A recent US study published in the JAMA Network Open examined how higher cardiorespiratory fitness can lead to a longer life.
Research has shown the numerous benefits of regular exercise for overall health. Being physically active has been linked to improved fitness, lower incidence of disease, and better mental health, among other things. Aerobic exercise, in particular, has been shown to lower the rate of diabetes, stroke, cancer, hypertension, and coronary artery disease.
Aerobic, or cardiorespiratory fitness, refers to the body’s ability to deliver oxygen to the muscles during sustained periods of activity through the circulatory and respiratory systems. Types of aerobic exercise include jogging, swimming, cycling, rowing, and more. Some recent studies have raised concerns about the effects of overly aggressive exercise.
In a recent US study published in the JAMA Network Open, researchers examined how higher levels of aerobic fitness were associated with longer lifespans. The study analyzed historical data of 122,007 patients who underwent exercise treadmill testing at the Cleveland Clinic from January 1, 1991, to December 31, 2014.
Study participants were divided into groups based on fitness level: low, below average, above average, high, and elite. In each group, researchers looked at the relationship between the individuals’ cardiorespiratory fitness and all causes of mortality. The analysis also accounted for differences in participant age, sex, height, weight, BMI, medications, and other preexisting health complications.
Extreme levels of fitness had the most long-term health benefits
The results demonstrated that better cardiorespiratory fitness was directly associated with lower long-term mortality. The research also showed no upper limit to the positive benefits of aerobic fitness, and that extreme levels of fitness actually had the most long-term health benefits.
Elite level performers (those in the top 2-3%) had an 80% lower mortality risk than patients with low aerobic fitness. The study found that the mortality risk of poor cardiorespiratory fitness was equal to or greater than traditional risk factors such as cardiovascular disease, diabetes, and smoking.
They also evaluated each performance group by age and the presence of co-existing health conditions that could affect study outcomes. Patients 70 years or older with elite levels of aerobic fitness had a nearly 30% lower risk of mortality than those with high levels of fitness. In younger age groups, elite and high-level performers did not have significantly different risks of mortality.
When analyzed by comorbidities, elite level performers had the lowest rate of mortality from all causes when compared to other performance groups. In patients with hypertension, elite performers also had a 30% lower rate of all-cause mortality than high-level performers. The mortality risk between elite and high-level performers in other comorbid subgroups was not significantly different.
Cardiorespiratory fitness provides benefits regardless of age, sex, or existing health conditions
Patients with elite aerobic fitness had substantially lower levels of co-existing health conditions than other groups. However, this was not the case for those with hyperlipidemia—a condition defined by elevated levels of fats such as cholesterol in the blood. The rate of hyperlipidemia was not substantially different between performance groups.
Aerobic fitness appears to lower the long-term risk of mortality, especially at extreme levels. Higher cardiorespiratory fitness provides health benefits regardless of age, sex, or presence of existing health conditions. Health care professionals should encourage patients to improve fitness levels. Further research on the health benefits of exercise can help determine other factors contributing to mortality risk.
Written by Braydon Black, BSc
- Cleveland Clinic. Aerobic exercise [Internet]. Cleveland: Cleveland Clinic [unknown date] [cited 2018 Nov 2]. Available from: https://my.clevelandclinic.org/health/articles/7050-aerobic-exercise
- Ross R, Blair SN, Arena R, Church TS, Després JP, Franklin BA, et al. Importance of assessing cardiorespiratory fitness in clinical practice: a case for fitness as a clinical vital sign. Circulation [Internet]. 2016 Dec [cited 2018 Nov 2];134(24);e653-e699. Available from: https://www.ncbi.nlm.nih.gov/pubmed/27881567 doi: 10.1161/CIR.0000000000000461
- Mandsager K, Harb S, Cremer P, Phelan D, Nissen SE, Jaber W. Association of cardiorespiratory fitness with long-term mortality among adults undergoing exercise treadmill testing. JAMA Netw Open [Internet]. 2018 Oct [cited 2018 Nov 2];1(6):e183605. Available from: https://jamanetwork.com/journals/jamanetworkopen/fullarticle/2707428 doi: 10.1001/jamanetworkopen.2018.3605
- Society for Vascular Surgery. Hyperlipidemia [Internet]. Chicago: Society for Vascular Surgery [unknown date] [cited 2018 Nov 2]. Available from: https://vascular.org/patient-resources/vascular-conditions/hyperlipidemia