Walking in the evening improves cardiovascular markers better than walking in the morning

Walking is beneficial any time of day, but an interesting study published recently in the journal Preventive Medicine demonstrated significantly more improvement in some key cardiovascular lipid and inflammatory markers by walking in the evening versus in the morning. The authors set out to:

"...examine the influence of walking at different times of day on lipids and inflammatory markers in sedentary patients with coronary artery disease (CAD)."

They measured lipids and inflammatory markers data 330 patients evenly divided into a control group, morning or evening walking group who were asked to walk 30 min/day or more on at least 5 days/week either in the morning or evening before and after 12 weeks. Walking in the evening proved to have significant advantages:

"Compared with baseline, total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C) and high-density lipoprotein cholesterol (HDL-C) were improved in all groups. Significances were shown in the changes of fibrinogen, high sensitivity C-reactive protein (hsCRP), white blood cell (WBC) count, TC, triglycerides, LDL-C, lipoprotein(a) between groups. The evening walking group had a larger decrease in fibrinogen, hsCRP, WBC count, and LDL-C than the other two groups."

Note that all groups were rewarded with improvements in cholesterol levels, so better to walk anytime than not at all. These data, however, suggest their may be some additional benefit to walking in the evening when possible. Whether this is due to circadian effects on cortisol levels, more of a parasympathetic reaction, or other factors remains to be seen. The authors conclude:

"Our walking program successfully resulted in a favorable change in lipids and inflammatory markers. Patients in the evening walking group gained more benefits than those walking in the morning walking group."