Comparison of the Effects of Aerobic Conditioning Before and After Pulmonary Allergic Inflammation Ronaldo Aparecido da Silva, 1,2 Francine Maria Almeida, 2 Clarice Rosa Olivo, 2 Beatriz Mangueira Saraiva-Romanholo, 2,3 Adenir Perini, 2 Milton Arruda Martins, 2 and Celso Ricardo Fernandes Carvalho 1,2,4 Abstract—The aim of this study is to compare the effects of aerobic conditioning (AC) before (ACBS) and after (ACAS) allergic sensitization. BALB/c mice were divided into two main groups: ACBS and ACAS. Each groups was divided into subgroups: control (nonsensitized/nontrained), AC (nonsensi- tized/trained), ovalbumin (OVA) (sensitized/nontrained), AC + OVA (trained/sensitized), and OVA + AC (sensitized/trained). Sensitization was induced using OVA and AC performed in treadmill (moderate intensity). We examined IgE and IgG 1 levels, eosinophil counting, expression of Th1 (interleukin (IL)-2, IFN-α) and Th2 cytokines (IL-4, IL-5, IL-13), IL-10, vascular endothelial growth factor (VEGF), and airway remodeling. IgE and IgG 1 were decreased only when exercise was performed before sensitization (ACBS); however, there was a decrease of eosinophils, Th2 cytokines, VEGF, and airway remodeling and increase in IL-10 in either ACBS or ACAS groups. Our results demonstrate that aerobic condition- ing reduces Th2 response before and after sensitization by increasing IL-10 while the production of anaphylactic antibodies is reduced only when exercise is performed before sensitization. KEY WORDS: exercise; cytokine; allergy; immune system; remodeling. INTRODUCTION Studies have shown that improvements in physical fitness reduce low-grade systemic inflammation [1–3], sug- gesting that aerobic conditioning (AC) either at low or at moderate intensity can trigger anti-inflammatory effects in nonallergic diseases [4, 5]. Allergic diseases are distinct from low-grade inflammation, and the anti-inflammatory effect of AC on diseases such as asthma remains less understood. Allergic diseases are characterized by a pre- dominant Th2 response [6, 7], and the increase in its prev- alence has been associated with a western lifestyle (e.g., sedentary lifestyles and indoor entertainment), suggesting an imbalance in the immune response (Th1/Th2 pathways), a supposition referred to as the “hygiene hypothesis” [8, 9]. This hypothesis is reinforced by evidence showing that more physically active subjects have fewer respiratory symptoms [10] and that regular exercise is important in reducing allergic inflammation [11]. The benefits induced by AC in patients with allergic disease such as asthma were initially described by Clark and Cochrane [39] suggesting an increase in the ventilatory threshold. Later on, Pastva et al.[40] and Vieira et al.[13] showed that AC could reduce the airway inflammation in a murine asthma model, demonstrating that improvements in physical fitness can also reduce Th2 inflammation in aller- gic diseases such as asthma. More recently, a study also demonstrated that improvements in AC can reduce exhaled nitric oxide and eosinophil counting and in the sputum of asthmatic patients [12]. Although these anti-inflammatory effects of AC on allergic diseases have been suggested, the mechanisms remain poorly understood. In previous studies, we showed that AC reduces the Th2 response by decreasing the expression of the interleu- kin (IL)-4, IL-5, and IL-13 without altering the expression 1 Department of Physical Therapy, University of Sao Paulo, São Paulo, Brazil 2 Laboratory of Experimental Therapeutics LIM-20, School of Medicine, University of Sao Paulo, Av. Dr. Arnaldo, 455, Room 1210, 01246-903 São Paulo, SP, Brazil 3 University City of São Paulo (UNICID), São Paulo, Brazil 4 To whom correspondence should be addressed at Laboratory of Exper- imental Therapeutics LIM-20, School of Medicine, University of Sao Paulo, Av. Dr. Arnaldo, 455, Room 1210, 01246-903 São Paulo, SP, Brazil. E-mail: cscarval@usp.br 0360-3997/14/0000-0001/0 # 2014 Springer Science+Business Media New York Inflammation ( # 2014) DOI: 10.1007/s10753-014-0090-0