Physical activity may compensate for prolonged TV time regarding pulse rate—a cross-sectional study

Background. Regular exercise reduces pulse rate, but it is less clear how prolonged sitting time affects pulse rate. Our hypothesis was that high physical activity could compensate for prolonged sitting time regarding the pulse rate. Methods. Regression analysis was performed on cross-sectional data including 47,457 men and women based on two Swedish cohort studies, EpiHealth (18–45 years) and LifeGene (45–75 years). Self-reported leisure time physical activity was given in five levels, from low (level 1) to vigorous (level 5), and television time was used as a proxy of sitting time. Results. A higher physical activity (level 4 compared to level 1) was associated with a lower pulse rate in middle-aged females (-2.7 beats per minute [bpm]; 95% CI -3.3 to -2.2) and males (-4.0 bpm; 95% CI -4.7 to -3.4). The relationship between physical activity and pulse rate was strongest in the young. A prolonged television time (3 h compared to 1 h per day) was associated with a slightly higher pulse rate in middle-aged females (+0.6 bpm; 95% CI +0.3 to +0.8) and males (+0.9 bpm; 95% CI +0.7 to +1.2). Among participants with a prolonged television time (3 h), those with a high physical activity (level 4) had a lower pulse rate compared to those with a low physical activity (level 1). Conclusions. A prolonged television time was associated with a high pulse rate, while high physical activity was associated with a low pulse rate. The results suggest that a high physical activity could compensate for a prolonged television time regarding pulse rate.