On Fitness
On Fitness ->->->-> https://urluss.com/2tCH5x
Objective: A prospective randomized controlled trial was designed to assess the benefits and possible risks of aerobic exercise during pregnancy, using a fitness regimen based on the 2002 American College of Obstetricians and Gynecologists guidelines for exercise during pregnancy.
Results: Compared with women who remained sedentary, active women improved aerobic fitness (P < 0.05) and muscular strength (P < 0.01), delivered comparable size infants with significantly fewer cesarean deliveries (P < 0.01), and recovered faster postpartum (P < 0.05), at least related to the lower incidence of cesarean section. Active women developed no gestational hypertension (P = 0.16 compared with controls) and reported no injuries related to the exercise regimen. In the active group, there was one premature birth at 33 wk by a woman with a history of premature delivery of twins at 34 wk. There were no differences between groups in the incidence of gestational diabetes, musculoskeletal pains during pregnancy, flexibility on sit-and-reach test, mean length of pregnancy, neonatal Apgar scores, placenta weights, overall length of labor, weight gain during pregnancy, or weight retention postpartum.
Fifty-four multiple sclerosis (MS) patients were randomly assigned to exercise (EX) or nonexercise (NEX) groups. Before and after 15 weeks of aerobic training, aspects of fitness including maximal aerobic capacity (VO2max), isometric strength, body composition, and blood lipids were measured. Daily activities, mood, fatigue, and disease status were measured by the Profile of Mood States (POMS), Sickness Impact Profile (SIP), Fatigue Severity Scale (FSS), and neurological examination. Training consisted of 3 x 40-minute sessions per week of combined arm and leg ergometry. Expanded Disability Status Scale (EDSS) scores were unchanged, except for improved bowel and bladder function in the EX group. Compared with baseline, the EX group demonstrated significant increases in VO2max, upper and lower extremity strength, and significant decreases in skinfolds, triglyceride, and very-low-density lipoprotein (VLDL). For the EX group, POMS depression and anger scores were significantly reduced at weeks 5 and 10, and fatigue was reduced at week 10. The EX group improved significantly on all components of the physical dimension of the SIP and showed significant improvements for social interaction, emotional behavior, home management, total SIP score, and recreation and past times. No changes were observed for EX or NEX groups on the FSS. Exercise training resulted in improved fitness and had a positive impact on factors related to quality of life.
\"I've never said we should just ignore overweight and obesity,\" Blair tells WebMD. \"But I do think the health hazards of the so-called obesity epidemic are overstated. That diverts attention from a bigger public health problem: declining levels of activity and fitness.\"
\"After all, we don't have very effective methods for weight loss,\" he says. \"Let's focus on what people can do -- which is eat a healthy diet and improve fitness. If everybody took three 10-minute walks a day, ate better, and consumed no more than moderate amounts of alcohol, they would be healthier whether they lost weight or not.\"
In 2014, boutique fitness studios represented 42% of the market, a 100% increase over 2013, according to the International Health, Racquet & Sportsclub Association. The 2016 IHRSA Health Club Consumer Report found that millennials in particular prefer specialized classes like cross-training, pilates and yoga as opposed to Gen-Xers who are perfectly fine on the elliptical. Rather than pay a more affordable $20 a month at a no-frills gym like Planet Fitness, millennials are going to workout for the experience at niche studios specializing in barre, kickboxing or high-intensity interval training. And the intimate, social environment makes the 45-minutes to an hour long classes feel more like a club than a sweat zone, experts say.
