Marathons can be bad for your health, scientists have warned after a study found 80 percent of competitors suffer kidney injury because of dehydration¹.

科学家警告称，马拉松可能会对人体产生危害。他们的研究发现，由于缺水，百分之八十的马拉松比赛选手都患有肾功能损伤。

Researchers said that although the kidneys of the participants in the 26.2 mile race fully recovered within two days, their findings raise questions concerning the potential long-term impact at a time when marathons are increasing in popularity.

研究人员称，尽管参赛者跑完26.2英里（42公里）后，他们的肾脏两天内就能完全恢复正常，但如今马拉松比赛日渐流行，研究结果引起了人们对于马拉松长期潜在影响的担忧。

The findings were published by the American Journal of Kidney Diseases, as thousands of people prepare for next month's London Marathon.

美国肾病杂志》刊登了这项研究成果。与此同时，上千人正摩拳擦掌，为下个月的伦敦马拉松赛做准备。

Previous research has shown that engaging in unusually vigorous activities - such as military training - in warm climates can damage the kidneys, but little is known about the effects of marathon running.

先前的研究表明，在气候温暖时参加过于剧烈的活动，如军事训练，会损害人的肾脏。但人们对马拉松所造成的影响则知之甚少。

A team of researchers led by Professor Chirag Parikh, of Yale University in the US, studied a small group of participants in the 2015 Hartford Marathon.

由美国耶鲁大学教授齐拉格•帕里克领导的研究小组对2015年哈特福德马拉松赛部分参赛者进行了测试。

They collected blood and urine samples before and after the event. They analysed a variety of markers of kidney injury, including serum² creatinine levels, kidney cells on microscopy, and proteins in urine.

在比赛前后，他们分别收集了受试者的血样和尿样。他们检测了各种肾脏损伤标志物，包括血清肌酐水平，显微镜下的肾细胞和尿液中的蛋白质。

The researchers found that 82 percent of the runners that were studied showed Stage 1 Acute Kidney Injury (AKI) soon after the race. AKI is a condition in which the kidneys fail to filter waste from the blood.

研究人员发现，82％的受试者在比赛结束后不久就显示出了第一阶段急性肾损伤（AKI）的症状，也就是说，肾脏无法从血液中过滤废物。

Prof Parikh said: "The kidney responds to the physical stress of marathon running as if it's injured, in a way that's similar to what happens in hospitalised patients when the kidney is affected³ by medical and surgical⁴ complications."

帕里克教授说：“马拉松会对参赛者的身体造成巨大负担，肾脏会因此做出反应，如同受伤一样，他们的肾脏状况与受到药物影响和产生手术并发症时的状况相似。”

The researchers stated that potential causes of the marathon-related kidney damage could be the sustained rise in core body temperature, dehydration, or decreased blood flow to the kidneys that occur during a marathon.

研究人员指出，马拉松造成肾损伤的潜在原因可能是，核心体温的持续升高，缺水以及比赛过程中流经肾脏的血液减少。

While the measured kidney injury resolved within two days of running the marathon, the researchers said the study still raises questions about the effects of repeated strenuous⁵ activity over time, especially in warm climates.

尽管马拉松造成的肾损伤可在两天内痊愈，但研究人员称，这项研究对重复的过于剧烈的长时间运动，尤其是在天气温暖时剧烈运动，对人体造成的影响提出了疑问。

Prof Parikh added: "We need to investigate this further. "Research has shown there are also changes in heart function associated with marathon running.

帕里克教授补充说：“我们需要进一步研究。”已有研究显示，马拉松还会导致人的心脏功能产生一些变化。

"Our study adds to the story - even the kidney responds to marathon-related stress."

“我们的研究对此做了补充 — 连肾脏都会因马拉松造成的身体负担产生变化。”