Personal Training 7c: Cardiovascular Adaptations to Training

This post is part of an ongoing series about my learning process as I train to become a personal trainer.

The human body is a strange and wonderful thing.  It is also remarkably responsive to activity or movement.  In this mini-series, I look at the three main types of adaptation or change that occur when we exercise.  In the first post, I looked at the skeletal changes, in last week’s post I looked at the muscular changes and in this final week I’ll look at the cardiovascular changes.

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Cardiovascular changes

My course notes identify the adaptations by the type of exercise that causes them.  My textbook doesn’t do this but I’ll come onto that later.  My course notes are summarised in the table below, which shows the muscular adaptations to training and what sort of training causes them.

It classifies muscular strength training as anything up to 12 reps, with 2 -3 minutes rest.  Muscular endurance training is classified as 15 – 25 reps and cardiovascular training is everything else.  My course notes identify the adaptations by the type of exercise that causes them.  Here is a table showing the cardiovascular adaptations and what sort of exercise causes them:

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Reduced blood pressure

I have to admit that I nearly passed up the opportunity to question and investigate this point.  I nearly glanced over it, thinking, sure that sounds reasonable.  However, I resisted the temptation and did a little bit of digging.  I was surprised to find the following:

• This meta-analysis shows that muscular strength training does also cause reductions in blood pressure, which is nice.
• This simple study suggests that very little exercise is required to have a meaningful effect on blood pressure, which is also nice.
• However, this press release about a study suggests that in older adults, even a significant exercise programme made up of aerobic and resistance training does not have earth-shattering effects (watch out, because the title is a little misleading). 

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Reduced resting heart rate and increased stroke volume

Reduced resting heart rate is thought to occur from increased stroke volume so these could be considered as one point.  I have been less successful (spot the confirmation bias!) in finding any studies to suggest that resistance training is as effective at reducing resting heart rate as cardiovascular exercise.

• This study suggests that cardiovascular training is indeed more effective at reducing resting heart rate than resistance training.
• This study suggests that resistance training does create some adaptations to the cardiovascular system but a reduction in resting heart rate is not one of them.

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Reduced risk of heart disease

As above, I have not been able to find a strong trend of studies that suggest that resistance training is as efficacious as cardiovascular training at reducing the risk of heart disease.

• This study suggests that resistance training could help in the treatment of heart disease.
• And this study suggests that the effects of resistance training could be as much as those gained in cardiovascular training.
• However, this very recent meta-analysis suggests that the impact of resistance training is not really that great and certainly not as great as cardiovascular training.

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Increased size and number of alveoli and capillarisation around alveoli

This is getting way too technical for me.  Here’s Wikipedia on alveoli.  If you want to dive into this any further, you’re on your own.

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Increased haemoglobin in the blood

As I noted in my post last week, I am not sure whether any type of training apart from altitude training increases the production of red blood cells.  Indeed, a search I did showed that the vast majority of studies seemed to be about either altitude training or pharmaceutical intervention.  Here are two studies I noted last week, as they also relate to increased haemoglobin:

• In this rather amusing study, a group of five Beagles were subjected to an hour of maximal (!) treadmill exercise for 5 days a week for 6 weeks.  The result was that no increase in red blood cell mass, serum erythropoietin concentration, or any other blood cell index measured and the researchers concluded that this type of exercise conditioning does not produce the necessary stimulus for an increase in erythropoiesis.
• And in this study, a group of 7 male horses were subjected to 272 days of consecutive hard training to assess the markers for overtraining.  The horses showed some decline in muscle ATP concentration during maximal exercise but, interestingly, plasma volume, red blood cell volume, and blood chemical variables were unchanged.

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Increased recovery rate

 Well, yes.

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Reduced body fat

How easy it is to make the assumption that small and skinny is the same as having low body fat. 

• As Rachel Cosgrove points out, cardiovascular training often leads to a body with a higher fat percentage than resistance training.  I mean, come on.  Try and tell me that runners have lower body fat percentages than gymnasts…
• However, this interesting picture guide to different types of athletes’ appearances is a good sense check.  I think the use of pictures to show the different athletic body types is brilliant.  I don’t think the table of body fat percentages is quite right, though.

I would note that I think that it really depends on where you are starting from.  If you are starting from Michelin Man proportions, then cardiovascular training is definitely going to be where you get the best results.  However, if you are looking for body recomposition rather than simple reduction, then, unless you have freaky genes, cardiovascular training isn’t going to be what gets you there.

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As always, please let me know if you can shed any light on any of these areas for me.