A Guide to: Cardio

What is Cardio?

• Short for cardiovascular exercise, is an activity that gets your heart rate up and blood pumping . usually above your resting heart rate 
• A normal, healthy resting heart rate is around 60-100 bpm.

• The types of cardio
• Cardio can be anything involving movement: walking, running, swimming, tennis, jumping jacks, rowing, even rolling around in a field is cardio!

• Which cardio is for me?

• Which cardio suits you depends on: whether you have any disability/impairment, any health conditions and fundamentally, what you enjoy doing – if you’re going to adopt cardio into your routine you’re going to want to enjoy it.
• Personally, my favourite cardio exercise is the incline treadmill – it’s great because I find long walks relaxing and passive. This type of cardio is great for letting your mind wander, as opposed to cycling for example, which requires more concentration and input.

• Which exercise burns the most calories in 5 minutes?

• Zumba = 39
• Biking 14-16 mph =52
• Dancing = 29
• Elliptical = 56
• Hiking = 29
• Jumping rope = 49
• Light yoga = 20
• Pilates = 25
• Rock climbing = 54
• Rowing = 43
• Running at 6mph = 49
• Step machine = 34
• Moderate swimming = 30
• Tennis = 30
• Walking at 4mph = 25
• Weight lifting = 30
• Mopping/Sweeping = 39
• Doing laundry = 5-10
• Doing the dishes = 6
• Rolling on the floor = TBC

• isn’t lifting weights cardio?

• Why, yes it is! – However, there is a reason why runners don’t swing kettlebells around to train for a 5k, and the reason is multifaceted:
• 1) Your body tends to improve whichever activity it repeats, this is the old adage “practise makes perfect” so, it makes sense that you would run to get better at running, just like you wouldn’t practise your handwriting by practising tying knots.
• 2) The more physiological reason – weight lifting and typical cardio are usually differentiated by the terms “anaerobic” and “aerobic”, exercise isn’t this black and white categorical activity it will usually fall somewhere on a sliding scale in between the two;

A completely (hypothetical) anaerobic exercise will use *zero* oxygen and *only* glucose to complete the exercise. 

A completely aerobic exercise will use both glucose AND oxygen. It is this oxygen use which makes it a cardio activity and what makes weightlifting not-quite-cardio which mainly relies on energy stores and blood sugar.

Okay, so why the (hypothetical)? – this is just a disclaimer, because in reality the body will use a negligible, but non-zero amount of oxygen before it then starts to use solely glucose.

We will explore reason 3) in the next question…

• How does cardio make you healthier?
• Good question, not only this but does it make you healthier than weight lifting?

To answer this I will break the question up into 2 parts:

1. How does it make you healthier? This isn’t intended to be an essay site on fitness, so I will save both of us time by giving a concise(ish) version….We’ve all heard about the benefits of getting on the treadmill, but we are rarely told just WHY and HOW getting on the treadmill will help your heart. 

Very basically, your heart is a muscle just like the other well known ones in your body (it is slightly different but that’s a story for another day). Your heart also adapts itself after intense exercise to better cope with a future event of similar intensity – the heart muscle thickens, specifically the walls of the left ventricle (the chamber responsible for expelling oxygen-rich blood from the heart and to the rest of the body). This thickening allows more blood to be “pumped” per beat, this means you can progressively move more blood with fewer heartbeats and thus your resting heart rate lowers.

There are many more health benefits to cardiovascular exercise, too many to go into sufficient detail. However, there is one I’d like to talk about and that’s the long-term lowering of blood pressure.

1. The strengthening of skeletal muscle allows the blood around the body to be allowed to be squeezed out more easily, thus reducing the effort of the heart.
2. The body starts to produce more Red Blood Cells to carry the oxygen more readily in the bloodstream, at rest this means your heart can beat more slowly because more oxygen is being transported per pump.
3. In conjunction with the point above, the lungs also become more efficient allowing more oxygen to enter the blood in the first place.
4. Stress hormones such as cortisol and adrenaline cause blood pressure to increase, exercise can also reduce these hormones leading to a cardiovascular system in a less-stressed state. 

• How much cardio should I do?
• Not too much, as we will see later. Usually, you should aim for about 30 minutes per day if you’re not an athlete (If you are an athlete then the next question will be especially important to read)

• Is there such a thing as too much cardio?
• Yes, there is such a thing as too much of something good and exercise is one of those things.

