The age-old riddle of why many women live longer than men has been solved. It's their pumping power, British researchers have found.

    On average, women live five years longer than men and women over the age of 60 are now the fastest-growing section of the British population.

    The average male heart becomes weaker with age, and by the age of 70 its power to pump blood around the body could have decreased by up to a quarter of its youthful strength.

    David Goldspink, Professor of Cell and Molecular Sports Science at Liverpool John Moores University, said that women's longevity is linked to the strength of their hearts. Unlike men, they pump just as strongly at 70 as they do at 20.

    "We have found that the power of the male heart falls by 20-25 per cent between 18 and 70 years of age," Professor Goldspink said. "In stark contrast, over the same period there was no age-related decline in the power of the female heart, meaning that the heart of a healthy 70-year-old woman could perform almost as well as a 20-year-old's."

    The dramatic difference between the sexes might explain why women live longer. The good news is that men of any age can improve the health of their heart simply by taking more regular exercise.

    The results are based on the findings of a two-year study of a cross-section of the British population, which examined the effects of ageing on the cardiovascular system.

    Professor Goldspink and a team of scientists at the university's Research Unit for Human Development and Ageing examined more than 250 men and women between 18 and 80.

    None of the volunteers had a weekly exercise routine and all were considered to have low fitness levels, but were otherwise healthy. Each volunteer underwent five hours of tests to measure their blood pressure and the performance of their heart while at rest and while they exercised on a treadmill.

    The researchers found that the large arteries in the body became stiffer and less elastic with age, causing increased blood pressure. Blood flow to the muscles and skin of the limbs was also found progressively to decrease. These changes were found to occur earlier in men, but women caught up soon after the menopause.

    長期以來困惑人類的難解之謎——為何多數女性比男性長壽——已經找到了答案。英國研究者們發現，原因在于心臟的供血動力。

    女性的平均壽命要比男性多5歲。而目前英國增長速度最快的人群正是60歲以上的女性群體。

    一般情況下男性的心臟隨著年齡增長而衰老。男性到了70歲時，心臟向全身供血的能力最多可能減少為年輕時的3/4。

    利物浦約翰摩爾大學的細胞及分子運動學教授大衛·葛茲平克說，女性的長壽與她們的心臟活力有關。和男性所不同的是，70歲女性的心臟和20歲時一樣強健有力。

    葛茲平克教授說：“我們已經發現男性在18到70歲之間心臟活力會衰減20%至25%。與之形成鮮明對比的是同年齡范圍的女性——沒有（任何證據）顯示老齡化可導致女性心臟衰弱，這意味著一名健康的70歲老婦和一位20歲女性的心臟幾乎可以一樣地工作。”

    這一巨大的性別差異可能就是女性為何更長壽的答案。所幸的是，任何年齡段的男性都可以改善自己的心臟健康狀況，只要他們能更經常地鍛煉。

    這些結果來源于一項為期兩年的研究。該研究對英國人口進行橫斷面分析，旨在調查年齡增長對心血管系統產生的影響。

    葛茲平克教授和一隊科學家在（約翰摩爾）大學的人類發展及老齡化研究中心調查了250多名18到80歲的男性和女性。

    這些志愿者中無人進行每周固定的體育鍛煉，健康狀況一般。每位志愿者都進行了5小時的測試，期間檢查他們在休息或在跑步機上時的血壓和心臟狀況。

    研究者們發現人體內的大動脈血管隨著年齡增長而逐漸僵硬缺少彈性，從而導致血壓上升。人體肌肉和四肢皮膚的血液循環也日益減少。這些情況首先出現在男性身上，但女性在絕經后不久也會發生。