Effects of intensity-matched exercise at different intensities on inflammatory responses in able-bodied and spinal cord injured individuals

Objective: To compare the effects of intensity-matched acute exercise at different intensities on proinflammatory and anti-inflammatory cytokines between able-bodied (AB) and spinal cord injured (SCI) individuals. Design: Non-Randomized Controlled Trial. Setting: Community settings in São Paulo–Brazil. Participants: Eight AB and nine SCI paraplegic. Interventions: Participants underwent three exercise sessions at different relative intensities: at ventilatory threshold 1 intensity (VT1), 15% below VT1, and 15% above VT1. Similar energy expenditures were established from exercises with different intensities for each volunteer. The AB group was tested on a conventional treadmill, whereas the SCI group was tested on a treadmill adapted for wheelchair use. Blood samples were collected at baseline, immediately after, and 30 min after the exercise sessions. Outcome measures: Interleukin 1 receptor antagonist, interleukin 1 beta, interleukin 2, interleukin 4, interleukin 6, interleukin 10 and tumoral necrosis factor alpha were measured. Results: When groups were compared, interleukin–2 was found higher, whereas interleukin–4 and interleukin–10 were found lower in the SCI group at all collection times in the three exercise intensities (all P < 0.05). Interleukin–1 receptor antagonist was found higher immediately after exercise at VT1, 15% above VT1 and 30 min after 15% below VT1 in the AB group (all P < 0.05). In the AB group, an increase in interleukin–6 immediately after the exercise at VT1 compared with baseline was found (P = 0.01). Conclusion: Individuals with SCI may have to perform physical exercise at a higher volume or energy expenditure than AB individuals to obtain similar anti-inflammatory benefits of acute exercise. Trial registration: Uniform Trial Number identifier: U1111-1232-8142.