Mutualistic exchange of metabolites can play an important role in microbial communities. Under natural environmental conditions, such exchange may be compromised by the dispersal of metabolites and by the presence of non-cooperating microorganisms. Spatial proximity between members during sessile growth on solid surfaces has been shown to promote stabilization of cross-feeding communities against these challenges. Nonetheless, many natural cross-feeding communities are not sessile but rather pelagic and exist in turbulent aquatic environments, where partner proximity is often achieved via direct cell-cell adhesion, and cooperation occurs between physically associated cells. Partner association in aquatic environments could be further enhanced by motility of individual planktonic microorganisms. In this work, we establish a model bipartite cross-feeding community between bacteria and yeast auxotrophs to investigate the impact of direct adhesion between prokaryotic and eukaryotic partners and of bacterial motility in a stirred mutualistic co-culture. We demonstrate that adhesion can provide fitness benefit to the bacterial partner, likely by enabling local metabolite exchange within co-aggregates, and that it counteracts invasion of the community by a non-cooperating cheater strain. In a turbulent environment and at low cell densities, fitness of the bacterial partner and its competitiveness against a non-cooperating strain are further increased by motility that likely facilitates partner encounters and adhesion. These results suggest that, despite their potential fitness costs, direct adhesion between partners and its enhancement by motility may play key roles as stabilization factors for metabolic communities in turbulent aquatic environments.
To quantitatively characterize the importance of these factors in a well-defined model community, we established a synthetic interkingdom cross-feeding consortium between the bacterium Escherichia coli and the budding yeast Saccharomyces cerevisiae, in which the physical association between the two partners is mediated by the bacterial type I fimbriae [40] and both adhesion and bacterial motility could be easily manipulated. We demonstrate that cell adhesion, and possibly the resulting cell clumping, provide moderate but significant competitive advantage to fimbriated bacteria in a well-mixed co-culture with yeast, despite modest reduction of the overall community growth. Physical interaction was further important to exclude non-cooperating bacterial cheaters, thereby delaying the collapse of the community upon cheater invasion. Swimming provides an additional fitness advantage to the adhesive bacterial partner and further increases its competitiveness against the cheater. These findings demonstrate that investments in adhesion and motility can be beneficial for mutualistic microbial communities existing in turbulent aquatic environments.
In aquatic environments, the ability of cells to actively move could increase the encounter rate between partners, but it might also enhance cell detachment. To test the impact of motility on the relative fitness of bacteria in our community, we performed competition assays between motile and non-motile E. coli partners co-cultured with yeast (Fig. 5A). Two different non-motile strains of E. coli were used, either deleted for flagellin gene fliC and thus lacking flagellar filaments, or deleted for the flagellar motor gene motA and displaying non-functional, yet structurally intact, flagella. Moreover, we further tested a motile but non-chemotactic E. coli strain (ΔcheY) that is no longer capable of following chemical gradients in the environment. Since the motility of the parental strain E. coli BW25113 used in the previous experiments is generally poor, and large spontaneous variability of swimming abilities was reported for its derivatives [50], here we used another common K12-derived strain MG1655, where ΔtyrA and the aforementioned motility and chemotaxis mutations were introduced. Furthermore, since motility gene expression in E. coli is repressed by glucose [51], fructose was used instead as the carbon source. All knockout strains showed the expected motility phenotypes under these experimental growth conditions (Fig. S19). Moreover, no effects of fimbriation on swimming (Fig. S20) or of motility on the on/off state of the fim promoter (Fig. S21) were observed, confirming that motility and fimbriation do not exhibit cross-regulation under our experimental conditions.
Motility was observed to provide a significant competitive fitness benefit to E. coli at low initial cell densities and under conditions of mixing in an orbital shaker, with over 60% of the final E. coli partner population being wildtype for motility at the initial OD of 0.001 (Fig. 5B), which is comparable to typical microbial cell densities in aquatic environments [52]. This was true for competition with either ΔmotA or ΔfliC strains, suggesting that this effect is purely determined by motility, and not by possible flagella-mediated adhesion [53]. In contrast, chemotaxis does not seem to provide benefit under these conditions, since the fraction of a non-chemotactic but motile ΔcheY stain was not statistically different from 50% even at low initial cell density. The benefit of E. coli motility in the cross-feeding co-culture decreased and eventually inverted at lower shaking rates (Fig. 5B and Fig. S22), and both non-motile strains clearly outcompeted the motile one when the culture was grown in the absence of shaking, possibly as a consequence of co-sedimentation between non-motile E. coli and S. cerevisiae cells. The slight but significant increase in fitness of ΔcheY compared to the chemotactic strain in the absence of shaking could also be due to its known [54] increased residence time at the surface (Fig. S19B, G, H), and therefore more frequent encounters with sedimented yeast cells. 781b155fdc