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Medicine Science

Scientists Study How Little Exercise You Need 437

Hugh Pickens writes "Millions of Americans don't engage in much exercise, if they complete any at all and asked why, a majority of respondents, in survey after survey, say, 'I don't have time.' Now Gretchen Reynolds reports that instead of wondering just how much exercise people really need in order to gain health and fitness, a group of scientists in Canada are turning that issue on its head and asking, how little exercise do we need to maintain fitness and the answer appears to be, a lot less than most of us think — provided we're willing to work a bit. Most people have heard of intervals, or repeated, short, sharp bursts of strenuous activity, interspersed with rest periods. Almost all competitive athletes strategically employ a session or two of interval training every week to improve their speed and endurance. Researchers have developed a version of high-intensity interval training (HIIT) that involves one minute of strenuous effort, at about 90 percent of a person's maximum heart rate (which most of us can estimate, very roughly, by subtracting our age from 220), followed by one minute of easy recovery. The effort and recovery are repeated 10 times, for a total of 20 minutes and the interval training is performed twice a week. Despite the small time commitment of this modified HIIT program, after several weeks of practicing it, both the unfit volunteers and the cardiac patients showed significant improvements in their health and fitness. 'A growing body of evidence demonstrates that high-intensity interval training can serve as an effective alternate to traditional endurance-based training, inducing similar or even superior physiological adaptations in healthy individuals and diseased populations, at least when compared on a matched-work basis.'"
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Scientists Study How Little Exercise You Need

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  • Re:Define FItness (Score:5, Informative)

    by Suddenly_Dead ( 656421 ) on Wednesday February 15, 2012 @09:51PM (#39054635)

    Define Fitness


    Despite these differences, both protocols induced similar increases (P < 0.05) in mitochondrial markers for skeletal muscle CHO (pyruvate dehydrogenase E1alpha protein content) and lipid oxidation (3-hydroxyacyl CoA dehydrogenase maximal activity) and protein content of peroxisome proliferator-activated receptor-gamma coactivator-1alpha. Glycogen and phosphocreatine utilization during exercise were reduced after training, and calculated rates of whole-body CHO and lipid oxidation were decreased and increased, respectively, with no differences between groups (all main effects, P < 0.05).

  • by John Hasler ( 414242 ) on Wednesday February 15, 2012 @09:57PM (#39054691) Homepage

    Not unless you have a serious heart condition. It is impossible for a healthy person (no matter how unfit) to injure his heart by working it hard.

    Interval training is excellent. I do roughly what the article describes every other day (on the other days I just run two miles). This keeps my blood pressure below 120 and my resting heart rate in the low fifties.

  • by Baldrson ( 78598 ) * on Wednesday February 15, 2012 @10:11PM (#39054825) Homepage Journal
    Most of the /. readers are concerned about age-related cognitive decline -- either that or they've already declined cognitively to the point that they should forget about /. and turn on the TV.

    The best way, currently known, to slow age-related cognitive decline is exercise because it produces Brain Derived Neurotrophic Factor.

    But did TFA even mention BDNF?


    Maybe the author should exercise more.

  • Re:Interval Training (Score:4, Informative)

    by cmarkn ( 31706 ) on Wednesday February 15, 2012 @10:34PM (#39055031)

    This shows a complete lack of understanding of what this training is about. In order to bang out 100 leg presses you have to be working at an extremely low intensity, and banging weights is the way to tear your muscles. High Intensity means doing one set, of very few reps, with moderately heavy weights, moving slowly and smoothly, and maintaining perfect form throughout every motion. This way there is virtually no risk of injury. And then resting for several days to allow the muscles that have been worked hard to recover and rebuild. In fact, even this a overworking; it takes only seconds at maximum capability to produce the desired effect from an exercise.

    I work out once a week, for 20 minutes at a time, and have wonderful improvement in my blood pressure and resting pulse rate in the last six months. My endurance in other activities is also improving slowly but surely. And that with no injury whatsoever, though I am sore the next day.

    Contrary to descriptions elsewhere on the page, I do no warm-ups or warm-downs, and no stretching before or after exercise. Stretching moves muscles to their weakest positions, which weakens them, and stresses their attachments to bones. Together, this means that stretching both lowers the effectiveness of exercise and raises the likelihood of injury. Don't do it.

  • by John Hasler ( 414242 ) on Wednesday February 15, 2012 @10:35PM (#39055059) Homepage

    Well, 90% of one's max HR is simply that; to a certain point, it'll be higher the more fit you are.

    No it won't. In fact, as you get fit your max HR may decrease. However, you will be able sustain it much longer. Your heart will become stronger, will move more blood per stroke, and your circulatory resistance will decrease. Your resting HR (and your blood pressure) will drop substantially so that your ratio of max HR to resting HR will increase even if your max HR decreases.

