A LONG time ago, aerobic exercise or slow boring cardio was considered to be better for burning unwanted fat. This theory makes sense in a way as fat is the preferred fuel for such low intensity activities such as slow jogs, aerobic classes and sleeping etc. The body burns fat when free fatty acids are used for fuel in conjunction with oxygen (i.e fat burning zone)

Hang on one minute. Answer this; how many hours are there in a day? 24, right, so why when training to lose fat, do most people only focus on burning calories for 1 hour or so, doesnt it make sense to maximise the fat burning effect throughout the whole day? Of course it does. But most people I speak to think it doesn’t make sense to only train for half an hour and instead, will just plod along watching the calories burned on a x-trainer/treadmill/bike for an hour or so.

Maybe going to the gym, class, jogging is a social thing for most people, but for me personally, I want to get done what I have to do in the quickest time possible and get home and enjoy being with my young family and run my business. Don’t get me wrong, I’m not dismissing aerobic exercise altogether, but if we’re armed with the knowledge of both protocols (Aerobic vs Anaerobic), it only makes sense to train with the most effective.

Research has shown that its more important to focus on the events that place after a workout, as intense exercise sessions lead to significantly higher post exercise energy expenditure, resting metabolic rate will be increased, which will ultimately, turn your body into a fat burning machine 24/7!!!

Science has confirmed this many times (bear with me one minute) so instead of focusing solely on the energy or calories burned during the workout, it's far more important for fat loss to consider overall calories expended throughout the day.


Research:

The most famous study was conducted by Tremblay and colleagues in 1994, where they compared the effects of endurance training and high intensity intermittent training. Two separate groups were evaluated. The endurance group followed a program for 20 weeks and the interval group followed a program for 15 weeks. The results found that the interval group lost a heck of a lot more body fat despite the fact that the endurance group burnt more calories in the actual workout and had a 5 week advantage!


Equally as famous: The Tabata protocol

This method of conditioning was made famous by Dr. Izumi Tabata and his team at the National Institute of Fitness and Sports in Tokyo. The team was looking at different exercise protocols and their effect on the energy production systems of athletes with the aim of finding ways to increase both anaerobic and aerobic conditioning. They tested a number of very intense protocols but found that the one called 1E1 tested both systems, this is the 20 seconds on and 10 seconds off method we see today.



Why use Tabata?

The Tabata method is incredibly good for conditioning and this is great for most athletes but what if you are not interested in the physiological conditioning but rather about conditioning and how it relates to body fat levels and muscularity?

Reduced body fat levels: Although Tabata has been used for energy system work it was quickly found that it is a hugely effective way to strip fat from the body. The training is itself brief, but the knock on effects are increased calorie utilization through the day and more importantly, an increased rate of fat burning in the hours after training. While low intensity long duration work has you burning fat on the cross-trainer/treadmill/bike for say 1 hour, Tabata causes you to increase the rate for fat burning for many hours after.



Resistance training vs aerobic exercise.

This study compared resistance training (weights) vs aerobic exercise (slow boring cardio). Both workouts were equal in duration and intensity with the results confirming that oxygen consumption (EPOC) was much higher following the resistance workout. And furthermore, elevated oxygen consumption continued for a longer time after the workout had ended. (Burleson, 1998) Slow boring cardio reduces power and strength (look at marathon running compared to sprinters) and don’t forget that more muscle burns more calories as energy is used to build and maintain muscle.


Theories:

Intense exercise increases the enzyme 3-hydroxyacyl CoA dehydrogenase who’s job it is to break down fats into energy.

Intense exercise can promote acetyl-CoA carboxylase (ACC) inactivation. Malonyl-CoA is synthesized by ACC and is an inhibitor of fatty acid oxidation. When you exercise, there’s a decline in malonyl-CoA and is accompanied by inactivation if ACC. As exercise intensity rises, theres an increased inactivation of ACC (Rasmussen, 1997)

Other research has found a link between fat expenditure following intense exercise and growth hormone release. Growth hormone is know to influence lipolysis, the breakdown of fat stored in fat cells. One study found that ‘the increase in fat expenditure during recovery was directly related to GH release’ (Pritzlaff et al, 2000)


I was wondering how many of you are still using aerobic exercise as your primary means of physical exercise for fat loss, and how many people have switched over to mainly Anaerobic, and how would you compare the two now looking back???

-Rob

i do mainly anerobic now and much prefer that to keeping lean, weights, boxing, and some explosive stuff on the bike, rower and treadmill. plus i play rugby so doing long bouts of cardio are useless for me and my sport. never found cardio to be effective for me, plus its boring as hell!

They both have their uses, and making claims that one is automatically "better" than the other is unwarranted, in my opinion.

Here's a couple of articles from Lyle McDonald on the subject. I am only linking the summary articles - although I recommend reading the other articles he has written on the subject:

Steady State vs. Interval Training: Summing Up Part 1 | BodyRecomposition - The Home of Lyle McDonald

Steady State vs. Interval Training: Summing Up Part 2 | BodyRecomposition - The Home of Lyle McDonald

Steady State vs. Interval Training: A Conclusion | BodyRecomposition - The Home of Lyle McDonald

Lyle is a great guy to read because he looks at the science behind various claims, and actually reads and deconstructs the research to see what is really going on.

Going through his steady-state vs interval articles, a few points stand out for me:
1. Research suggests that walking (low-intensity ss cardio) is the best exercise for permanent weight loss among obese people.
2. Most people (and in particular most very heavy people, the kind of people most likely to be using this forum) don't do intervals hard enough to get any real effect from them that they couldn't get, probably even better, from ss cardio.
3. The effect of EPOC seems to be greatly overestimated by interval supporters.

Ultimately, the most effective exercise routine is the one that you will actually do consistently. Most people can't or won't do HIIT hard enough to get the results that they interval gurus claim. And they are far more likely to hurt themselves trying, which only slows things down more.

I don't doubt that for really fit guys like you and Ben, that ss cardio is not as time-efficient as more intense workouts, but time-efficiency isn't the only important variable.

Take me as an example - I'll happily swim or walk/jog for an hour, but a HIIT session will burn me out fast, burn fewer calories (although in a shorter time), and possibly make me not want to go back to the gym/pool/track the next day. So which is better for fat loss?

I'm not saying that interval training is not good - far from it. It just isn't the right answer for all of the people all of the time.

Ditto Cord.

Some great points there Cord, I've never really thought of it that way... thanx.

Unconditioned = whatever you can consistantly keep up on a regular basis, anything has got to be be better than nothing?

Conditioned = HIIT?

again i suppose its all down to finding what works for you!!! id be the opposite cord, you love a good swim whereas id rather do 5 rounds in the ring or do some plyometrics etc. i havent read the articles but does lyle talk about muscle fibre composition and body types? these can have a big effect on what exercise works for people. good topic though

We can't speak about adaptations of our bioenergetic/cardiorespiratory/neuromuscular systems without clearly defining training goals.

If we're speaking about fat loss, we're splitting hairs worrying about this or that. If conditioning allows, a couple of high intensity sessions per week and a few low/moderate intensity sessions per week is probably the sweet spot in my experience.

If we're speaking about conditioning for performance, that's a whole 'nother ball game. In this context, the pendulum has swung too far to the side of high intensity interval training in my opinion. There are very important aerobic adaptations that are bypassed when we leave out low/moderate work that negates all levels of conditioning and performance.