Background Due to the SARS-CoV2 pandemic, medical face masks are widely recommended for a large number of individuals and long durations. The effect of wearing a surgical and a FFP2/N95 face mask on cardiopulmonary exercise capacity has not been systematically reported. Methods This prospective cross-over study quantitated the effects of wearing no mask (nm), a surgical mask (sm) and a FFP2/N95 mask (ffpm) in 12 healthy males (age 38.1 ± 6.2 years, BMI 24.5 ± 2.0 kg/m2). The 36 tests were performed in randomized order. The cardiopulmonary and metabolic responses were monitored by ergo-spirometry and impedance cardiography. Ten domains of comfort/discomfort of wearing a mask were assessed by questionnaire. Results The pulmonary function parameters were significantly lower with mask (forced expiratory volume: 5.6 ± 1.0 vs 5.3 ± 0.8 vs 6.1 ± 1.0 l/s with sm, ffpm and nm, respectively; p = 0.001; peak expiratory flow: 8.7 ± 1.4 vs 7.5 ± 1.1 vs 9.7 ± 1.6 l/s; p < 0.001). The maximum power was 269 ± 45, 263 ± 42 and 277 ± 46 W with sm, ffpm and nm, respectively; p = 0.002; the ventilation was significantly reduced with both face masks (131 ± 28 vs 114 ± 23 vs 99 ± 19 l/m; p < 0.001). Peak blood lactate response was reduced with mask. Cardiac output was similar with and without mask. Participants reported consistent and marked discomfort wearing the masks, especially ffpm. Conclusion Ventilation, cardiopulmonary exercise capacity and comfort are reduced by surgical masks and highly impaired by FFP2/N95 face masks in healthy individuals. These data are important for recommendations on wearing face masks at work or during physical exercise.

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Wearing face masks reduce the maximum physical performance. Sports and occupational activities are often associated with submaximal constant intensities. This prospective crossover study examined the effects of medical face masks during constant-load exercise. Fourteen healthy men (age 25.7 ± 3.5 years; height 183.8 ± 8.4 cm; weight 83.6 ± 8.4 kg) performed a lactate minimum test and a body plethysmography with and without masks. They were randomly assigned to two constant load tests at maximal lactate steady state with and without masks. The cardiopulmonary and metabolic responses were monitored using impedance cardiography and ergo-spirometry. The airway resistance was two-fold higher with the surgical mask (SM) than without the mask (SM 0.58 ± 0.16 kPa l−1 vs. control [Co] 0.32 ± 0.08 kPa l−1; p < 0.01). The constant load tests with masks compared with those without masks resulted in a significantly different ventilation (77.1 ± 9.3 l min−1 vs. 82.4 ± 10.7 l min−1; p < 0.01), oxygen uptake (33.1 ± 5 ml min−1 kg−1 vs. 34.5 ± 6 ml min−1 kg−1; p = 0.04), and heart rate (160.1 ± 11.2 bpm vs. 154.5 ± 11.4 bpm; p < 0.01). The mean cardiac output tended to be higher with a mask (28.6 ± 3.9 l min−1 vs. 25.9 ± 4.0 l min−1; p = 0.06). Similar blood pressure (177.2 ± 17.6 mmHg vs. 172.3 ± 15.8 mmHg; p = 0.33), delta lactate (4.7 ± 1.5 mmol l−1 vs. 4.3 ± 1.5 mmol l−1; p = 0.15), and rating of perceived exertion (6.9 ± 1.1 vs. 6.6 ± 1.1; p = 0.16) were observed with and without masks. Surgical face masks increase airway resistance and heart rate during steady state exercise in healthy volunteers. The perceived exertion and endurance performance were unchanged. These results may improve the assessment of wearing face masks during work and physical training.

Objective: Subclinical chronic inflammation could be a unifying factor linking type 2 diabetes (T2D) and atherosclerosis. The beneficial effects of physical activity on a reduced risk of coronary heart disease could at least in part be mediated by improved markers of inflammation. Research design and methods: The aim of this study was to determine the effect of 4 weeks of physical training on plasma concentrations of interleukin (IL)-6, C-reactive protein (CRP), adiponectin and IL-10 in 60 individuals with normal glucose tolerance, impaired glucose tolerance (IGT) or T2D. Results: In patients with IGT and T2D, significant improvement in body fat, fitness level, glucose metabolism and insulin sensitivity after 4 weeks of physical training was associated with significantly improved plasma concentrations of adiponectin and CRP, but not IL-6. Regression analysis demonstrated only for the anti-inflammatory parameters adiponectin and IL-10 a significant relationship with the decrease in fasting plasma glucose, whereas changes in IL-6 and CRP were not significantly related to changes in fasting plasma glucose, body fat, maximal oxygen uptake, or insulin sensitivity. In a multivariate linear regression analysis, only changes in circulating adiponectin, fasting plasma glucose and percentage body fat were determinants of changes in insulin sensitivity. Conclusions: Physical training was associated with a near normalization of adiponectin and CRP plasma concentrations in subjects with IGT and T2D. Increased insulin sensitivity after training was most strongly related to changes in adiponectin plasma concentrations, in fasting plasma glucose and percentage body fat, whereas changes in IL-6, IL-10 and CRP plasma concentrations did not significantly contribute to improved insulin sensitivity.European Journal of Endocrinology 154 577-585

In CHF patients, muscle IGF-I expression is considerably reduced in the presence of normal serum IGF-I levels, possibly contributing to early loss of muscle mass. These findings are consistent with a potential role of IGF-I for skeletal muscle atrophy in CHF.

A bacteriophage typing scheme for differentiating Listeria isolates from dairy products and various other foodstuffs was developed. Sixteen selected phages isolated from both environmental sources and lysogenic strains were used for typing and, according to their lytic spectra, divided into four groups. Thus far, 41 distinct patterns of lysis were seen when this set was used in typing 57 defined reference strains, representing all five confirmed species and 16 serotypes in addition to 454 Listeria isolates of primarily foodborne origin. Overall, typability was 84.5%; i.e., a strain was lysed by at least one phage at 10Ox routine test dilution. Strains belonging to serovar 3 were mostly resistant to lysis by the phages employed. The results were highly reproducible, as determined in retyping trials several weeks later. Some phages isolated from environmental sources showed a wider lytic spectrum than did those isolated from lysogenic strains. In accordance with this, the phages were found in different clusters within a computer-generated linkage map. Species specificity and serovar specificity of the lytic reaction were not found. None of the phages was able to lyse strains of Listeria grayi, Listeria murrayi or Jonesia denitrificans. This phage typing system may provide important information for a means of recognizing and eliminating sources of contamination by Listeria spp. within dairy plant equipment.

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