Aerobic vs anaerobic training – what’s the difference?

As the festive season is well and truly upon us, it goes without saying that most of us, even with the best of intentions, will end up over-indulging on food and drink. So in anticipation of the new years’ “rush” I thought I’d finish the year with a fitness training article. Here’s the lowdown on the body’s aerobic and anaerobic energy systems – what they are, how they work and which is best way to workout for you. Merry Christmas everyone!

Aerobic and anaerobic are simply terms used to describe how the cells within the body produce energy and refer to energy systems. Every movement we make requires energy to be created and there are three main ways that this is done: one with oxygen – aerobic, and two without oxygen – anaerobic.

Aerobic

Aerobic refers to the body producing energy with the use of oxygen. Continuous steady state exercise is performed aerobically. When it comes to aerobic exercise, you would usually think of spending anywhere from 20-90 minutes performing an exercise – this could be on an exercise bike, treadmill or cross trainer or even simply walking and jogging.

The aerobic energy system utilises fats, carbohydrates and sometimes proteins to produce adenosine triphosphate (known as ATP – see my earlier blog post on EPOC here) for energy use. It produces far more ATP than either of the anaerobic energy systems but at a much slower rate, therefore it cannot fuel intense exercise (such as HIIT) that demands the fast production of ATP.

Aerobic exercise – walking/jogging

Anaerobic

Anaerobic refers to the body producing energy without oxygen. This is typically exercise that is performed at a higher intensity. There are two ways that the body can produce energy anaerobically:

  • The ATP-PC system, which consists of adenosine triphosphate (ATP) and phosphocreatine (PC). This provides immediate energy through the breakdown of these stored high energy phosphates.  If this energy system is ‘fully stocked’ it will provide energy for maximal intensity short duration exercise for around 10-15 seconds. It provides you with the most power because it produces ATP more quickly than any other system. Because of this it fuels all very high intensity activities but it burns out very quickly. (See also my earlier blog post on EPOC here).
  • The Anaerobic Glycolytic system produces a lot of power, but not quite as much or as quickly as the ATP-PC system.  However it has larger fuel supplies (essentially a bigger fuel tank) and doesn’t burn all its fuel as quickly as the ATP-PC system, nor does it fatigue as quickly. It is the anaerobic glycolytic system that is associated with the feeling of burning in your muscles due to the build-up of lactate and other metabolites.
Anaerobic exercise – high intensity box jumps

Which is the best?

During exercise, energy will be derived from all three of these systems, but the emphasis will change depending on the intensity of the exercise relative to your fitness levels.

Aerobic vs anaerobic training refers to which energy system you are trying to improve during your training session - its structure and intensity will be very different depending on which one you are trying to improve.

Aerobic training will typically fall in the range of 60 – 80% of your estimated maximum heart rate and can be performed continuously for prolonged periods of time. Anaerobic training will fall between 80 – 90% of your estimated maximum heart rate.

  • Aerobic training is good for building endurance and improving your cardiovascular and respiratory function. This means that your heart and lungs become stronger and more efficient, enabling you to train harder and longer as your fitness levels improve.
  • Anaerobic training is performed at a harder intensity than aerobic exercise, typically between 80 – 90% of your maximum heart rate. 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. It is a great way of really improving your fitness levels once a baseline aerobic level of fitness is achieved.

Have a wonderful Christmas, try not to eat too much, and look forward to a fit and healthy you in the new year!

Are you REALLY doing HIIT?

Love love love this article from Metafit Australia and simply had to share! There are many people who seem to think that back to back so-called High Intensity workouts are the best way to up their fitness and strength, but that’s simply not the case. Discover why the short sharp intense Metafit workout is one of the best ways to deliver a true HIIT workout …

Most people who claim they do high-intensity interval training often focus more on the ‘interval’ part than on the ‘high intensity’ part. Let’s get one thing straight – there’s nothing wrong with regular interval training. You do the exercise for a period of time, then rest and repeat the exercise again, thus forming intervals that are great for your heart health, circulation, and overall conditioning. But doing exercises with high intensity is where the magic happens.

