A new US study suggests yet another reason to get some shut-eye, finding that husbands and wives who get a good night's sleep are more satisfied with their marriage the next day.Conducted by researchers from Florida State University, the study looked at the importance of sleep on self-regulation, which is the ability to move focus away from undesirable experiences when making an evaluation of a relationship, and can influence how satisfied couples are with their partner.Self-regulation requires energy, which can be can be replenished when our bodies sleep, with previous studies showing that even just partial sleep deprivation can have a negative effect on processes that require self-regulation. The researchers commented in their paper that "Up to one-third of married or cohabiting adults report that sleep problems burden their relationship."The study looked at 68 newlywed couples over a seven-day period. Each day couples were asked to record the number of hours they slept and then answer two sets of questions.The first set measured overall relationship satisfaction with questions such as, "How satisfied were you with your marriage today?"The second set looked at relationship experiences in nine areas including chores, the amount of time spent together and how the couple resolved conflict.Participants rated their answers using a scale of 1 (not satisfied at all) to 7 (extremely satisfied).The results showed that couples were more satisfied with their relationship on the days after which they had slept for a longer period of time.In addition, the team also found that husbands, although not wives, were less negatively affected by bad experiences in the nine areas assessed, and better able to remain satisfied with their relationship, when they got more sleep.The researchers did point out that the study had some limitations, including that the majority of the participants were white, had been married for less than six months, and were on average 24 years old, with the team recommending further studies in a wider variety of couples in order to draw firmer conclusions.However co-author Heather Maranges commented that, "The universality of our findings is important. That is, we know all people need sleep. Regardless of the stage at which a couple is in their relationship or the cultural context in which they're embedded, each member of the couple can be adversely affected by not getting enough sleep."The results can be found published online in the Journal of Family Psychology.