By Harold L. Karpman, MD, FACC, FACP

Clinical Professor of Medicine, UCLA School of Medicine

Dr. Karpman reports no financial relationships relevant to this field of study.

SYNOPSIS: Joggers who perform light and moderate jogging programs have lower mortality than sedentary non-joggers, whereas strenuous joggers have a mortality rate not statistically different from that of the sedentary group.

SOURCE: Pate RR, et al. Physical activity and public health. A recommendation from the Centers for Disease Control and Prevention and the American College of Sports Medicine. JAMA 1995;273:402-407.

Over the years, hundreds of articles have been published about the positive effects of physical activity on the rate of occurrence of cardiovascular disease and its mortality. In 1965, the President’s Consul on Physical Fitness published a recommended program and, since then, numerous studies have strongly supported the finding of an inverse relationship between the degree of regular exercise and mortality, demonstrating that physically active men and women have an approximately 30% lower risk of death compared with inactive people.1-4

In 1969, the first running race in Europe (the Eremitage Race) took place in Denmark. Unfortunately, one of the 2344 participants, a 46-year-old naval officer, died of a myocardial infarction during the event. The race has continued despite the event organizers’ initial concern that the 7.6 mile course was too strenuous and possibly even dangerous for the general population, but, of course, since that time, numerous reports of death during jogging have been published.5-10

The Copenhagen City Heart Study is composed of a random sample of 19,329 Caucasian men and women between 20 and 93 years of age drawn from the Copenhagen Population Register as of January 1, 1976. This study revealed that the relative intensity of walking and cycling, and not the duration, was of most importance in relation to all-cause and coronary heart disease mortality, and that the increase in survival among joggers was on average 6.2 years in men and 5.6 years in women.10,11

Schnohr and his colleagues re-analyzed the data of 5048 men and women (1098 healthy joggers between 20 and 81 years of age and 3950 healthy non-joggers) who were followed for 12 years.12 The joggers were categorized into three groups: light, moderate, and strenuous joggers. The detailed analysis revealed that the optimal frequency of jogging was 2-3 times per week, resulting in a total of 1-2.4 hours of jogging per week; the optimal pace was slow or average; and the lowest hazard ratio for mortality was found in light joggers, followed by moderate joggers and strenuous joggers.

The results suggested a U-shaped association between all-cause mortality and the dose of jogging, as calibrated by pace, quantity, and frequency of jogging. Light and moderate joggers had lower mortality than sedentary non-joggers, whereas strenuous joggers had a mortality rate not statistically different from that of the sedentary group.

COMMENTARY

There seems to be little question that exercise improves health, decreases mortality, and contributes to longevity. With respect to running, a study of 55,000 adults between ages 18 and 100 years of age who were followed for a mean of 15 years reported that runners, as compared to non-runners, had 30% and 45% lower risks of all-cause and cardiovascular mortality, respectively, with a mean improvement in life expectancy of 3 years.13

However, the Schnohr study revealed that although joggers as a group appeared to live longer than sedentary non-joggers, light and moderate joggers have lower mortality rates than sedentary non-joggers, whereas strenuous joggers have a mortality rate that is not statistically different from that of the sedentary group. The U-shaped association suggests the existence of an upper limit of jogging exercise that is optimal for health benefits if the goal of jogging exercise is to decrease the risk of death and improve life expectancy.

Going for a leisurely jog a few times per week at a moderate pace appears to be good strategy; however, it must be recognized that higher doses of running are not only unnecessary but may actually diminish some of the longevity benefits conferred by lower doses of running. In the Schnohr study, the dose of running that was most favorable for reducing mortality was jogging 1-2.4 hours per week performed on no more than three running days per week at a slower average pace. This goal appears to be quite practical, achievable, and sustainable for most men and women.

In summary, in a large random sample of men and women, joggers appear to live longer than sedentary non-joggers.12 Moderate joggers had a lower mortality rate than sedentary non-joggers, whereas strenuous joggers had a mortality rate that was not statistically different from that of the sedentary group. The U-shaped association suggests the existence of an upper limit of benefit for exercise dosing that is optimal for health benefits. The results of the Schnohr study suggested that higher doses of running are not only unnecessary but may actually diminish some of the remarkable longevity benefits conferred by lower doses of running activities. It should be recognized though, that the Schnohr study was an observational and not a randomized controlled study and, hopefully, these results will be confirmed by a full-scale randomized, controlled study at some time in the future.

REFERENCES

1. Adult Physical Fitness: A Program for Men and Women prepared by the President’s Council on Physical Fitness. Washington, DC. President’s Council on Physical Fitness (1965), 1965:64.

2. Pate RR,et al. Physical activity and public health. A recommendation from the Centers for Disease Control and Prevention and the American College of Sports Medicine. JAMA 1995;273:402-407.

3. Haskell, WL, et al. Physical activity and public health: Updated recommendation for adults from the American College of Sports Medicine and the American Heart Association. Circulation 2007;116:1081-1093.

4. Physical Activity Guidelines for Americans. Washington DC: US Department of Health and Human Services, 2008:1-76.

5. Opie, LH. Sudden death and sport. Lancet 1975;1:263-266.

6. Thompson PD, et al. Death during jogging and running. A study of 18 cases. JAMA 1979;242:1265-1267.

7. Waller BF, et al. Sudden death while running in conditioned runners aged 40 years or over. Am J Cardiol 1980;45:1292-1300.

8. Siscovick DS, et al. The incidence of primary cardiac arrest during vigorous exercise. N Engl J Med 1984;311:874-877.

9. Albert CM, et al. Triggering of sudden death from cardiac causes by vigorous exertion. N Engl J Med 2000;343:1355-1361.

10. Schnohr P, et al. Intensity versus duration of walking, impact on mortality. The Copenhagen City Heart Study. Eur J Cardiovasc Prev Cardiol 2012;19:73-80.

11. Schnohr P, et al. Intensity versus duration of cycling, impact on all-cause and coronary heart disease mortality: the Copenhagen City Heart Study. Eur J Prev Cardiol 2012;19:73-80.

12. Schnohr P, et al. Dose of jogging and long-term mortality. The Copenhagen City Heart Study. J Amer Coll Cardiol 2015; 65:411-419.

13. Lee DC, et al. Leisure-time running reduces all-cause and cardiovascular mortality risk. J Am Coll Cardiol 2014; 64:472 -481.