Anaerobic exercise - Wikipedia
(Redirected from Anaerobic threshold)
Anaerobic exercise is exercise intense enough to trigger anaerobic metabolism. It is used by athletes in non-endurance sports to promote strength, speed and power and by body builders to build muscle mass. Muscle energy systems trained using anaerobic exercise develop differently compared to aerobic exercise, leading to greater performance in short duration, high intensity activities, which last from mere seconds up to about 2 minutes.[1][2] Any activity lasting longer than about two minutes has a large aerobic metabolic component.[citation needed]
In contrast, aerobic exercise includes lower intensity activities performed for longer periods of time. Activities such as walking, running (including the training known as an interval workout), swimming, and cycling require a great deal of oxygen to generate the energy needed for prolonged exercise (i.e., aerobic energy expenditure). In sports which require repeated short bursts of exercise however, the anaerobic system enables muscles to recover for the next burst. Therefore training for many sports demands that both energy producing systems be developed.
There are two types of anaerobic energy systems: 1) the high energy phosphates, ATP adenosine triphosphate and CP creatine phosphate and, 2) anaerobic glycolysis. The high energy phosphates are stored in very limited quantities within muscle cells. Anaerobic glycolysis exclusively uses glucose (and glycogen) as a fuel in the absence of oxygen or more specifically, when ATP is needed at rates that exceed those provided by aerobic metabolism; the consequence of rapid glucose breakdown is the formation of lactic acid (more appropriately, lactate at biological pH levels). Physical activities that last up to about thirty seconds rely primarily on the former, ATP-PC phosphagen, system. Beyond this time both aerobic and anaerobic glycolytic metabolic systems begin to predominate. The by-product of anaerobic glycolysis, lactate, has traditionally thought to be detrimental to muscle function. However, this appears likely only when lactate levels are very high. Elevated lactate levels are only one of many changes that occur within and around muscle cells during intense exercise that can lead to fatigue. Fatigue, that is muscular failure, is a complex subject. Elevated muscle and blood lactate concentrations are a natural consequence of any physical exertion. The effectiveness of anaerobic activity can be improved through training.[1] [6]
Anaerobic metabolism
Anaerobic metabolism, or anaerobic energy expenditure, is a natural part of whole-body metabolic energy expenditure.[3] Fast twitch muscle (as compared to slow twitch muscle) operates using anaerobic metabolic systems, such that any recruitment of fast twitch muscle fibers leads to increased anaerobic energy expenditure. Intense exercise lasting upwards of about four minutes (e.g., a mile race) may still have a considerable anaerobic energy expenditure component. Anaerobic energy expenditure is difficult to accurately quantify, although several reasonable methods to estimate the anaerobic component to exercise are available.[2][4] [5]In contrast, aerobic exercise includes lower intensity activities performed for longer periods of time. Activities such as walking, running (including the training known as an interval workout), swimming, and cycling require a great deal of oxygen to generate the energy needed for prolonged exercise (i.e., aerobic energy expenditure). In sports which require repeated short bursts of exercise however, the anaerobic system enables muscles to recover for the next burst. Therefore training for many sports demands that both energy producing systems be developed.
There are two types of anaerobic energy systems: 1) the high energy phosphates, ATP adenosine triphosphate and CP creatine phosphate and, 2) anaerobic glycolysis. The high energy phosphates are stored in very limited quantities within muscle cells. Anaerobic glycolysis exclusively uses glucose (and glycogen) as a fuel in the absence of oxygen or more specifically, when ATP is needed at rates that exceed those provided by aerobic metabolism; the consequence of rapid glucose breakdown is the formation of lactic acid (more appropriately, lactate at biological pH levels). Physical activities that last up to about thirty seconds rely primarily on the former, ATP-PC phosphagen, system. Beyond this time both aerobic and anaerobic glycolytic metabolic systems begin to predominate. The by-product of anaerobic glycolysis, lactate, has traditionally thought to be detrimental to muscle function. However, this appears likely only when lactate levels are very high. Elevated lactate levels are only one of many changes that occur within and around muscle cells during intense exercise that can lead to fatigue. Fatigue, that is muscular failure, is a complex subject. Elevated muscle and blood lactate concentrations are a natural consequence of any physical exertion. The effectiveness of anaerobic activity can be improved through training.[1] [6]
References
- ^ a b Anaerobic training
- ^ a b Medbo, JI; Mohn, Tabata, Bahr, Vaage, Sejersted (January 1988). "Anaerobic capacity determined by maximal accumulated O2 deficit". Journal of Applied Physiology 64 (1): 50–60. Retrieved 14 May 2011.