Most people are drawn to HIIT because it’s short and it’s a type of cardio that doesn’t require any equipment at all to have a good total body workout. The question is, how do you know you’re doing HIIT right? Well doing HIIT on your own is very difficult and most people will never achieve the right intensity so a much more effective way is it under the guidance of a qualified Metafit coach or personal trainer.

What qualifies as high intensity?

After each interval, you should be out of breath, drenched, and thinking to yourself “Thank God it’s rest time, I couldn’t go on any longer”. Your body will treat that rest time as a quick recovery, giving you the chance to steady your breath and gather just enough energy to perform the next interval. To illustrate how hard you have to work in those short intervals (that usually last anywhere from 15 to 45 seconds), it’s worth noting that some researchers doubt that the general population could successfully adapt to the extreme nature of HIIT. However, in Metafit we challenge that belief. The general population can absolutely achieve the right intensity (90% + MHR) with expert coaching, correct programming (exercises, work to rest, duration) and determination.

Don’t underestimate the rest periods

This is such an important thing to note because people usually think that if they push themselves harder and harder with no breaks whatsoever, they will somehow achieve better results. Wrong! The rest periods are what makes HIIT work! In order to really perform at your maximum intensity, you have to give your body a chance to recover! If you just go on doing something so extreme for long, your body will slowly decrease the energy levels, which can lead to serious injuries and won’t help your fitness goals in the long run. The whole point of the rest period is to allow your body to tap into the energy supplies it has, and ‘produce’ the amount of energy you need for your next interval. Without that break, you’re not giving your body a chance to regroup and prepare itself for the hard part. Remember, it’s called high-intensity interval training, and not just high-intensity training for a reason. By going through those high cardio – low cardio intervals, you’re making the most out of your workout, whether the goal is to lose fat, increase explosiveness, or simply improve your general health.

Longer is not necessarily better

Now that we’ve established that your workout should be rough and leave you breathless and sweaty, there’s another aspect of this exercise regimen you should take into account when planning your workout – it’s length. If you’re really making your body go through intense energy bursts where you’re giving it your all, it’s impossible to perform those intervals for longer periods of time. There isn’t a professional athlete in the world that could or would want to do HIIT for an hour. You’ll come across various 45, 60, or even 80-minute ‘HIIT’ workouts on the internet that deserve a healthy amount of suspicion, to say the least.

The ideal length you should go for is anywhere between 6 and 25 minutes, no more. If you do it right, you’ll give your body an excellent, fat-torching routine that will leave you feeling energised and oh so alive! The easiest way to choose the optimal length is to simply listen to your body and find what feels good for you.

Which exercises to choose

It’s not only the way you do it but what you do that counts. You should aim for bodyweight, explosive, full body moves that simultaneously engage most of the main muscle groups in your body to get an optimal result. Giving the limiting length of the intervals, it’s hard to imagine an average person being completely out of breath by the time they finish 20 seconds of squat pulses, triceps dips or crunches. Try doing burpees, squat jumps and sprints movements and you’ll see that you’ll pretty much max out at about 20 seconds or so.

You might think that your typical HIIT workout focuses too much on the lower body, but don’t be fooled; one, quads and glutes are the largest muscles in the body, therefore they will burn the most calories when being trained, and two, in order to do a high-intensity burpee or jumping lunge the right way, you need to activate your core to keep you balanced and safe. Don’t worry, you’ll be doing a total body routine, without even noticing it or focusing on specific abs or arm exercises. That’s the beauty of HIIT.

