intresting article i found
Hi guys as some might know i am studying physio and exercise physiology and work as a personal trainer for a few years now. and for uni i wrote this paper for an optional essay, (yes i am a nerd) hehe. This is my opionion on cardio and would like to here wat u guys think. its all facts.
This will casue some heated discussion but hey we are here to learn.
Working as a pt for the past years it has lead me certain conclusions about the standard cardio that many of my fellow personal trainers prescribe, I now tell clients that cardio does not burn fat and walking is not exercise. This horrifies many people from whom the most common retort is that ‘walking is better than nothing’. For those readers delighted by any achievement greater than ‘nothing’, keep walking! Half an hour, 3 times per week is all the exercise YOU will ever need.
But whilst ‘walking’ might very well be better than ‘nothing’ for the majority of the clinically obese civilian population, readers of this site HOPEFULLY reference their physical condition against higher benchmarks than ‘nothing’, ‘zero’ or ‘dead’.
How to manipulate fat
Manipulating body composition is based on 3 very simple principles:
• Food determines your weight
• Strength determines your lean mass
• Fat is the difference in between.
These principles are fact. They cannot be argued. And they provide clear direction for complete control of your body composition.
• If you want to alter your bodyweight, adjust your food intake.
• If you want to alter your lean mass, exercise to manipulate your strength.
• If you want to alter your FAT MASS, adjust your weight AND lean mass accordingly – generally, try to increase or maintain your lean mass (strength) while losing weight (eat less).
Where does cardio fit this equation? Basically, it doesn’t!
What Cardio Does
Cardio doesn’t make you eat less – you’ll probably be hungrier and eat more. If you are training with weights, cardio won’t make you stronger – you’ll probably be weaker. If you are eating more and losing strength then you are getting fatter. That is just math.
How Cardio Fails to Burn Fat
Exercise burns glucose. Even the ‘experts’ recommend that we consume carbohydrates (glucose) to fuel exercise; the same exercise that they contradictorily prescribe to burn fat.
To be more specific, the additional energy required to perform exercise is mainly provided by glucose. During low intensity exercise like walking, the body burns a high percentage of fat but only because few carbohydrate calories are required. This is where the whole ‘fat burning heart rate’ nonsense comes from. It is technically correct but totally irrelevant to achieving fat loss. Ironically, resting burns the highest percentage of fat simply because carbohydrate requirements are minimal.
The amount of fat being burned is virtually the same irrespective of exercise intensity, even though total energy and glucose requirements are greater.
Where Is The Fat?
'Cardio' doesnt 'burn fat'. If it did, then why is your bodyfat measurement IDENTICAL to what it was before you did your 'fat burning'? Why isnt the fat burned? That might sound stupid and simplistic but it is still valid. Point being that zero x 45mins x twice daily x 7 days per week is still ZERO.
'Cardio' doesnt raise metabolism for an extended period afterwards either. Not other than the repair response to muscular damage induced... you know, like you would've achieved better and more efficiently from one set of barbell squats!? The only studies showing a measured raise in metabolic rate were in endurance athletes and sedentary people. People who's muscles are traumatised by running/walking/riding. NOT heavy squatters!
When cardio does cause muscle trauma in weight trainers, the result is compromised recovery and muscle growth. And remember if you lose muscle you are relatively fatter than if you had kept that muscle.
Improved Capillary Density
Cardio does not help increase capillary density in weight trainers as the ‘experts’ hypothesise. Doing 5 sets of 20 reps on heavy bench presses is obvious stimulus to increase blood and nutrient supply to the pecs. The pounding heart and blood engorged, skin splitting 'pump' will attest to that. Peddling on an exercise bike, BY COMPARISON, is doing NOTHING for your pecs or any other weight trained muscle.
Cardio, despite the name, has negligible cardiovascular benefit to weight trainers that regularly train with high intensity. It would be ridiculous to think that a 30-45 minute walk would require cardiovascular fitness beyond that necessary to complete a 60-90 minute high-volume, high-intensity leg workout.
Any physiological alterations our bodies make are as an ADAPTIVE response to STRESS. Deadlifting 200+kg for reps is stressful. And a multi-set weights workout will leave your heart pounding at above 60% maximum heart rate for the entire workout. So we know it makes our cardiovascular system work.
20-40mins on the bike/treadmill shouldn’t stress any weight trainer too greatly... other than boring and irritating the hell out of them! The heart rate will be lower, less demands made of energy systems and the experience altogether easier - less stressful - than a high-intensity weights workout. As such, there is no positive adaptive response. The only possible adaptive response to endurance exercise is reduced muscle mass if the exercise is stepped up to a frequency, duration and intensity that IS stressful. This is the cardio paradox: if you do it effectively, you are worse off. If you do it ineffectively, by definition you wasted your time!
All of your internal organs exist only to support your muscles and your muscles have only one function: to exert force on your skeleton. If your muscles are required to regularly exert high levels of force on your skeleton – like when you lift weights – your whole body needs to function optimally. Nutrients need to be absorbed efficiently from the intestines, be processed efficiently by the liver, and then transported efficiently to the muscles where they can be used efficiently for repair and energy. The vascular system which is driven by the heart needs to then efficiently deliver waste products to be processed efficiently by the kidneys and bowels etc etc. At the end of the day, a healthy body is all about optimally performing muscles. Exercise is how we work the muscles and the most efficient form of exercise is WEIGHTS!
