Swimming Rats

The objective of this study was to verify the swimming training periodization responses on aerobic and anaerobic performance, glycogen concentration in muscle (M) and liver (L), and creatine kinase (CK) in rats. Seventy male Wistar rats were randomly separated in two groups: Control Group (CG n = 30) and Training Periodization Group (TPG n = 30). All experiments were preceded by 2 weeks of individual adaptation to the water. The TPG was carried out during a period of 12 weeks (w) with frequency of 6 days/w. The training period was subdivided in three specialized series blocks: Preparation (6 w), Specific (4.5 w) and Taper (1.5 w). The Lactate Minimun Test (LACm) was adapted to determine the aerobic capacity. Anaerobic performance was evaluated by maximal exhaustion time (Tlim) verified during hyperlactatemia induction phase in the LACm protocol. Training stimulus was based on intensities corresponding to the LACm: Endurance (END) 1 = 80%; END2= 100%; END3= 120% and Anaerobic (ANA) 240% of the LACm. Two-way Anova and Newman-Keuls post-hoc test (P<0.05)were also used. Aerobic performance was not different from initial training (Preparation: 4.57 ± 0.24% of body weigh (bw); Specific: 4.59 ± 0.44 %bw), but at the end of taper, the LACm was higher (Taper: 5.01 ± 0.71% bw). The anaerobic parameter (Tlim) was significantly higher at the end of taper (73 ± 14s) when compared to the Preparation (50 ± 13s) and Specific blocks (65 ± 18s). The CG reduced the LACm and anaerobic performance along the experimental period. The glycogen M increased after taper but CK did not alter during training. Training periodization in rats acted as an important tool to evaluate specific effects of training. This is supported by sensitive responses of the rats along the blocks, based on improvement of aerobic and anaerobic performance as well as glycogen concentration obtained after the taper block.