Aerobic exercises -- "aero" means air by the way -- are exercises which increase your heart rate and are oxygen-fuelled. Exercises like running and swimming are aerobic-based, they get your heart rate up, a statement we understand to mean we suck in a lot more oxygen. It's true: during aerobic exercise we breath more oxygen into our lungs more often because we need more just to complete said exercises in the first place. Phew.
We don't often think about it, but there's not only different levels of fitness but there's also different types. Aerobic fitness is based upon our ability to utilise oxygen as effectively as possible -- the official term for this is cardiovascular fitness. One dictionary defines this as being "the ability of the heart, blood cells and lungs to supply oxygen-rich blood to the working muscle tissues and the ability of the muscles to use oxygen to produce energy for movement."
O-kay.
With anaerobic exercise though, oxygen alone is insufficient for supplying the necessary fuel-slash-energy to complete an exercise. Strength-training is anaerobic by definition because when we work out, we need shit-loads more energy than oxygen alone can provide and guess what? Your body knows that too, so it goes out and harvests said energy so you can move that barbell up and down, up and down for short, intense bursts.
The question is: what is this energy source?
...where does our body harvest said energy from?
Our bodies produce said energy via yours and my muscles breaking down the glycogen stored in our bodies into glucose -- also known as sugars -- and using this as fuel-slash-energy (NOTE: carbs are our main energy source as they get broken down quickly into glucose. Visit Nutrition basics to learn more. The short version is simply eat your carbs). Weight training is anaerobic precisely because we need energy faster than our bodies can deliver oxygen. Get it?
SO WHAT HAS ANAEROBIC OR AEROBIC GOT TO DO WITH WORKING OUT?
It stands to reason that you want your training to be more anaerobic rather than aerobic in the iron game. By forcing our bodies to tap into further fuel-slash-energy sources we're then capable of lifting heavier, fatiguing our muscles faster and thus, breaking them down further for repair. The theory behind this (and popular with bodybuilders) is by tearing the muscle -- actually working it hard enough to create small, microscopic tears in the physical tissue -- we will force it to recover and rebuild itself bigger and better.
...which occurs during rest days.
Chur.
Personally, I don't really care about the details or stretching muscle fascia because what I do know from my own experience is muscles get stressed by weight → muscles adapt to stress by growing stronger → stronger is almost always bigger → I don't give a shit how this happens → more stress can now be added → we repeat the fucking process → this is known as progressive overload.
...we all feel better.
But I digress.
When working out, is it really worth doing three sets of ten squats at body weight, the same that leaves you heaving for air, when you could do 3x5 with another 10-20kg added for the same or better results? You want to focus on overloading the muscle not your breathing capacity, plus time is precious. Yes, I'm biased towards low reps, but if you're getting the same or better results, why wouldn't you go for it?
HOW I MAKE ANAEROBIC WORK-OUTS WORK FOR ME
Firstly, as an older lifter, excessive lifting of heavy weights isn't what I'm about -- at least not week after week, and certainly not in large volumes. Whilst I no longer chase numbers (much) I do chase longevity which means protecting tendons, ligaments and the health of my body in general because my recovery isn't as good. In fact, my endurance isn't as good either. The point is, I don't want to hammer my body mercilessly, that's a young man's game, so sticking with a 5-rep range or triples, doubles and singles works for me.
Secondly, doing 5-reps means I have air in the tank when performing, say, heavy squats. I've noticed by upping reps with another 3-5 on top of, I will start sucking in air big time. This over-riding need for more oxygen impacts my form when lifting. That's a big no-no. By the time I put the bar down I'm somewhere between nauseous and hyperventilating. Is that even healthy for a guy my age? No. No it is not. In fact, I suspect it's not healthy for any fucking age (NOTE: please feel free not to contact me and explain how heaving for oxygen is important as I don't give a shit. Those are your goals not mine).
Sure, there's a time and place for the above but week in week out? Nah. Young man's game. "But your muscles won't grow unless you do x-amount of reps, brah". Bollocks. You can gain on all manner of programs and whilst some will be more optimal than others -- though I put forward they all even out once you reach your genetic potential -- you just may be one of those people where what's optimal for others isn't optimal for you (for the record, have you noticed the thighs on Olympic lifters? They are hyuuuuuge yet Olympic lifters do low volume triples, doubles and singles 247. Hm).
