High-intensity interval training induces a modest systemic inflammatory response in active, young men

Abstract

1) the extent to which an acute session of high-intensity interval training (HIIT) increases systemic inflammatory cytokines and chemokines, and 2) whether 2 weeks of HIIT training alters the inflammatory response. Eight recreationally active males (aged 22±2 years) performed 2 weeks of HIIT on a cycle ergometer (six HIIT sessions at 8-12 intervals; 60-second intervals, 75-second active rest) at a power output equivalent to 100% of their predetermined peak oxygen uptake (VO2max). Serum samples were collected during the first and sixth HIIT sessions at rest and immediately, 15, 30, and 45 minutes post-exercise. An acute session of HIIT induced significant increases in interleukin (IL)-6, IL-8, IL-10, tumor necrosis factor-α, and monocyte chemotactic protein-1 compared with rest. The concentrations of interferon-γ, granulocyte macrophage-colony-stimulating factor, and IL-1β were unaltered with an acute session of HIIT Two weeks of training did not alter the inflammatory response to an acute bout of HIIT exercise. Maximal power achieved during a VO2max test significantly increased 4.6%, despite no improvements in VO2max after 2 weeks of HIIT. These data suggest that HIIT exercise induces a small inflammatory response in young, recreationally active men; however, 2 weeks of HIIT does not alter this response.

Keywords: cycle ergometer; exercise training; inflammatory cytokines.

Figure 1

Protocol schematic. Subjects completed eight total visits over a 3-week period, including a pre-training testing session and HIIT familiarization session, six HIIT sessions, and a post-training testing session. Blood was collected during HIIT session 1 and HIIT session 6 for the analysis of inflammatory cytokines and chemokines. Abbreviation: HIIT, high-intensity interval training.

Figure 2

Serum inflammatory cytokines in response to an acute bout of HIIT. IL-6 (A), IL-8 (B), MCP-1 (C), TNF-α (D), and IL-10 (E) concentrations were measured before and immediately (Imm), 15, 30, and 45 minutes after completion of an acute bout of HIIT exercise (at a workload equivalent to 100% of VO₂max) on a cycle ergometer during the first and sixth HIIT exercise sessions. Notes: Open bars, first HIIT session; filled bars, sixth HIIT session. Data are reported as mean ± SD; n=7.*indicates significantly different from at rest. Abbreviations: HIIT, high-intensity interval training; IL, interleukin; MCP, monocyte chemotactic protein; SD, standard deviation; TNF, tumor necrosis factor; VO₂max, peak oxygen uptake.