In the battle of the sexes, new UBC research suggests that men may be stronger physically but women have much greater muscle endurance than their male counterparts. 
 
 In a new study from UBC's Okanagan campus, researchers in the School of Health and Exercise Sciences have found that women are considerably less exhausted after natural, dynamic muscle exercises than men of similar age and athletic ability. 
 
 "We've known for some time that women are less fatigable than men during isometric muscle tests -- static exercises where joints don't move, such as holding a weight -- but we wanted to find out if that's true during more dynamic and practical everyday movements," says Assistant Professor Brian Dalton. "And the answer is pretty definitive: women can outlast men by a wide margin." 
 
 In his study, done in collaboration with the University of Guelph and University of Oregon, Dalton recruited eight men and nine women that were at a similar level of physical fitness. Participants were asked to flex their foot against a suite of sensors as quickly as they could 200 times. The speed, power and torque of their movements and electrical activity of their muscles was then captured and recorded over time. 
 
 "We chose to measure foot movements because it makes use of calf muscles on the back of the leg, which are essential for practical, everyday tasks like standing and walking," says Dalton. "What we found is that males were faster and more powerful at first but became more fatigued much faster than females." 
 
 While only one isolated muscle group was studied, Dalton says he would expect similar results for other muscles groups and his results are consistent with what has been observed elsewhere. 
 
 "We know from previous research that for events like ultra-trail running, males may complete them faster but females are considerably less tired by the end," he adds. "If ever an ultra-ultra-marathon is developed, women may well dominate in that arena." 
 
 But it's not all about competition. Dalton says his results can also inform more practical applications, such as designing exercise programs or even adapting work environments to minimize work-related fatigue and improve overall productivity. 
 
 "We may, for example, want to lower the load for males, even though they may be stronger at the outset, to more closely match the endurance observed in females," he says. "Both sexes have valuable physical abilities and it only makes sense that we study and develop the tools to afford them the best advantage." 
 
 "There's no battle at all," he jokes. "Maybe more of a balance of the sexes." 
 
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 The study appears in the June 2017 issue of Applied Physiology, Nutrition, and Metabolism and was conducted with financial support from Natural Sciences and Engineering Research Council of Canada. 
 
 Media Contact: 
 
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 The University of British Columbia | Okanagan campus 
 
 Phone: 250-807-9926 | Cell: 778-628-3093 
 
 Email: nathan.skolski@ubc.ca ||||| Elderly women are more likely than elderly men to develop Alzheimer's disease, even when they are exposed to some of the same risk factors, two new studies find. 
 
 Senior women who have mild cognitive problems, such as memory impairment and difficulties with language or thinking skills, decline in cognitive ability twice as fast as men who also have mild cognitive impairment, according to one study. 
 
 A separate study found that women declined more dramatically than men in measures of cognition, function and brain size after they underwent surgery and general anesthesia. Both studies, which have yet to be published in scientific journals, were presented at the 2015 Alzheimer's Association International Conference, held July 18 to 23 in Washington, D.C. 
 
 People with mild cognitive problems can still function in everyday life, but their declines, though slight, can be noticeable in typical conversations, the researchers said. Moreover, people with mild cognitive impairments have an increased risk of developing Alzheimer's disease or another form of dementia, they added. [10 Ways to Keep Your Mind Sharp] 
 
 In the first study, scientists studied a group of 400 people with mild cognitive impairment, and examined how their cognitive abilities changed over an eight-year period. To measure cognitive ability, each participant underwent a cognitive exam with 11 parts that were scored on a scale from 0 to 70. 
 
 The women did not fare well overall, the researchers found. Men with mild cognitive problems declined an average of 1.05 points per year, whereas women declined an average of 2.3 points per year, they said. 
 
 Both men and women declined more quickly if they had a specific gene variant, called ApoE4, that is associated with an increased Alzheimer's risk. But after the researchers factored in ApoE4 status, as well as age, education, baseline cognition score and follow-up time, women were still more likely to cognitively decline at a faster rate than men, the scientists said. 
 
 "Our findings suggest that men and women at risk for Alzheimer's may be having two very different experiences," study researcher Katherine Lin, a clinical research scholar of Alzheimer’s disease at Duke University Medical Center in Durham, North Carolina, said in a statement. "These results point to the possibility of as-yet-undiscovered gender-specific genetic or environmental risk factors that influence the speed of decline. Uncovering those factors should be a high priority for future research." 
 
 Anesthesia and surgery 
 
 Elderly women also have a greater risk of developing Alzheimer's than men if they've had surgery and general anesthesia, the other study found. 
 
 Most people who receive general anesthesia and undergo surgery show no lasting cognitive impairments afterward, the researchers said. However, previous studies have shown that elderly people are at increased risk for long-term cognitive and functional problems after having surgery and general anesthesia, said lead researcher Dr. Katie Schenning, an assistant professor of anesthesiology and perioperative medicine at Oregon Health & Science University in Portland. 
 