- ^ Scott, Christopher B (June 2005). "Contribution of anaerobic energy expenditure to whole body thermogenesis". Nutrition & Metabolism. 14 2. doi:10.1186/1743-7075-2-14. Retrieved 14 May 2011.
- ^ Di Prompero, PE; G. Ferretti (Dec. 1). "The energetics of anaerobic muscle metabolism". Respiration Physiology 118 (2-3): 103–115.
- ^ Scott, Christopher B (2008). A Primer for the Exercise and Nutrition Sciences: Thermodynamics, Bioenergetics, Metabolism. Humana Press. pp. 166. ISBN 978-1-60327-382-4.
- ^ McMahon, Thomas A (1984). Muscles, Reflexes, and Locomotion. Princeton University Press. pp. 37–51. ISBN 0-691-02376-X.
See also
- Lactate threshold
- Aerobic exercise
- Wingate test (a test of anaerobic capacity)
Well, now that’s an interesting question. Endorphins are one of the circadian immune molecules we want to promote by exercising. Their presence reflects improved health, and cause it.
It definitely feels better when we become healthier through exercise, and so many people learn from experience that it’s a good idea to exercise, and come to want to do it.
But for most sedentary people, there’s no desire in advance of exercise to go do it; and there’s no great pleasure in the first day of exercise. As I understand it, it’s prospective wanting (motivating action) and concurrent liking (rewarding it) that the innate reward system of the brain generates. And those cues seem to be lacking.
Best, Paul
I used to go through 3-5 months bouts of over-exercising in my attempt to manage my weight. The only other time (before Paleo/PHD) that I successfully lost a substantial amount of weight was a few years ago at which time I severely restricted calories and exercised 1-2 hours most days of the week for a 2-3 month period. T’wasn’t healthy, t’was miserable, it ended quickly, and I gained all the weight back and more.
Last fall before learning about Paleo/PHD/etc, I spent two months meticulously counting/limiting calories and doing long cardio sessions 5-6 days a week. After two months the scale hadn’t budged.
Since starting Paleo/PHD in January I have lost 60 lbs and put on a bunch of muscle with ease. I loosely follow Mark Sisson’s fitness rx – I lift heavy things (mostly myself) once or twice a week, I do a full on sprint every week or so, and I do plenty of enjoyable walking, biking, and playing as I am able.
I definitely prefer smart, manageable, and cheap exercise over what I used to think I needed
Perhaps we didn’t need innate rewards when exercise helped us get food, a mate, status, territory etc. Athletes and other performers still get those rewards.
Yes, that’s an important point. Intensity is a totally different variable than volume and its health effects have to be studied independently.
Yes, there does seem to be a lot of evidence in favor of HIIT. However, the ability to increase intensity is correlated with health, so we have to be careful in analyzing studies.
A personal experience:
The last couple of months I have been doning crossfit style exercise. Lately I have been pondering if I was generally feeling a litle bit better when I was doing more leangains style training.
What I still really like about crossfit is the community and the focus on learning new movements and improving mobility and not only focusing on gaining muscle.
Can’t wait for the new book!
Exercise: a very complex subject indeed. Based on a recent study, maybe we should not encourage sick people to exercise (at least not more than brisk walks) but try to get healthy first. I think Table 1 is visually very revealing (and disturbing):
Adverse Metabolic Response to Regular Exercise: Is It a Rare or Common Occurrence?
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3364277/
Yes, I think exercise intensity and volume need to be scaled with health. Exercise should be refreshing, not stressful. For unhealthy people that means a brisk walk may be the most they should do.