Exercise training at MLSS decreases weight gain and increases aerobic capacity in obese Zucker rats.

This study aimed to identify the aerobic capacity enhancement and subsequent body weight (BW) status of obese Zucker rats (OZRs) after 4 weeks of treadmill running exercise at the maximal lactate steady state (MLSS). In addition to obese Zucker rats (OZRs), lean Wistar Kyoto rats (WKYs) were used, and both species were divided into control and exercise groups as follows: obese exercise (OZR-EX, n=5), obese control (OZR-CON, n=5), lean exercise (WKY-EX, n=5) and lean control (WKY-CON, n=5). The OZR and WKY exercise groups trained 5 days per week at 12.5 m.min-1 and 20 m.min-1, respectively. After 4 weeks of training, MLSS was ascertained to evaluate the animals' aerobic capacity using 3 different velocities (12.5, 15 and 17.5 m.min-1 for OZRs and 25, 30 and 35 m.min-1 for WKYs). The MLSS of OZR-EX was identified at the velocity of 15 m.min-1, representing a 20% increase in aerobic capacity after the exercise program. The MLSS of WKY-EX was identified at 30 m.min-1 with a 50% increase of in aerobic capacity. Obese animals that exercised showed reduced weight gain compared to the non-exercise obese control group (p <0.05). Our results thus show that exercise training at MLSS intensity increased the aerobic capacity in both obese and non-obese animals and also reduced BW gain.

Effects of physical exercise on Akkermansia muciniphila: a systematic review of human and animal studies.

This systematic review aimed to compile various research designs, including experimental, longitudinal, cross-sectional, and case studies in humans and experimental studies in rodents, to examine changes in Akkermansia muciniphila abundance in response to exercise. This comprehensive approach can improve our understanding of A. muciniphila response to physical exercise and highlight gaps in the literature, providing valuable insights for future microbiome research. Four databases (Web of Science, PubMed, Scopus, and Sports Discuss) were searched in the literature. Quality assessment was conducted independently and in duplicate using two risk-of-bias tools (Downs and Black for human studies and SYRCLE's risk of bias for animal studies). 3,901 studies were identified, with thirteen human studies and nine animal studies included after screening. Of the thirteen human studies analysed, five (38.5%) were cross-sectional, seven (53.8%) were longitudinal/experimental, and one (7.7%) was a case study. These studies included 522 participants, among whom 157 were athletes, such as rugby players, marathon runners, triathletes, and skiers. Six studies reported an increase in A. muciniphila, five showed a decrease, and two found no significant differences. Regarding interventions, two studies used a combination of moderate-intensity strength and aerobic training, while seven used low to moderate-intensity aerobic exercises. In the nine rodent studies, eight (88.9%) were conducted on mice and one (11.1%) on rats, with all being experimental. These studies involved 310 animals. Eight studies reported a substantial increase in A. muciniphila, while one found no differences. Among these, eight employed moderate-intensity aerobic exercises as the intervention, and one utilised low-to-moderate-intensity strength training. The studies summarised in this review indicate that the impact of various physical exercise protocols on A. muciniphila abundance in humans remains controversial. However, rodent studies provide strong evidence that aerobic exercise increases A. muciniphila abundance in faecal pellets of both healthy and diseased models.

Determination of the maximal lactate steady state in obese Zucker rats.

This study aims to identify the maximum lactate steady state (MLSS) in obese rats in order to provide a more effective tool in the exercise training prescription for this important animal model. To make such determination, obese (Zucker, n=5) (390.0±18.8 g) and lean (Wistar, n=5) (227.3±26.2 g) rats were studied. After adaptation of animals to treadmill, the MLSS was determined by using 3 different velocities (10 m.min⁻¹, 12.5 m.min⁻¹ and 15 m.min⁻¹ for Zucker and 15 m.min⁻¹, 20 m.min⁻¹ and 25 m.min⁻¹ for Wistar). The MLSS was defined as the highest blood lactate concentration that increased up to 1 mmol.L⁻¹ during constant exercise. In obese rats, the MLSS was found in a velocity considerably lower than in lean controls (12.5 m.min⁻¹ and 20 m.min⁻¹), respectively (p<0.05). Therefore, the identification of MLSS in obese Zucker rats is an important tool for exercise prescription and evaluation in obese rat models.