The differences between gents and ladies change the growth https://kissbrides.com/brazilian-women/natal/ of move, brand new regulation regarding lung regularity, the stress swings while the following performs regarding respiration.
But not, zero difference is offered involving the sexes whenever WOB is versus other percentages out of maximum oxygen consumption (V?
Females’ quicker airways diameter and you may lung frequency cause all the way down height expiratory disperse and essential potential. One issues was feminine possess a smaller maximum move–volume circle. Their ability to make enhanced ventilation during exercise is, ergo, smaller with respect to dudes. This might predispose female so you can developing expiratory flow restriction (EFL). EFL occurs when the flow–regularity circle out of an excellent tidal air superimposes otherwise is higher than the brand new expiratory border of one’s maximum circulate–frequency contour. It includes expiratory move that can’t become then improved by improving the energy of expiratory muscles, getting maximumal at this tidal volume . Yards c C laran ainsi que al. earliest figured the smaller lung volumes and maximal disperse pricing in women grounds increased prevalence off EFL, which have tidal regularity and you may minute ventilation are mechanically limited from the highest work. This will be especially apparent during the very match feminine inside last stage away from exercise [51, 52].
The regulation of lung volume during exercise is an important factor as it reflects the strategy by which tidal volume is achieved and it contributes to the work of breathing. Normally, the increased tidal volume during exercise is a consequence of an end-inspiratory lung volume increase and an end-expiratory lung volume (EELV) decrease with respect to the resting values. The reduction in EELV is similar between men and women throughout the majority of submaximal exercise and/or at a certain level of minute ventilation [52, 53]. By contrast, healthy fit women show a relative hyperinflation during heavy exercise and a higher rate of ventilation [50, 51]. This means that EELV increases at peak exercise. Specifically, dynamic hyperinflation occurs at the onset of significant EFL. It seems, therefore, that operational volume at maximal exercise depends on the presence or absence of EFL . In fact, when EFL is reduced by He–O2 (79% He–21% O2) breathing EELV is maintained lower than baseline . The presence of EFL during heavy exercise in healthy trained subjects, therefore, seems to trigger a reflex response that makes EELV increase to avoid dynamic compression of the airway downstream from the flow-limited segment . The operational lung volume, therefore, shifts towards higher volume.
Hyperinflation, ergo, could possibly get result in breathing muscles tiredness since it helps to make the inspiratory human body package out-of a shorter length as well as in the presence of faster lung conformity [50, 52].
The combination of EFL and dynamic hyperinflation makes the work of breathing (WOB) and oxygen cost of hyperpnoea increase. Women, in fact, show a higher WOB than men across a range of ventilations during progressive exercise. It even becomes twice that of men when ventilation is above 90 L?min ?1 [51, 55]. O2max), although women have ?25% lower minute ventilation than their male counterparts. V?O2max is distributed among all the skeletal muscles, its relationship with the work performed being linear. D ominelli et al. demonstrated that this is also valid for the respiratory muscles that are morphologically and functionally skeletal muscles. They computed the oxygen uptake of the respiratory muscles (V?O2RM) over a wide range of minute ventilations, showing that the greater WOB in women is linearly associated with higher V?O2RM with less efficiency than men at submaximal and maximal exercise intensities. Women, in fact, are characterised by greater V?O2RM for a given WOB and ventilation, with V?O2RM representing a significantly greater fraction of whole-body oxygen consumption in women (?13.8%) than in men (?9.4%) . It can be speculated that a proportionally greater fraction of blood flow corresponds to the increased V?O2RM in women. This will possibly lead to an important competition for blood flow between respiratory and working muscles, particularly during heavy exercise [15, 50].