February 22, 2010 | Graham

Push bikes and blood pressure



This is a piece of quasi medical research.

I’m wondering if anyone has had the same experience as me. After a lifetime of good blood pressure a few years ago it suddenly just jumped up to 160 over 100. My doctor said that unless I could reduce it he would prescribe medicine, and to help me get on top of it he recommended that I buy a blood pressure monitor.

The increase was a surprise to me. I wouldn’t call myself a “gym junkie” but many people would say I was disgustingly fit, particularly for a man my age. I run, lift weights and surf regularly and police my weight so that it is pretty close to ideal for a person my build. My resting pulse rate is generally quite low.

Observation of my blood pressure over the last couple of years  suggests some factors which influence it. Number one factor is salt. I now run at “high normal” with a systolic reading generally of 130 to 140 and diastolic of 80 to 85. It came down fairly quickly by reducing my salt intake significantly.

Other factors are alcohol – lowering it immediately after consumption but increasing it significantly the next morning – and exercise.

It is exercise that is the point of this post. A typical gym session for me consists of 30 minutes of heavy weights, 35 minutes of  running during which I’ll typically cover 6.5 to 7 kms and 20 minutes of stretching. A couple of hours later the exercise effect on my blood pressure will be somewhere around 10 points for both systolic and diastolic.

The effect appears to be short and long term. If I don’t exercise for a period of weeks then my blood pressure starts to creep up.

However, I’ve recently started riding a push bike to work, something which I tried a year or so ago too. That’s half-an-hour of riding in and out, counting stops at the lights and a journey distance of somewhere around 12 kms total. The effect on my blood pressure appears to be more dramatic than that of my usual vigorous exercise regimen.

I’m wondering if others have had the same experience. And if they have, what it is about push bike riding that might make the effect greater. I have two theories. One is that it’s causing me to sweat more so that the salt content of my blood is lower, thus reducing blood pressure. The other is that the stop-start nature of bike riding, particularly those frantic dashes in the right-hand lane, rushing to make a turn and worried that the semi behind you won’t slow sufficiently, provide a superior exercise effect.

And as I like to know what I am talking about, and as  my sample at the moment consists of insufficient data, being just me, I thought I’d throw the issue out to the blogosphere.

You never know. If there is something in this we might be able to convince Health Minister Roxon to subsidise push-bike purchases as a contribution to preventative health.



Posted by Graham at 12:49 am | Comments (8) |
Filed under: Health

8 Comments

  1. As a cyclist it probably the lower intensity of the work out riding your bike to work. Cyclists do weeks of long low intensity i.e. 60% of max heart rate rides to build base load fitness before high intensity work outs to build power or speed. Otherwise known as junk miles.

    Comment by Armon — February 22, 2010 @ 4:46 am

  2. I am 50 and reasonably active. My blood pressure has always been “excellent”. I weaned myself off a high salt diet in my late teens during an brief experiment as a vegetarian. Voluntary running (jogging) and gyms have never appealed to me. I do ride my bike a few times a week 15 km each way commute in the warmer months and play vet’s rugby (usually in the back line) every few weeks between Feb and Oct. Both activities are, as you have noted, stop-start, with periods of relaxing and periods of intense activity.

    So, you can add another anecdotal data point in favour of your hypothesis.

    Comment by Anthony David — February 22, 2010 @ 9:52 am

  3. Graham, dad confronted this same issue a few years back. He started riding a bike up and down our mountain in response to slightly high blood pressure but noticed that the high-level exercise made it more volatile. When he scaled back to moderate riding – along the flat roads at the foot of the mountain rather than up the steep part – things stabilised for him. He how rides on the flat parts for 30-45 minutes every day.

    He had reached an age where Plantar Fasciitis made jogging very unpleasant and has never been a fan of gyms or pools, so riding a bike was a good solution. Of course, he’s 20 years older than you, so you probably don’t need to scale back that much just yet … :-)

    Comment by Hughie — February 23, 2010 @ 12:52 am

  4. I’d always had a perfectly normal blood pressure until last year, when it was pronounced high and I was given medication to take. Sorry I can’t remember the systolic/diastolic figures.

    I’d been a fairly regular cyclist for some 3-4 years before this happened, and I still am – mainly commuting, some weekend riding, 1-2 long trips a year.

    So I can’t say that cycling has kept my BP normal. It’s also possible that the BP would be worse if I weren’t as active as I am. I eat a fairly low-salt diet – but salt and sugar do creep in with things like bread and other processed food.

    Comment by David B — February 23, 2010 @ 12:53 am

  5. PS – I should add that I’m in my 60s.

    Comment by David B — February 23, 2010 @ 12:55 am

  6. Hmmm. Not sure that my theory is going well here. I wonder what large scale experiments there are on exercise and blood pressure. I find it odd that it can suddenly go high. I would assume that high blood pressure has to do with the walls in the arteries being too rigid, but this doesn’t seem compatible with a sudden deterioration. Or with people who still have good fitness and performance – you’d think the blood pressure would inhibit performance.

    But David B and I appear to be examples of quite fit males who have suddenly developed high blood pressure. Makes you wonder about whether the recommendations for regular exercise really do much.

    And maybe I should swap the bike for medication.

    Comment by Graham — February 23, 2010 @ 12:44 pm

  7. Graham,
    I have ridden a bike for the last 20 years and my BP has always been stable.
    I’m wondering if the effect could be not so much the style of exercise but that we ride to and from work. I like to describe it as getting the corpuscles flowing. I know that when i don’t ride i feel more lethargic and less “alive”. also the ride home tends to dissipate stress acquired during the day.
    I guess the other aspect is the opportunity for contemplative thought provided by riding to and from work. Nothing scientific just observation but once you start riding to work you’ll never go back.

    Comment by barney — February 24, 2010 @ 12:46 am

  8. Is it avoidable if your family has a history
    of high blood pressure?

    Comment by Mackenzie Hernandez — April 29, 2013 @ 9:12 am

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