Less is MORE

Falling in love with HIIT is easy. It’s quick, effective, and the results start to show fast – really, really fast. You might love it so much, in fact, that you’ll find yourself trying to fit the fourth or even fifth HIIT in your week, in order to achieve even faster results. Don’t do it! Aim for 2 or 3 HIIT workouts per week, max. Even just one quality HIIT workout per week will do wonders for your athletic performance. Your body needs time to recover properly; you should cherish it and work with it, not against it. Feel free to do some weight lifting, yoga, pilates or light, steady-paced cardio on your off-days. This will compliment your HIIT routine perfectly, and keep you safe from injuries and stress. If you overwork your body, it will likely recover slower than usual, causing you to have less energy to begin with, so you won’t be able to make your intervals intense and brutal, which will render your whole HIIT routine useless, not to mention the probable muscle tears and Achilles tendinitis that often go along with lower performance.

In the end, HIIT will make you appreciate what your body can do as well as boost your overall health and wellbeing, as long as you do it right. Ready, set, HIIT! 

Thanks to Metafit Australia.

Metafit is an absolute gem of a workout and is one of my all-time favourites. It's simply one of the quickest ways to visibly improve your fitness and strength. I am fully certified to teach both the standard Metafit workout and also the circuits based MetaPWR workout.

EPOC – Metafit’s jewel in the crown

Burn fat in your sleep with Metafit! The 30-minute class that lasts 24 hours! The HIIT workout that keeps on working! These are just some of the claims that Metafit loves to make but what exactly do they mean and are they true?

I love Metafit. It’s by far my favourite workout. In under 30 minutes you can have an intense workout that burns fat, boosts metabolism and improves strength, speed and cardiovascular fitness. It is one of the quickest ways to improve your overall fitness and for beginners, if you’re committed and work hard three times a week, you can easily start to see real results within 6-8 weeks. So what is it about this short workout that makes it so successful?

The answer is simple: EPOC.

Excess Post-exercise Oxygen Consumption (also referred to as the “afterburn” effect) is an increased rate of oxygen intake following strenuous activity. Essentially, our body uses more oxygen after exercise than before exercise, and we expend more calories during our recovery from exercise than we do before exercise, even at rest. EPOC is the amount of oxygen required to restore your body to its normal resting metabolic function called homeostasis.

Your metabolism is how your body converts the nutrients you consume in your diet to adenosine triphosphate (or ATP), the fuel your body uses for muscular activity.

Here are seven important points about EPOC and how it can help you achieve optimal levels of calorie burning from your workouts:

1. During the immediate post-exercise recovery period, oxygen is used for the following functions:

  • Production of adenosine triphosphate (ATP) to replace the ATP used during the workout,
  • Re-synthesis of muscle glycogen from lactate,
  • Restore oxygen levels in venous blood, skeletal muscle blood and myoglobin,
  • Work with protein for the repair of muscle tissue damaged tissue during the workout,
  • Restore body temperature to resting levels.

2. Exercise that consumes more oxygen burns more calories.

The body expends approximately five calories of energy to consume one litre of oxygen. (A calorie is the amount of energy required to heat one litre of water to 1°C). Therefore, increasing the amount of oxygen consumed both during and after a workout, can increase the amount of net calories burned.

3. Circuit training and heavy resistance training with short rest intervals = a significant EPOC effect.

Strength training with compound, multi-joint weightlifting exercises or a weightlifting circuit that alternates between upper and lower-body movements places a greater demand on the involved muscles for ATP from the anaerobic pathways. Increased need for anaerobic ATP also creates a greater demand on the aerobic system to replenish that ATP during the rest intervals and the post-exercise recovery process. Heavy training loads or shorter recovery intervals increase the demand on the anaerobic energy pathways during exercise, which yields a greater EPOC effect during the post-exercise recovery period.

4. High-intensity interval training (HIIT) is the most effective way to stimulate the EPOC effect.

The body is most efficient at producing ATP through aerobic metabolism, however at higher intensities when energy is needed immediately, the anaerobic pathways can provide the necessary ATP much more quickly. This is why we can only sustain high-intensity activity for a brief period of time – we simply run out of energy. HIIT works because during high-intensity exercise, ATP is produced by the anaerobic pathways – once that ATP is exhausted, it is necessary to allow it to be replenished. The rest interval or active-recovery period during an anaerobic workout allows aerobic metabolism to produce and replace ATP in the involved muscles. The oxygen deficit is the difference between the volume of oxygen consumed during exercise and the amount that would be consumed if energy demands were met through only the aerobic energy pathway.

