Cigarette smoking related variation of heart rate and physical activity with ad libitum smoking under field conditions.

A recently developed device was used in a field study to continuously assess physical activity, heart rate, and cigarette lighting during 2 workdays and 2 days off in 12 female smokers and 12 female non-smokers. Heart rates did not differ between smokers and non-smokers or between workdays and days off; however, the nonsmokers showed significantly higher physical activity during the workdays. An averaging procedure used to obtain plots for smoking related changes of activity (SRA), pulse (SRP), and the pulse-activity ratio (SRpai) revealed four observations. a) "Lighting" responses consisting of parallel increases of SRA and SRP start a few minutes before lighting, reach a maximum with lighting, and drop immediately after lighting. b) The subsequent "smoking" responses last about 6 min and are characterized by a sustained postlighting SRA depression but immediate recovery of SRP, resulting in an increased SRpai level. c) Ten minutes prelighting and 10 min postlighting SRA and SRP are highly similar. d) The pattern of this response was similar for workdays and days off.