 "When I started learning more about the sex differences that exist in Alzheimer's in general, it made me curious as to whether there might be a sex difference in the effects of anesthesia and surgery on cognitive decline," Schenning told Live Science. 
 
 To investigate, she and her colleagues looked at volunteers in two research groups — the Oregon Brain Aging Study and the Intelligent Systems for Assessing Aging Changes. In total, the study included 527 participants, including 182 individuals who underwent 331 procedures with general anesthesia. 
 
 Surgery with general anesthesia was associated with long-term cognitive declines in both elderly men and elderly women, the researchers found. 
 
 However, elderly women who experienced surgery and general anesthesia declined more quickly than elderly men on measures of cognition, the ability to function in everyday life and brain volume (meaning women tended to develop larger ventricles in their brain, which is an indication of brain atrophy), Schenning said. [6 Foods That Are Good for Your Brain] 
 
 Women who received multiple surgeries with general anesthesia showed even greater declines, Schenning added. What's more, people showed faster declines in these measures of brain function if they received surgery with general anesthesia and had at least one ApoE4 gene variant, she said. 
 
 Nonetheless, the evidence is too preliminary to advise the elderly against getting general anesthesia and surgery, she said. 
 
 "We don't know if this is anesthesia or surgery, or a combination thereof," Schenning said. Instead, she advised elderly people at risk for Alzheimer's to minimize their elective or unnecessary surgeries in which general anesthesia is needed. 
 
 Studies such as these may help researchers understand why nearly two-thirds of American seniors with Alzheimer's disease are women, said Maria Carrillo, chief scientific officer of the Alzheimer’s Association. 
 
 "Women are disproportionately affected by Alzheimer's, and there is an urgent need to understand if differences in brain structure, disease progression and biological characteristics contribute to higher prevalence and rates of cognitive decline," Carrillo said in a statement. "To intervene and help reduce the risk of Alzheimer's, it's critical to understand the reasons for these differences." 
 
 Follow Laura Geggel on Twitter @LauraGeggel. Follow Live Science @livescience, Facebook & Google+. Original article on Live Science. ||||| Women who display the early signs of mental decline that can precede Alzheimer’s disease deteriorate faster than men with the same condition, a new study has found. 
 
 Another study suggests that women’s daily activities and cognitive abilities decline faster than men’s after undergoing surgery with general anesthesia. A third study has found that an abnormal protein that plays a key role in triggering Alzheimer’s accumulates at higher rates in women’s brains than in men’s. 
 
 The new research, presented this week at the Alzheimer’s Association International Conference in Washington, lends additional support to the view that women run a higher risk than men of developing Alzheimer’s disease and may be more vulnerable to its damaging effects once the illness gets going. 
 
 “The bottom line is, more and more we think there are some differences,” said Kristine Yaffe, a professor of psychiatry, neurology and epidemiology at the University of California at San Francisco. “It’s not just that women are living to be older — that’s true, and that drives some of this. But there’s something else going on in terms of biology [and] environment for women compared to men that may make them at greater risk or, if they have some symptoms, may change the progression.” 
 
 [Here’s a look at why women may be more at risk for Alzheimer’s than men] 
 
 Of an estimated 5.4 million people with Alzheimer’s in the United States, about 3.4 million are female. Women have twice the lifetime risk of developing Alzheimer’s disease, which is the leading cause of dementia. The disease is progressive and incurable. 
 
 The distinguishing features of Alzheimer’s include the buildup of abnormal proteins that destroy brain cells in areas critical to memory and learning. These proteins — beta-amyloid, which forms waxy, insoluble plaques; and tau, which creates fibrous tangles — begin accumulating well ahead of symptoms such as memory loss, and advances in technology have allowed scientists to obtain images of them. 
 
 For a year or more, the Alzheimer’s Association has highlighted the disease’s disparate impact on women, both in its incidence and in the burden of caring for those who have it. The findings shared Tuesday bolster the theory that gender differences may have an effect on determining Alzheimer’s risk, perhaps because of hormonal interactions with genes, biochemistry and development in the brain. 
 
 [How fear of Alzheimer’s reshapes some people’s lives] 
 
 Roberta Diaz Brinton, a professor at the University of Southern California’s School of Pharmacy, said her research has shown that women may have higher Alzheimer’s risk because estrogen has such an important effect on regulating the energy supply in the brain. At menopause, women’s bodies undergo radical transformations that can alter the brain’s ability to change glucose, a kind of sugar, into energy. 
 
 “Every cell — every single cell in your body — has a sex. The X chromosome or the XY chromosome is within all of our cells, and that very likely has an effect on cell function,” said Brinton, who helped organize the Alliance of Women Alzheimer’s Researchers, a professional interest group within the Alzheimer’s Association. 
 