1. Too much exercise can cause overtraining – this is where you tax your body beyond its fitness capabilities and as a result it will make you feel unwell, although the severity depends on how far you push yourself. For the most part though, it should subside after a few days.
2. Too much exercise (in athletes) can cause changes in the heart muscle – leading to potentially fatal arrhythmias.
3. Too much exercise can cause a condition known as Rhabdomyolysis – this is a condition where your skeletal muscle cells break down and release of myoglobin – that red stuff that oozes out of steak.

• What if I can’t do “x” cardio?
• If you can’t do cardio for a medical reason then you shouldn’t be doing cardio. If your doctor thinks that exercise isn’t conducive to a better quality of life for you then heed their advice!

However, if you can safely perform strenuous aerobic activity, then you should be able to choose an exercise best suited to you no problem.

• When should I do cardio?
• We will start with: When should I NOT do cardio.

You should avoid cardio at these times:

1. Directly before bedtime
2. After a long period of fasting
3. Before a weight lifting session
4. After a heavy meal

The logic follows then that you should do your cardio after a small meal, or sufficient (2-3hrs) time after a larger meal. In the morning is usually best, not just for fat loss but for improving your mood as well for the day ahead.

Also, avoid cardio before weights as the cardio will put your body in a state of catabolism and thus impede muscle growth. If you are going to cardio on the same day, do the cardio after your weight session and ensure that the cardio is no longer than HALF the length of your weight session. 

• Will cardio make me lose muscle?

• Short answer, Yes. 
• Longer answer, Not always.

1)  Yes, because cardio activity is by its nature a Catabolic process, being in a calorie deficit and using muscle tissue as fuel is another reason. The reason you don’t see Mr.Olympia competitors doing marathons is the same reason you don’t see olympic long distance runners setting powerlifting records – Muscle.

Muscle is denser than fat, if you swapped all of the fat in your body for an equivalent volume of muscle your BMI would be incredibly high – in fact this is the reason BMI measurements are flawed, they are only accurate for untrained individuals.

Why did I side-track to BMI? – WEIGHT that’s why.

Moving heavier weight burns more calories – do you see where I’m going here?

2) While it’s true that cardio and muscle building aren’t great friends, there is a happy medium as we will find out in the next question.

• Can cardio benefit me on a bulk? Yes it can and this is how to use it to your advantage on your bulk:

1. Via a process called “active recovery” it can help speed up muscle repair by supplying more nutrient-rich blood to the damaged area.
2. It improves insulin sensitivity which promotes better absorption of nutrients in the muscle and deters fat storage – contributes to a “leaner” bulking phase.
3. Some forms of cardio are better for bulks than others. For example – HIIT cardio, this form of cardio is short, but intense and can help preserve muscular gains and help mitigate loss that you might see with longer, more moderate forms of cardio.
4. You want to aim for no more than THREE cardio sessions per week when you are bulking, the reason for this is it CAN eat into your weightlifting performance, again, balance is everything with fitness and in life in general. *The “three times per week” advice is a guideline, people vary in what suits them and in what they have the best results with. Perhaps start with 3x per week and adjust as you see fit.

• Can cardio make you less stressed and happier?

• There is a hypothesis that people who suffer from depression and/or anxiety disorders have low levels (saying “low levels” is very reductionistic and is a common buzz term amongst talk of the major neurotransmitters, however, it paints a simple picture of the situation without deviating too far from the complex truth).
• Cardiovascular exercise in particular raises your levels of endorphins in the brain.
• Endorphins are neurochemicals in the body that work similarly to Opioids such as morphine – they relieve pain and can induce euphoria.
• These chemicals are produced in the body and work similarly to Opioid drugs, but without the risk of addiction and overdose.
• This is what causes the “runners high” we’ve all heard about. 
• Believe it or not, regular cardio, for 20-30 minutes per day is recommended by doctors for mild-to-moderate depression and anxiety symptom relief.

To summarise:

1. Cardio is exercise that gets your heartrate up.
2. Cardio isn’t a specific exercise, almost anything can be cardio.
3. The elliptical is one of the best cardio exercise machines to use.
4. Lifting weights does improve cardio fitness, but not as much as cardio targeted (aerobic) exercises.
5. Cardio is VERY good for you, however you can overdo it.
6. You should aim for about 20-30 minutes of cardio per day.
7. (Generally) Make sure you’re well fed, rested and warmed up before participating in cardio.
8. Cardio can be a great way to recover more quickly on a bulk, especially if the muscles in need of repair are used in the cardio exercise.
9. What cardio can do for your health in summary:

• Decreases stroke risk
• Improves memory and cognition
• Reduces age-related cognitive decline
• Increases bone strength
• Increases joint mobility
• Improves skin health
• Increases sexual function
• Great for mental health
• Deeper and more restorative sleep.