  • Re:Interval Training (Score:5, Informative)

    by metlin ( 258108 ) on Wednesday February 15, 2012 @10:42PM (#39055107) Journal

    You know, I used to feel the same way (i.e. macros are more important, and as long as you got your nutrients, the source doesn't really matter).

    But a while ago, I changed my lifestyle -- vegetarian, gave up alcohol, coffee, and most processed foods, and just started eating healthier foods in general.

    I've seen a drastic difference in not just my fitness levels, but also my stamina. I'm having the flu right now, and yet, my buddies and I just had an intense workout out for over an hour at the gym, and I didn't even feel tired.

    Things like interval workouts are great, but they only work to an extent. There's something to be said about putting your body in the "zone" (as far as heart rates and muscle groups are concerned) because when you're done thoroughly working out with an entire muscle group, and you'll see much better progress over time. This, of course, is my personal experience and quite anecdotal. YMMV.

  • Re:Interval Training (Score:5, Informative)

    by metlin ( 258108 ) on Wednesday February 15, 2012 @10:53PM (#39055201) Journal

    for most people, even modest exercise is enough to keep them from getting fat and weak

    I would actually say that diet is infinitely more important than exercise. There's a reason it's said that six packs are made in the kitchen.

    Someone who eats healthy and does not work out is often in better shape than someone who eats junk and "works out" for half hour a day. Most of those people just use their momentum to do some crazy exercises with piss poor forms, and eat unhealthy crap afterwards because they've worked out (think middle aged man with flabby biceps and a beer gut trying to bench press, when he probably has 30% body fat).

  • Russian Kettlebells (Score:4, Informative)

    by JerkBoB ( 7130 ) on Thursday February 16, 2012 @12:04AM (#39055747)

    Not a whole lot more to say on the subject. Do some swings and get-ups once or twice a day, and you'll be fit and trim. Unless you eat trash and guzzle carbonated sugar water all day. In which case, you're fucked no matter what you do.

  • by korean.ian ( 1264578 ) on Thursday February 16, 2012 @12:08AM (#39055779)

    The more fit you are, the harder it becomes to approach your max heart rate. Your max doesn't get higher.

  • Re:Interval Training (Score:5, Informative)

    by littlewink ( 996298 ) on Thursday February 16, 2012 @12:18AM (#39055859)

    ... doing stretches weren't that good for the body and might do more injuries in the long run

    Yes, and doing yoga can f*** you up. [] So a little warming up and then straight into exercise or weights is best.

  • by RubberChainsaw ( 669667 ) on Thursday February 16, 2012 @12:39AM (#39056037)
    Slow burn is where to raise and lower a weight very slowly (about one rep every 20-30 seconds), while maintaining proper form. The idea is that you can't unconsciously use momentum and leverage to help you lift the weight, hence you will reach full fatigue faster than the standard quick rep method. Since you'll theoretically get a full workout in about 2/3rds the time, you spend less time in the workout overall.
  • Re:Interval Training (Score:5, Informative)

    by cmarkn ( 31706 ) on Thursday February 16, 2012 @01:18AM (#39056255)

    [citation needed] []

    “The basic science and clinical evidence today suggests that stretching before exercise is more likely to cause injury than to prevent it.”,7120,s6-241-287--7001-0,00.html []

    Several authors have suggested that stretching has a beneficial effect on injury prevention. In contrast, clinical evidence suggesting that stretching before exercise does not prevent injuries has also been reported. []

    “stretching before exercise is more likely to cause injury than to prevent it.” [] p. 218-9, emphasis in original

  • Re:Interval Training (Score:3, Informative)

    by cerberusti ( 239266 ) on Thursday February 16, 2012 @01:29AM (#39056309)

    I passed a jogger the other day while walking (I walk anywhere I can, in all weather, and was carrying 50 lbs of groceries at the time.)

    In any sort of traffic condition I tend to beat cars rather badly on distance over time (yes, I live in the city.) If you walk with the purpose of covering distance quickly under load, you can get pretty substantial exercise. If you walk daily and do so at speed this is all the exercise you really need to be healthy (assuming a reasonable diet.)

    I do try to ensure that I can run (not jog) 5 miles or so without too much issue a couple of times a year. If it is too hard, I invest the effort to correct this.

    As it turns out, humans do not need all that much exercise to maintain health. You do need some, and your diet must balance calorie intake with expenditure, but it is not hard at all to maintain physical health. If you are reasonably healthy to begin with, maintaining that is very easy.

    I do watch my diet to some extent, and make my own bread daily (I have a loaf baking before my coffee finishes brewing, bread machines kick ass.)

To be is to program.