 A study led by scientists at UC San Francisco explored the connection between gender and a gene whose ability to raise the risk of developing Alzheimer’s disease is already well known. The study — conducted by Duygu Tosun, an assistant professor of radiology, and others — used data from brain scans to investigate links between gender and a gene variant known as APOE4. 
 
 The gene is one of several variants that code for an apolipoprotein, a protein that shuttles cholesterol and fatty substances in the body and the brain. Having a single copy of the gene raises the risk of Alzheimer’s at least twofold; having a copy from each parent boosts the odds even higher. 
 
 The study found that men who carried the APOE4 gene had higher accumulations of beta-amyloid in their brains than men who did not. But the study’s major finding was that women had higher accumulations of the abnormal protein in their brains, regardless of whether they carried the APOE4 gene. 
 
 “This study shows women have more amyloid in their brain than men in general, and especially once the women are in the late stages where they’re having dementia. They’re going to have higher levels than men, and the APOE4 isn’t going to affect that,” said Michael W. Weiner, a radiology professor at UC San Francisco and principal investigator of the Alzheimer’s Disease Neuroimaging Initiative. 
 
 That heightened vulnerability may also affect the rate of decline among women who already show signs of dementia. 
 
 Katherine Amy Lin, an undergraduate at Duke University, said her team used data from the neuroimaging initiative to track the erosion of cognitive ability in men and women who already suffered mild cognitive impairment. 
 
 Lin, who worked with the university’s medical school, said the study examined 257 men and 141 women, mostly in their mid-70s, and their performance on cognitive tests over an eight-year period. 
 
 The study found that people with the APOE4 gene had a faster rate of decline. But after adjusting for genetic disposition and other factors, the study showed that women who suffered from mild cognitive decline saw their performance deteriorate twice as fast as men’s. 
 
 “Our findings do suggest that there is greater vulnerability to women,” Lin said. She cautioned, however, that the results are preliminary and in need of further gender-specific research. 
 
 In a similar study, Katie J. Schenning, a physician at Oregon Health & Science University in Portland, said her team explored gender differences in people who suffer cognitive decline after undergoing surgery with general anesthesia. Though most people do not experience any lasting effects from surgery involving anesthesia, recent research has found that older people are susceptible to progressive cognitive and functional decline after such procedures. Older adults receive about a third of the anesthesia administered in the United States, Schenning said. 
 
 Using data from the Oregon Brain Aging Study and a project called Intelligent Systems for Assessing Aging Changes, the team looked at 527 people, including 182 who underwent 331 procedures using general anesthesia. The average follow-up was seven years. It found that men who were exposed to general anesthesia during surgery declined faster on measures of cognitive performance and daily activity than men who had not had surgery; women who underwent surgery with anesthesia also declined faster than women who did not. But women also declined more rapidly than men. The rate was even faster for women who had multiple surgeries using anesthesia. 
 
 Women had more rapid erosion in measures of both cognition and ability to perform daily activities. 
 
 “I do want to stress that, at this time, it’s uncertain which specific surgical or anesthetic factors might contribute to postoperative cognitive or functional decline,” Schenning said. “It’s also very important to note that this is just not an effect of anesthesia itself but rather a combination of the effects of anesthesia and surgery together.” 
 
 But Schenning also said the findings suggest that physicians should advise older patients of the risk of decline after surgery with a general anesthetic and perhaps urge them to carefully weigh whether to undergo nonessential procedures.
– Guys might be good at carrying heavy furniture but they tire faster than their female counterparts, new research out of the University of British Columbia shows. "We've known for some time that women are less fatigable than men during isometric muscle tests—static exercises where joints don't move, such as holding a weight—but we wanted to find out if that's true during more dynamic and practical everyday movements," says UBC researcher Brian Dalton in a press release. "And the answer is pretty definitive: women can outlast men by a wide margin." Collaborating with the University of Guelph and University of Oregon, the researchers report in the journal Applied Physiology, Nutrition, and Metabolism that a handful of men and women were asked to flex their foot against sensors as fast as they could 200 times. Those sensors captured several metrics, including speed, power, torque, and even electrical activity in their muscles. The men were both faster and more powerful, but they also became more fatigued "much faster" than the women. Dalton notes that in ultra-trail running, men tend to be faster, but women tend to be far less tired; in fact in Outside, one runner calls for separate goals for women. "If ever an ultra-ultra-marathon is developed, women may likely dominate," Dalton says. But as for the Mars-vs.-Venus battle, Dalton jokes, "there's no battle at all. Maybe more of a balance of the sexes." More seriously: "Both sexes have valuable physical abilities and it only makes sense that we study and develop the tools to afford them the best advantage." (Sex gets better with age for women.)