Is your libido flagging ? If so , then a lack of sleep may be the reason why , researchers claim . A study has found a direct relationship between how much sleep a person gets and their level of desire the next day . The amount of shut-eye also affects how aroused they will become . The study , involving 171 women , showed that each additional hour of sleep increased the likelihood of sexual activity with a partner by 14 per cent . Poor sex drive ? Getting more sleep is directly linked with an increase in libido , new research has shown . Sleep was also important for genital arousal , according to the research , published in the Journal of Sexual Medicine . Specifically , women who slept longer experienced fewer problems with vaginal arousal than those who obtained less sleep . 'The influence of sleep on sexual desire and arousal has received little attention in the field , ' said Dr David Kalmbach , of the University of Michigan . 'But these findings indicate that insufficient sleep can decrease sexual desire and arousal for women . He added : ' I think the take-home message should not be that more sleep is better , but that it is important to allow ourselves to obtain the sleep that our mind and body needs . ' And it 's not just women - previous research found men with poor sleep patterns have significantly lower levels of testosterone , which results in a lack of sex drive . Experts say that reduced levels of the hormone can bring a host of other negative consequences for young men , including reduced libido and poor reproduction . They can fail to build enough strength through muscle mass and bone density , leading to low energy levels , poor concentration and fatigue . Low testosterone levels are also linked to the metabolic syndrome - a cluster of metabolic risk factors that increase the chances of developing heart disease , stroke , and type 2 diabetes . Scientists from the University of Chicago found men who get less than five hours sleep a night for a week or longer suffer have far less levels of testosterone than those who get a good night 's rest . The study showed that each additional hour of sleep increased the likelihood of sexual activity with a partner by 14 per cent - and increased levels of arousal . Their study found that the levels of the hormone are reduced dramatically to levels more akin to someone 15 years older . 'Low testosterone levels are associated with reduced wellbeing and vigour , which may also occur as a consequence of sleep loss , ' said Professor Eve Van Cauter , who led the study . Other reasons for low libido include poor diet , being overweight and low iron levels . An estimated one in four British women doesn ’ t get enough iron from their diet , and iron deficiency is known to leave your libido lagging , says Dr Radha Modgil , a GP in West London with a special interest in sexual health . ‘ Low iron levels are thought to reduce the quality of blood flow and so sap energy , ’ she explains . ‘ If you ’ re exhausted , sex is obviously the last thing you feel like doing. ’ ‘ The best source of easily absorbable iron is a nice juicy steak , ’ adds dietitian Helen Bond . ‘ Red meat like steak helps release key amino acids from the brain which are important for good mood. ’ Other reasons for low libido include poor diet , being overweight and low iron levels . Dietitians say red meat such as steak is a good , easy-absorbed form of iron . ‘ Red meat is also a good source of B vitamins , which help convert the carbohydrates we eat into energy . It ’ s also a rich source of zinc , important for the production of the sex hormone testosterone , which women also need for sexual desire . Other good sources of zinc include beans , nuts and oysters. ’ Eating too much white bread and other refined carbohydrates can sap your sex drive , says Helen Bond . ‘ Foods such as white bread release the sugar more quickly than their wholegrain counterparts — and too much sugar is associated with energy slumps , which mean you won ’ t have the energy for sex , ’ she adds . Too much sugar also makes you fat , raising the level of oestrogen in the body , in turn reducing testosterone levels in men , says gynaecologist Peter Bowen-Simpkins , . ‘ If you ’ re obese , you feel less attractive . You also have reduced blood flow to the sex organs . ’
Each additional hour of sleep increased the likelihood of sexual activity with a partner by 14 per cent , say the University of Michigan researchers . The amount of shut-eye also affects how aroused women will become . Previous research has found men lacking in sleep have poorer libidos .