Validity of the peak velocity to detect physical training improvements in athymic mice

Abstract

This study comprises two complementary experiments with athymic Balb/c (Nu/Nu) mice. In experiment 1, the aim was to verify the reproducibility of the peak velocity (VPeak) determined from the incremental test. The second experiment aimed to assess the VPeak sensitivity to prescribe and detect modulations of the physical training in athymic nude mice. Sixteen mice were submitted to two incremental treadmill tests separated by 48-h (Experiment 1). The test consisted of an initial warm-up of 5 minutes. Subsequently, animals initiated the tests at 8 m min−1 with increments of 2 m min−1 every 3 minutes. The VPeak was determined as the highest velocity attained during the protocol. In experiment 2, these animals were randomly allocated to an exercise group (EG) or a control group (CG). The training protocol consisted of 30-min of treadmill running at 70% of the VPeak five times a week for 4 weeks. High indexes of reproducibility were obtained for VPeak (Test = 19.7 ± 3.6 m min−1; Retest = 19.2 ± 3.4 m min−1; p = 0.171; effect size = 0.142; r = 0.90). Animals from the EG had a significant increase of VPeak (Before = 18.4 ± 2.7 m min−1; After = 24.2 ± 6.0 m min−1; p = 0.023). Conversely, a significant decrease was observed for the CG (Before = 21.1 ± 3.9 m min−1; After = 15.9 ± 2.7 m min−1; p = 0.038). The VPeak is a valid parameter for exercise prescription in studies involving athymic nude mice.

High-Intensity Interval Training (Treadmill) Effects in Myokines and Endoplasmic Reticulum Stress of Calf Muscles in Obese Mice

“…High-intensity interval training protocol. After one week of acclimation (10 cm/s for 10 min), all animals were submitted to a peak velocity test (V peak ) in a treadmill (model LE8710; Panlab/Harvard Apparatus, Barcelona, Spain) (Kraemer et al, 2022). Mice started to exercise at 10 cm/s (0 % grade), progressively increasing speed to 5 cm/s every 3 min until exhaustion (mice's inability to reach the end of the treadmill line five times).…”

Accumulated experience of preying on escaping bait enhances pursuit performance in mice

“…Previous studies reveal that enhanced preying e ciency may be due to increased physical ability, experience, or both (Peterson et al 2021;Seebacher et al 2010). Improved physical ability may provide the hunter with greater stamina or explosive power, enabling it to capture prey more swiftly (Kraemer 2022). On the other hand, many animals may optimize their predatory skills through experience or learning (Zhang and Hui 2014).…”