Cardio’s negative effect on body composition is 2-fold. Firstly, it stimulates the appetite making it more difficult to maintain a reduced calorie diet. Secondly, cardio burns the muscle glycogen that should be fuelling heavy weight workouts leaving you weaker and less muscular.
If you are lucky, your cardio won’t negatively affect your diet or your strength in which case you only wasted your time. At worst, cardio will cause you to fail your diet and your strength to fall leaving you at the same bodyweight but with less muscle. In other words, fatter. And yes, it does happen. Regularly.
Your bodyweight is your fat mass plus your lean mass. As such, if your goal is to reduce your bodyfat percentage then your goal is also to increase your lean mass percentage. For some reason, weight trainers recognise the negative effect of cardio on lean mass but erroneously believe that it will positively affect their lean mass percentage. This is obviously a mathematical impossibility.
But You’ve Seen it Work?
So what about those people you know that started walking and lost weight? Well for completely inactive lumps of lard (like most of the population), simply squatting the weight of their own fat arse to get up off the sofa forces their body to build some muscle. Carrying their collection of fat rolls down the street will require even more muscle (and will hopefully stop them eating for half an hour). So they lose weight by eating less and gain muscle by lifting their own fat. They are leaner, but it wasn’t because the walking ‘burned fat’.
Running will result in superior fat loss to walking because relatively more STRENGTH is required to accelerate your bodyweight. Sprint Interval training will result in superior fat loss to running for the same reason: you need more strength. What do you think requires and builds the most strength? That’s right; WEIGHTS!
Unfortunately, when a decreasing bodyweight is providing the stimulus for strength gain, it is only a short time before improvements cease. This is why the cardio approach to fat loss ‘stalls’. The only way to achieve a high lean mass percentage is to engage in much higher intensity exercise such as weights. Unless you want to starve yourself down to the weight of your skeleton.
Energy In/Energy Out?
How about the calorie in/calorie out equation that all of the scientists talk about? For the most part it is entirely true… when you are talking about WEIGHT loss. But weight loss is an entirely different issue to altering your body composition for relatively less fat. It is possible to lose weight and wind up with relatively more fat – that’s what happens when you do a ‘soup diet’ or some equally stupid starvation plan: your weight loss is mainly muscle (and water) so you become lighter but relatively fatter.
While exercise does burn energy, the quoted figures are usually misleading. For instance, most authorities say that walking will burn 200-400 calories per hour. What is seemingly forgotten is that your body would have burned around 100-200 calories just to stay alive anyway. Remember, physical activity is not the only thing your body needs energy for. There are the basic ‘house keeping’ things like keeping your body and brain alive – though your brain does pretty much stop and die while you do cardio.
Anyway, only about 100-200 ADDITIONAL calories are actually burned by an hours walking – equivalent to 1 Tim Tam. You’d have to be mentally retarded to want to pay for each Tim Tam you eat with an hour of your life?
Another problem with the energy in/energy out equation is that we really have no idea what the ‘energy out’ part is or where that energy is drawn from. For instance, if liver glycogen provides the additional 150 calories required by a one hour walk, potentiation of active T3 thyroid hormone may be slightly suppressed resulting in a slightly lower metabolic rate. A reduction in resting metabolism of just 10 calories per hour is a net 90 calorie DECREASE in the days energy expenditure (24 x 10 -150 = 90).
Irrespective of whether cardio could burn fat or not, you would have to question how much of a difference it can make to a weight trainer anyway. As an extreme example, take a 100kg competitive bodybuilder with 8% bodyfat and a dietary intake of 5000 calories.
Unfortunately, what this bodybuilder will usually do is immediately reduce calories to less than 2000 per day while adding up to 3 hours of cardio. In 10 weeks he will compete at 3% bodyfat but in the under 70kg class because he starved and ran off all of his muscle.
To achieve 3% bodyfat, our bodybuilder above only needed to lose 5kg of fat weight. Over 10 weeks this amounts to a very realistic and manageable 0.5kg per week. Coming off a 5000 calorie base means that removing 200-300 calories per week is quite manageable and will maximise fat loss and muscle retention. The thermogenic, anabolic and anti-catabolic supplements he will undoubtedly take will further accelerate fat loss and help maintain muscle. There is absolutely no possible benefit that could be realised by adding cardio even if it did ‘burn fat’.
So if cardio doesn’t burn fat, what does? The answer is that it doesn’t even matter how or when the body burns fat. Fat is just the difference between how much you weigh and how much muscle you have. Consider again the equation above:
• Food determines your weight
• Strength determines your lean mass
• Fat is the difference in between
If you want to be leaner, you need to improve your muscle to bodyweight ratio. You can reduce your bodyweight while maintaining muscle or gain muscle while maintaining bodyweight. Either way, the only tools necessary to do this are diet and heavy weights. How you diet and train is a whole other story. But regardless of whether you are male or female, tall, short, big or small, if you want to achieve low bodyfat, ditch the cardio and get back to the heavy weights!
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