WEBVTT - Why can't a couch potato run a marathon?

0:00:00.520 --> 0:00:03.400
<v Speaker 1>Welcome to brain Stuff from house stuff marks dot com

0:00:03.600 --> 0:00:14.320
<v Speaker 1>where smart happens. Hi, I'm muscle brain with today's question

0:00:14.600 --> 0:00:17.759
<v Speaker 1>why can a trained athlete run a marathon but a

0:00:17.840 --> 0:00:21.439
<v Speaker 1>couch potato can't run half a mile? If you're out

0:00:21.440 --> 0:00:24.400
<v Speaker 1>of shape, you know it. Even climbing a flight of

0:00:24.480 --> 0:00:27.080
<v Speaker 1>stairs can leave you out of breath if you haven't

0:00:27.120 --> 0:00:31.280
<v Speaker 1>been exercising regularly. Even a little exercise like going up

0:00:31.320 --> 0:00:34.480
<v Speaker 1>the steps can put a strain on your body. Your

0:00:34.520 --> 0:00:38.720
<v Speaker 1>body responds to exercise with a coordinated effort that involves

0:00:38.800 --> 0:00:43.120
<v Speaker 1>many systems, including your muscles, your heart, your lungs, your

0:00:43.159 --> 0:00:46.839
<v Speaker 1>blood vessels, your skin, your brain, and several others. When

0:00:46.920 --> 0:00:51.680
<v Speaker 1>you do exercise, all those systems are working together. For example,

0:00:52.000 --> 0:00:55.760
<v Speaker 1>the muscles provide the strength, power and endurance to do

0:00:55.880 --> 0:01:01.200
<v Speaker 1>the exercise. Enzymes within those muscles mobile wise various fuels

0:01:01.240 --> 0:01:04.480
<v Speaker 1>to provide a t P to meet the energy demands

0:01:04.480 --> 0:01:08.120
<v Speaker 1>of the working muscle. The heart and blood vessels increase

0:01:08.240 --> 0:01:11.920
<v Speaker 1>the blood flow to deliver more oxygen to the working muscle.

0:01:12.280 --> 0:01:15.480
<v Speaker 1>The lungs increase the rate of breathing to deliver more

0:01:15.520 --> 0:01:18.800
<v Speaker 1>oxygen to the muscle. All of these systems can be

0:01:18.880 --> 0:01:23.640
<v Speaker 1>improved by training. Lack of training causes them to atrophy.

0:01:23.760 --> 0:01:27.480
<v Speaker 1>Let's compare the couch potato with the trained athlete. The

0:01:27.480 --> 0:01:32.559
<v Speaker 1>couch potato has several different problems. First, there are weakened

0:01:32.640 --> 0:01:38.559
<v Speaker 1>or atropheed muscles. Second, there's weakened or atropheed heart muscles. Third,

0:01:38.640 --> 0:01:43.800
<v Speaker 1>there's decreased metabolic enzymes in the muscles. Fourth, there's diminished

0:01:43.880 --> 0:01:47.919
<v Speaker 1>lung capacity, and fifth there are the wrong metabolic fuels.

0:01:48.320 --> 0:01:52.320
<v Speaker 1>If muscles aren't used regularly, their mass decreases, and so

0:01:52.400 --> 0:01:56.120
<v Speaker 1>does their ability to store energy. The muscle proteins and

0:01:56.240 --> 0:02:00.800
<v Speaker 1>fibers that develop the force diminished. Therefore, the couch potato

0:02:00.920 --> 0:02:04.880
<v Speaker 1>simply can't generate the force required for the physical activity

0:02:04.920 --> 0:02:08.080
<v Speaker 1>involved in running a marathon. The heart is a muscle,

0:02:08.240 --> 0:02:11.919
<v Speaker 1>just like skeletal muscle. It also adapts to a less

0:02:11.960 --> 0:02:16.040
<v Speaker 1>active state by losing muscle mass. While this doesn't affect

0:02:16.040 --> 0:02:18.520
<v Speaker 1>the couch potatoes ability to pump blood to his or

0:02:18.520 --> 0:02:22.440
<v Speaker 1>her tissues, it limits the ability to increase the blood

0:02:22.440 --> 0:02:25.880
<v Speaker 1>flow during exercise. The heart will not be able to

0:02:26.000 --> 0:02:29.799
<v Speaker 1>stretch as far or develop the pressure required to increase

0:02:29.880 --> 0:02:33.160
<v Speaker 1>the cardiac output. That's why doctors tell you that you

0:02:33.240 --> 0:02:36.440
<v Speaker 1>need to exercise regularly to keep your heart in shape.

0:02:37.000 --> 0:02:42.320
<v Speaker 1>The enzymes involved in anaerobic which means without oxygen, and aerobic,

0:02:42.400 --> 0:02:47.080
<v Speaker 1>which means with oxygen metabolism help provide the energy to

0:02:47.120 --> 0:02:50.640
<v Speaker 1>working muscle. In the couch potato, however, the level of

0:02:50.680 --> 0:02:55.160
<v Speaker 1>these enzymes goes down, so the inactive person's body can't

0:02:55.200 --> 0:02:59.360
<v Speaker 1>metabolize fuel as well as an athlete's body can. The

0:02:59.480 --> 0:03:04.680
<v Speaker 1>fuels used in the body during exercise mainly come from carbohydrates, glucose,

0:03:05.080 --> 0:03:09.880
<v Speaker 1>muscle glycogen, and some fat. However, the couch potato has

0:03:10.000 --> 0:03:14.040
<v Speaker 1>mostly fat and probably little glycogen available in the muscles.

0:03:14.400 --> 0:03:17.680
<v Speaker 1>It takes longer to metabolize fat as a fuel than

0:03:17.760 --> 0:03:21.880
<v Speaker 1>it takes to metabolize glycogen. That means that the breakdown

0:03:21.919 --> 0:03:24.880
<v Speaker 1>of fat can't keep pace with the energy demands of

0:03:24.919 --> 0:03:29.320
<v Speaker 1>working muscle. All of these different factors combined to limit

0:03:29.360 --> 0:03:32.680
<v Speaker 1>the ability of the couch potato to exercise. The good

0:03:32.680 --> 0:03:36.440
<v Speaker 1>news is that with a moderate exercise program, the couch

0:03:36.480 --> 0:03:40.400
<v Speaker 1>potato or anyone else, can improve their fitness and their

0:03:40.440 --> 0:03:43.840
<v Speaker 1>bodies response to exercise at least enough to do a

0:03:43.920 --> 0:03:48.600
<v Speaker 1>ten k run. Be sure to check out our new

0:03:48.680 --> 0:03:52.000
<v Speaker 1>video podcast Stuff from the future. Join House to Work

0:03:52.080 --> 0:03:55.600
<v Speaker 1>staff as we explore the most promising and perplexing possibilities

0:03:55.640 --> 0:03:59.280
<v Speaker 1>of tomorrow. The House to Works I Find app has

0:03:59.320 --> 0:04:01.800
<v Speaker 1>a Rye Dowlet. It today on iTunes