5. EPOC is influenced by the intensity, NOT the duration of exercise.

Higher intensities require ATP from anaerobic pathways. If the ATP required to exercise at a particular intensity was not obtained aerobically, it must come from the anaerobic pathways. During EPOC, the body uses oxygen to restore muscle glycogen and rebuild muscle proteins damaged during exercise. Even after a HIIT workout is over, the body will continue to use the aerobic energy pathway to replace the ATP consumed during the workout, thus enhancing the EPOC effect.

6. Research has shown that resistance training can provide a greater EPOC effect than running at a steady speed.

One study found that when aerobic cycling, circuit weight training and heavy resistance exercise were compared, heavy resistance exercise produced the biggest EPOC.

7. The EPOC effect from a HIIT or high-intensity strength-training workout can add 6-15% of the total energy cost of the exercise session.

High-intensity workouts require more energy from the anaerobic pathways and can generate a greater EPOC effect, leading to extended post-exercise energy expenditure. Heavy weight training and HIIT workouts appear to be superior to steady-state running or lower-intensity circuit training in creating EPOC.

Watch Metafit’s Justin Corcoran (below) demonstrate the correct technique for the exercises in the May 2018 “10 Lashes” workout:

Increasing the intensity of your workouts will produce results.

It is important to remember that it is the intensity of your workout that produces the results. There is some debate about the significance of the EPOC effect for the average exercise participant because the high-intensity exercise required for EPOC can be extremely challenging. However, if you want results and are up for the challenge, increasing the intensity of your workouts by using heavier weights, shorter rest intervals or high-intensity cardio intervals may be worth the effort. While HIIT or heavy resistance training is effective and beneficial, remember to allow at least 48 hours of recovery time between high-intensity exercise sessions and try to limit yourself to no more than three strenuous workouts per week.

Thanks to the American Council on Exercise.

Metafit tips:

  • At the end of every Metafit session you should feel exhausted and be unable to hold a conversation for a minute or two.
  • If you are able to carry out a conversation during your workout you are not pushing yourself hard enough and you are unlikely to reach EPOC.
  • It’s important to get your technique right and it is better to use the regressive form of each exercise if you are struggling to maintain technique. Poor technique = less benefit and more likelihood of injury.
  • Think “slow and controlled” for your core exercises, particularly hot hands and hot knees.
  • That voice that says “I can’t do it” is the very same voice that says “I can do it!” Your mind will tell you “I can’t continue!” but if you push yourself a little further each time you will see that your body is perfectly capable of doing additional reps. Keep going no matter what – remember each interval is usually no more than 25 seconds.
  • If you are finding an exercise easy, then progress your technique by adding a jump or a tuck jump (for instance, adding a tuck jump after a burpee). Please ask me and I can show you progressions on all your exercises.
  • Metafit should never get easier – the fitter you become, the harder you can push yourself.

BBC – The Truth About Getting Fit

By the middle of January many people struggle to keep up their resolutions to be more active. The result is that the UK wastes nearly £600 million a year on unused gym memberships.

But new science has the answers.

Medical journalist Michael Mosley teams up with scientists whose latest research is turning common knowledge about fitness on its head.

They reveal why 10,000 steps is just a marketing ploy and that two minutes of exercise is all a person needs each week. They discover how to get people to stick to their fitness plans and what exercise can actually make everyone more intelligent. Whether it is for couch potatoes who hate the thought of exercise, someone too busy to consider the gym, or even for fitness fanatics who are desperate to do more – science can help everyone exercise better.

A great programme and some fascinating insights! Do watch it if you get the chance.