Some time ago, the GFit team were asked by a large steel manufacturer to conduct an experiment on the positive effects of quitting smoking.  We only had three days to do it, and a shoe string budget, but our findings in just three days of quitting smoking were quite profound.

We had a small sample group of six participants, three who had quit smoking the day before the three day experiment (quitters), and three who had continued to smoke.  Each participant was monitored with specialist heart rate monitors, continually for a seventy two hour period.  Each participant underwent a daily group exercise programme, in which the intensity and volume was kept constant on each day.

There was a lot of data gathering and technical stuff which I won’t bore you with, but in a nutshell, here were our observations. (note, because the sample group was so small, the time frame was short and we didn’t have the budget to control for all variables, results have not been independently verified. Nevertheless, the observations make for interesting reading.)

  1. Heart Rate
  • In the three quitters, the average daily heart rate came down by 17% from Day 1 to Day 3.
  • Maximum heart rate during the most intense exercise periods came down by 6%.
  • There were no significant changes evident in the smoking group.
  1. EPOC
  • This is a measure of post exercise recovery.
  • Quitters showed a massive 45% improvement in the rate of recovery on Day 3 vs Day 1.
  • It also took significantly longer for their heart rates to become elevated during exercise on day 3, indicating improved cardiovascular fitness.
  • Smokers showed no significant improvements.
  1. Stress
  • Our monitoring devices measure heart rate variability and the extent to which the heart is under stress.
  • The quitters showed a 34% improvement in heart rate variability, indicating that the heart is pumping more efficiently, delivering greater volumes of blood and oxygen with less effort.
  • These changes were not evident in the smokers’ group.

Reasons for Change

We proposed that the reasons for the observed changes may include the following:

  • Improved oxygenation of blood resulting in improved cardiovascular functioning, improved oxygen delivery to cells and greater levels of output with less stress put on the heart.
  • Decreased sympathetic neural drive. The sympathetic nervous system controls things like blood pressure, heart rate and breathing. Smoking enhances sympathetic activity leading to elevated blood pressure, heart rate and breathing.  By stopping smoking a more restful neural state is achieved.
  • Decreased blood pressure as a result of decreased sympathetic neural drive.
  • Greater availability of “protective” nitric oxide of blood vessel walls when you stop smoking, resulting in greater expansion of blood vessels and improved oxygen delivery to cells.

The most significant long term effects of quitting smoking are:

  • Greater cardiovascular capacity
  • Improved recovery after cardiovascular loading, eg after a hard day’s physical work.
  • Significantly less strain on the heart during a state of rest and stress.
  • Increased physical productivity.
  • Predicted reduction in absenteeism.
  • Significantly reduced health risk.

The magnitude of the improvements really surprised us, and although the results may not be considered to be scientifically valid, we would really love to do something similar again on a larger scale over a longer time frame.