Thirdly, instead of heading towards more volume for a lagging body-part, why not do less volume with a heavier weight? This allows you to really hit the muscle, not over-stress yourself and also recover well afterwards. Naturally you wouldn't do this for smaller muscles like deltoids, biceps and the like which should be obvious but don't just fall hook, line and sinker for the idea that because you're older you can't lift heavy. Some powerlifters in my age bracket shift phenomenal poundage just like other lifters in my age drown when doing too much volume.
What's your sweet spot?
NOTE: what's heavy for me may not be heavy to you. What's heavy for you may not be heavy to someone else. Just go with what's heavy for yourself and leave aside ego and comparison. I've watched women shorter and smaller than me easily pull another 50-60kg more on deadlifts than I can and guess what? I thought it was awesome and felt really proud of them. They are stronger than me and I accept this just fine. Just saying is all.
CATABOLISM, ANABOLISM AND WORKING OUT ON AN EMPTY STOMACH
You also need to know that muscle goes through a constant process of breakdown and rebuilding in fact, this process occurs right across the human body -- skin is an excellent example of this, as it replaces itself roughly once per month. The breakdown of muscle tissue is called catabolism. The rebuilding of those tissues is known as anabolism. This normal process occurs automatically without our even being aware of it and has been going on since you were born, kemosabe.
Die hard bodybuilders are petrified of going catabolic during the night but the fact is, we all do. When we go to bed and sleep, we don't eat till morning so effectively we're actually fasting while we sleep (hence the term "break-the-fast" or breakfast). Because the body depletes glycogen to keep all systems operating when we're asleep, it can also cut into proteins-slash-muscles to harvest energy i.e. a catabolic state. We may indeed lose a little "tissue" here and there.
There's fuck all you can do about this.
So when strength-training (which is anaerobic) we use up enormous amounts of glycogen and if we use it all, our bodies will again harvest protein-slash-muscle to provide energy. This is gets tricky when you consider working out on an empty stomach. A lot of lifters will ingest some sort of protein intake prior to working out precisely because they fear entering a catabolic state. They fear depleting their glycogen reserves thus causing their bodies to harvest energy from muscle tissue.
...is this even true?
Is it wrong to work out before a meal?
Personally I'm not so sure BUT plenty of people say it is.
For the record, I always work out before eating first thing in the morning and I'm good with it. Ironically, there's also a whole slew of people (like moi) on the other side of the fence who say that working out on an empty stomach is great as it causes your body to tap into stored body-fat for its energy source. Is that even true? Fuck knows I mean, it's not like your body is calling your cellphone and leaving a message, huh? I simply work out first thing in the morning because of the time factor. My wife and I are running a family here and time is precious.
Anyway, after working out many lifters will again have some sort of protein-amino intake so as to provide necessary nutrients for the muscles to recover. Is this also true? Do muscles really need to be "fed" protein straight after? Again, I'm not so sure and to be honest don't give a shit as I find this level of obsession quite silly but hey, that's just me. What I do know is quite a few bodybuilders recommend getting the majority of your daily carb fix in straight after your work-outs so as to replenish glycogen levels, which makes a bit more sense.
Do I do that? Fuck no.
At the end of the day I think you should make your own mind up or, if you really want to be scientific about it, try working out on an empty stomach for a month and see how you look, feel and think about it. Can you move more weight? Do you feel better? Does your garter belt and your panty-hose stay up? Then do the reverse: work out after a meal or some form of pre-work out "fix", and assess yourself similarly. Whichever works best would obviously be your new go-to.
:: CONCLUSION
To recap, aerobic means primarily oxygen-based: your body is getting enough oxygen to power itself without having to tap into any other alternative fuel-slash-energy source. Hence the reason aerobic-type exercises can be referred to as steady-state cardio or being endurance-based. Anaerobic exercise is much, much shorter and more intense; it uses shit-loads more energy in short bursts only. You'll last a lot longer aerobically than you ever will anaerobically, simply because the muscular demand for the latter is too high.
Think of it this way: which do you think you could do the longest, walk or benchpress? We both know you could walk longer than you could benchpress. But. Out of the two, which will build the most muscle? Obviously benchpress. So. Are you benching, pressing and squatting heavy-enough poundage so that your work-outs are short, sharp and sweet because you've given it heaps? Or are you just "getting your heart rate up" i.e. improving your cardiovascular system and doing nothing much for your physicality? For strength and muscular development (hypertrophy), I put my money on anaerobic-based work-outs every time.
Thanks for reading and stay informed. Kia ora whanau.