Walking-like swimming，bicycling and running--is an aerobic exercise，(31)___builds the capacity for energy output and physical endurance by increasing the supply of oxygen to skin and exercises may be a primary factor in the(32) ___0f heart and circulatory disease.
As probably the least strenuous，safest aerobic activity，walking is the(33) ___acceptable exercise for the largest number of ing(34) ___comfortable speed improves the efficiency of the cardio respiratory system(35) ___stimulating the lungs and heart，but at a more gradual rate(36) ___most other forms of exercise.
In one test，a group of men 40 t0 57 years of age，(37) ___at a fast pace for 40 minutes four days a week，showed improvement(38) ___to men the same age on a 30 minute，three—day—a—week jogging program in the same r resting heart rate and body fat decreased(39) ___e changes suggest(40) ___of the important-even vital--benefits walking can(41) ___about.
Walking(42) ___burns takes 3，500 calories to gain or(43) ___0ne e a walk at a moderate pace will(44) ___up 300 t0 360 walking one hour every other day，you Can burn up a pound—and—a—half monthly，or l8 pounds(45) ___-providing there is no change in your in-take of (46).___weight faster，walk an n hour every day and bum up 3 pounds a month，or 36 pounds a year.
(47) ___your age，right now is the time to give your physical well-being as much thought as you(48) ___to pensions or ing is a vital defense(49) ___the ravages of degenerative diseases and is nature’s (50) ___of giving you a tuneup.
參考譯文：
行走就像游泳、騎自行車和跑步一樣，是一種有氧運動，可以通過給面板和肌肉增加供氧而塑造更大的肺活量和耐力。這樣的運動可能是防止心臟和血液迴圈疾病的一個主要因素。
作為可能是最不費力氣、最安全的有氧運動，絕大多數人認為行走可以接受。以舒適的速度行走可以通過啟用肺部和心臟增強心肺系統的效率，但比起大多數其他的鍛鍊形式，行走的速度更為舒緩。
在一項測試中，一組40到57歲的'男子每週4天快速行走40分鐘，與同樣年齡每週同期進行3次30分鐘慢跑的男子收到了同樣的改善效果。他們的正常心率和身體脂肪明顯降低。這些變化表明行走可以帶來重要的，甚至是關鍵的益處。
行走也可以燃燒熱量。獲得或失去一磅重量需要消耗3 500卡熱量。因為以中等速度走一小時的路程將會消耗300到360卡的熱量。每隔一天行走一小時，則每月可以減去一磅半的脂肪，或者說一年可以減去18 磅脂肪，只要您每日攝入的食物量不變。為了更快減去體重，每天行走一小時，那麼每月就可以減去3磅脂肪，一年就是36磅。
不管您的年齡有多大，現在都應該花同樣時間考慮身體和養老金或保險。行走是一種關鍵的抵禦疾病和抗衰老的方法。它是自然界給您的一種調整的方式。
