependent and may affect training adaptations.