Periodized versus non-periodized swimming training with equal total training load: Physiological, molecular and performance adaptations in Wistar rats

Abstract

This study investigated the effect of non-periodized training performed at 80, 100 and 120% of the anaerobic threshold intensity (AnT) and a linear periodized training model adapted for swimming rats on the gene expression of monocarboxylate transporters 1 and 4 (MCT1 and 4, in soleus and gastrocnemius muscles), protein contents, blood biomarkers, tissue glycogen, body mass, and aerobic and anaerobic capacities. Sixty Wistar rats were randomly divided into 6 groups (n = 10 per group): a baseline (BL; euthanized before training period), a control group (GC; not exercised during the training period), three groups exercised at intensities equivalent to 80, 100 and 120% of the AnT (G80, G100 and G120, respectively) at the equal workload and a linear periodized training group (GPE). Each training program lasted 12 weeks subdivided into three periods: basic mesocycle (6 weeks), specific mesocycle (5 weeks) and taper (1 week). Although G80, G100 and G120 groups were submitted to monotony workload (i.e. non-modulation at intensity or volume throughout the training program), rodents were evaluated during the same experimental timepoints as GPE to be able comparisons. Our main results showed that all training programs were capable to minimize the aerobic capacity decrease promoted by age, which were compared to control group. Rats trained in periodization model had reduced levels of lipid blood biomarkers and increased hepatic glycogen stores compared to all other trained groups. At the molecular level, only expressions of MCT1 in the muscle were modified by different training regimens, with MCT1 mRNA increasing in rats trained at lower intensities (G80), and MCT1 protein content showed higher values in non-periodized groups compared to pre-training and GPE. Here, training at different intensities but at same total workload promoted similar adaptations in rats. Nevertheless, our results suggested that periodized training seems to be optimize the physiological responses of rats.

Whey Protein, Soy Protein Isolate Hydrolysate, and Amino Acid Mixture in Adaptation to Physical Stress of Rats

“…Despite this, we conducted a safety study on rats and showed no toxic effect of consuming hydrolysate three times a week before phisical load for 32 days. The body weight gain of all three groups of animals continued throughout the experiment, which coincides with the data in the group of Wistar rats of the same age without any manipulation in previously published works [15,20]. The feed intake during the whole experiment did not differ between all three groups.…”

“…Sexually mature male rats of the outbred Wistar stock were used. At the time of randomization, the rats were 12 weeks old, 280.8 g., SD=21.4 g. This animal model is recognized as suitable for studying nutrition problems and adaptation to physical stress (swimming) [15][16][17]. The initial sample size was 10 individuals in each group.…”

Chinese Soft-Shelled Turtle Oil in Combination With Swimming Training Improves Spatial Memory and Sports Performance of Aging Rats

“…The glycogen levels in soleus muscle samples were measured using a glycogen colorimetric assay kit (BioVision) according to the manufacturer's instructions. Soleus was selected as the target muscle for this study as studies have shown that soleus muscle is one the key muscle types that can be improved with swimming training in rat model (Forte et al, 2020;Moustafa and Arisha, 2020).…”