来自美国癌症协会（the American Cancer Society）的研究报告表明“久坐的生活方式增加大肠癌患者的死亡率”，究其原因可能与久坐的大肠癌患者“心肺与肌肉功能较差，血脂、血糖较高，和体内的氧化应激（oxidative stress）水平较高等有关。据此，专家们建议大家在日常生活中要留给自己适当的体育活动（physically active）时间（注：每周至少分3或4次完成150分钟的有氧运动，如散步、游泳等），以改善心肺功能和糖、脂代谢等，进而有利于维护自己的健康。

Too Much Sitting May Lower Odds of Surviving Colon Cancer

Study also found that staying active reduced the risk of dying

TUESDAY, Jan. 22 (HealthDay News) -- People diagnosed with colorectal cancer who spend a lot of their leisure time sitting have a higher risk of dying, according to researchers at the American Cancer Society.

People who are physically active, however, have a better chance of surviving than those who aren't, the researchers said.

"One factor might be that people who are physically active might be developing a less aggressive tumor," said lead researcher Peter Campbell, director of the society's Tumor Repository.

In addition, being physically fit may help people as they undergo treatment, he said.

Exercise improves cardiovascular and muscle fitness, lowers blood pressure and cholesterol, and improves blood sugar, Campbell noted. "Some of these factors would lead quite clearly to better tolerance for getting through surgery or other treatments," he said.

Campbell said the connection between sitting and dying isn't well understood.

"The sitting time is a little more speculative," Campbell said. "We do understand that sitting for long periods can lead to worse insulin and glucose profiles [measurements]. These worse insulin and glucose [measurements] can feed a tumor and increase risk of recurrence and death."

There is also evidence that long periods of sitting increases "oxidative stress" on the body's cells and worsens hormone balances, he added.

The new results need to be replicated before they can be considered definitive, but they are consistent with what is seen in non-cancer patients, Campbell said. Although the study suggests an association between exercise and better outcomes, it did not prove cause and effect. Many studies, however, have found this association not only for cancer, but for heart disease and other conditions.

Moreover, the benefits of exercise in maintaining normal body weight and improving strength and endurance are indisputable and add to overall health, Campbell said.

The report was published Jan. 22 in the Journal of Clinical Oncology.