Aerobic activity will kill you. Aerobic activity will give you a heart attack. Aerobic activity will deplete your sex hormone levels and age you. Aerobic activity will waste away your muscles. Don’t do aerobic activity!
Headlines such as these have been circulating like wildfire lately. I’m not sure exactly why there’s more now – perhaps it’s due to the huge increase in people who are entering and running half or full marathons; I’ll get to them in Part V of this series. Several CrossFit aficionados and various well known personal trainers are anti-aerobic and they feel that you have to kick your own ass day in, day out, to achieve results (strength, power, and a ripped body). I’ll give you my take based off personal experience, professional experience, research, and knowledge gained from those who know more than me about various subject matters.Whether you’re an endurance athlete, strength athlete, or a little bit of both I hope there’s something you will learn. Even though I come from a deep endurance background I’m not going to say aerobic training is the ideal way to train all the time, (because it isn’t). But aerobic exercise sure isn’t going to wreck your health and strength if done properly. Actually, it’s much the opposite. There’s a time for it all more or less.
What Exactly Do You Mean By Cardio?
To start off with, most people are using the word “cardio” to describe what they think is aerobic conditioning. A”cardio” activity can be either aerobic or anaerobic, depending on the level of effort and exertion required for that individual to do the exercise. Often people train “cardio” anaerobically – they are exercising at a high intensity. These people have neglected to develop a key component of their health and fitness – the aerobic system. Calling anything endurance “cardio” is just as wrong as calling everything you lift, carry, or throw “weight lifting.” It’s a generalized non-specific term. Just as cardio can mean walking 100 meters or running a marathon, weight lifting can mean carrying your laundry from your wash room to your bedroom or it could mean deadlifting three times your body weight. So let’s talk aerobic and anaerobic when it comes to “cardio.” If we don’t do so I might have nightmares of Richard Simmons in his running shorts. Nobody wants that.
Aerobic Capacity: Building a Solid Foundation
Your aerobic system provides a solid foundation for good health. It is the system that predominately moves you efficiently through the day as these muscles support your overall posture. Training your aerobic system will increase mitochondria in your muscle cells to generate energy (ATP) and increase capillary vascularization for increased oxygen utilization. These mitochondria burn fat and glucose (sugar), but they’re much more efficient using fat as energy over glucose – twelve times more. In general, Type I, red, slow twitch muscle fibers are aerobic and burn primarily fat for energy.
Aerobic conditioning is also a necessary foundation of virtually all training. Some exception could possibly be made for sprinting less than 200 meters (one time, no repeats), but most activities or sports will best be performed with a well developed aerobic system. The longer an event, the more your body will rely on the aerobic system. A strong aerobic base will even benefit one’s recovery in-between sets of strength training as well as anaerobic interval training too.
Many people, especially many “athletes” are running long distances with a very poor aerobic system, relying heavily on their anaerobic system to get them through their training. This anaerobic training is their “cardio” and it’s very, very unhealthy, which is part of the reason so many point to “cardio” as harmful to one’s health, especially when it comes to the immune and hormonal systems. So these anti-aerobic “cardio” gurus cite studies such as the one in the Canadian Journal of Applied Physiology in April 2004, “Intensive Swimming Exercise-Induced Oxidative Stress and Reproductive Dysfunction in Male Wistar Rats: Protective Role of Alpha-Tocopherol Succinate” to back up their claims. Well, if you’re making a rat (or a human) swim intensively for three hours a day, five days a week yeah there is going to be oxidative stress and hormonal dysfunction. (As a side note in this study, the researchers noted the free radical damage could be protected with vitamin E.)
But this doesn’t mean aerobic “cardio” is bad. Swimming intensely for three hours (gotta be a long time for a rat) is going to tax the anaerobic system pretty significantly. This is not “aerobic” – it’s chronic anaerobic “cardio.” When you’re constantly using your anaerobic system more than your aerobic system, it puts a major stress to your entire body – your nervous system, cardiovascular system, hormonal system, immune system, and digestive system – pretty much all of it. For example, if you’re out for a long run, say 30-60 minutes, and your aerobic system is very poor, then you might be running at say 70% anaerobic and 30% aerobic. But if you develop your aerobic system, then at that same pace you could flip the energy utilization to 70% aerobic, 30% anaerobic. You’re a much more efficient athlete. This is evident when using a heart rate monitor and seeing your HR lower at a given pace/exertion level than what it once was in weeks or months previously. If you have access to an exercise physiology lab and a gas analyzer you can measure your respiratory quotient – the level of aerobic (fat burning) vs. anaerobic (sugar burning) – occurring during your run or other workout.
Anaerobic Conditioning: Are You Ready? Probably Not
Type II, fast twitch muscle fibers are primarily anaerobic, (some are a mix of both fast and slow twitch), – they burn sugar and creatine phosphate and are more for power and speed. They’ll increase your mitochondria too, but the anaerobic system will fatigue much quicker than the aerobic system. High intensity workouts tend to be predominately anaerobic as is much of strength training due to various Type II muscle fibers being utilized and developed rather than Type I aerobic fibers. This however is a generalization, as some forms of strength training can also develop the aerobic system. Anaerobic activity incurs oxygen debt and a build-up of lactic acid; muscle imbalances and fatigue can result if continued. Muscle imbalances can been verified through certain manual muscle testing evaluations, (it’s a very accurate neurological assessment when performed correctly), as well as by visual inspection – one hip higher than the other or one shoulder rotated inwards, for example. Pain, poor performance, and injury often result from chronic muscle imbalances.
Essentially, you’re almost always using both systems, (the exception would be an all out sprint), depending on several factors which will be discussed later – exercise, diet, and lifestyle (overall stress levels). Anaerobic endurance and strength is essential in many circumstances and sports, but it is the aerobic system that will provide you with the endurance to work, play, think, sleep, and go several hours without food. Oh yeah, without a healthy aerobic system you won’t be a star in the sack – impotence & premature ejaculation for men and lack of sex drive as well as the inability to achieve an orgasm for both sexes is partly dependent on a healthy aerobic system (many other factors too).
Training Truly Aerobically
The line between predominantly aerobic and predominantly anaerobic is determined by your lactate threshold (LT). Below the LT you will be more aerobic than anaerobic, and above you will be more anaerobic than aerobic. True aerobic training is focused around lower-effort training zones 2 and 3, not the typical 3+ zone most are training their chronic “cardio” in. The “180-Age Formula” is also a great way to determine your aerobic training zone. Finding your heart rate zone is discussed more in Part II. Training around your LT too often is not a wise idea. Some call this area the “Red Line” or “Black hole” – it’s a great way to overtrain and should be left for hard days (hard group rides/runs) or racing days. A conditioned athlete may be able to endure this rate of exertion for well over one hour; whereas an unconditioned weekend warrior may be lucky to withstand fifteen minutes. Therefore, anaerobic training is often best performed as shorter, hard interval training above your lactic threshold, well into the anaerobic realm of training. This is where High Intensity Interval Training (HIIT) has its place. This will be discussed next in Part II along with developing your aerobic system regardless of your sport or goals.