Does hot blood flow faster?

Posted on 2014-10-19
Last Modified: 2014-11-05

When we warm up for exercise we raise out body temperature to do thinks like thin the synovial fluid for range or motion

But the blood gets hotter - so you'd think it flows faster?
But if we sweat and do not dehydrate the blood get more viscous i presume and flows slower making exercise harder

Is this correct?
What other benefits does hot blood have on exercise (no innuendos please )

Question by:andieje
  • 2
  • 2
  • 2
  • +1
LVL 142

Accepted Solution

Guy Hengel [angelIII / a3] earned 500 total points
ID: 40389892
if it flows faster, it's not because it's hotter, but because the heart is feating faster...
it may also flow easier because the blood tubes get a bit larger (due to the temperature increase), but compared to the heard beat increase this has much lower impact

but having the blood running faster there will be faster (and hence more) transportation of oxygen and other nutritional "stuff" to the organs that need it, and faster off-loading of the "crap" generated that has to get off (CO2 etc)
LVL 24

Expert Comment

ID: 40389962
First, the blood doesn't get hot. Second your ideas about its viscosity is also incorrect. It's better to leave medical theories to trained researchers; as such speculations, if believed and acted upon, are dangerous.

Thanks and Regards.
LVL 84

Expert Comment

ID: 40391114
Your body will try to regulate blood temperature within a limited range.
Within that range, the effect of temperature on viscosity should be small.
Outside of that range, your body may have more pressing concerns than viscosity.

Sweating is one of the ways that your body may use to regulate temperature.
But excess dehydration can increase blood viscosity, which can be one of the dangers of excess dehydration.

Your heart will try to maintain blood flow required to supply to meet the oxygen requirements of tissues,
which tends to increase with exercise.
Blood viscosity can have an effect on the effort required to maintain this flow, but blood vessel dilation would usually be a greater factor.
Blood vessel dilation would allow greater flow at lower velocities which eases the effort required to maintain desired flow.
Courses: Start Training Online With Pros, Today

Brush up on the basics or master the advanced techniques required to earn essential industry certifications, with Courses. Enroll in a course and start learning today. Training topics range from Android App Dev to the Xen Virtualization Platform.

LVL 27

Expert Comment

ID: 40391122
The viscosity of blood is definitely meaningful (see, e.g., Blood Viscosity (Hemorheology) and others) , though it should only be minimally related to general exercise and common dehydration in a reasonably healthy person.

And blood being "hot" should only be considered as a relative description. Blood temperature will vary as thermoregulation takes place, and it will correlate with core temperature. In that sense, it does get "hot".

One mitigating factor will be dilation of blood vessels at large areas of skin that act as heat sinks. As the vessels widen, flow rate should increase. I'd expect that to be one of the largest factors, one that would more than offset any effect from normal dehydration through exercise.

LVL 84

Expert Comment

ID: 40391142
Indeed, long term effects of exercise on blood viscosity may be more interesting than short term effects.

But if the original question is "Does hot blood flow faster?" I would say that the body's efforts to regulate excess temperature would generally tend to increase blood flow (assuming that "faster" refers to flow rather than velocity)
LVL 27

Expert Comment

ID: 40391168
Agreed. Terminology might be tricky, so velocity can be inappropriate. Increased heart rate with decreased resistance (i.e., dilation) could seem to contribute to velocity, and it seems reasonable that elevated circulation rate would be an objective for regulation. But it might not actually translate to 'velocity'.

LVL 24

Expert Comment

ID: 40391990
Many medical researchers (experts?) on Experts Exchange.  ;-)

Is there enough interest to open a new topic of "medical advice"?  Sorely needed by all.

Featured Post

Live: Real-Time Solutions, Start Here

Receive instant 1:1 support from technology experts, using our real-time conversation and whiteboard interface. Your first 5 minutes are always free.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Suggested Solutions

Title # Comments Views Activity
Probability Distribution 5 48
Sample Space 12 46
Odds of picking games correctly 4 88
Lock or digital lock that are lockable from both inside plus outside 12 51
How to Win a Jar of Candy Corn: A Scientific Approach! I love mathematics. If you love mathematics also, you may enjoy this tip on how to use math to win your own jar of candy corn and to impress your friends. As I said, I love math, but I gu…
This article seeks to propel the full implementation of geothermal power plants in Mexico as a renewable energy source.
This is a video describing the growing solar energy use in Utah. This is a topic that greatly interests me and so I decided to produce a video about it.
Although Jacob Bernoulli (1654-1705) has been credited as the creator of "Binomial Distribution Table", Gottfried Leibniz (1646-1716) did his dissertation on the subject in 1666; Leibniz you may recall is the co-inventor of "Calculus" and beat Isaac…

816 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question

Need Help in Real-Time?

Connect with top rated Experts

8 Experts available now in Live!

Get 1:1 Help Now