When an Exercise Physiologist is referred a patient, weight loss is often one of the specified goals for a client with cardio-metabolic disease. While reducing weight can have a number of positive effects on the body, is it ever specified that the exercise program be sufficient enough to improve cardio respiratory fitness? Often not. Although this is something the Exercise Physiologist needs to consider.
Recent studies have shown that an increase in cardio-respiratory fitness can have major positive effects in improving cardio-metabolic health.
There is strong evidence that an increased Body Mass Index (BMI), especially in regards to abdominal obesity (fatness around the stomach area), is associated with metabolic disease and cardiovascular issues. Though weight alone is normally a poor indicator of whether someone is health or not, especially for those who train with weights. Weight training can increase muscle mass and reduce visceral fat (fat around the organs), resulting in minimal weight change, while it may have significant effect on fitness and decrease the risk of disease. Studies have shown that overall weight may not be the key determinate to decreasing risk of cardiovascular disease. More important is the increase in respiratory fitness and the decrease of visceral fat through cardiovascular exercise and weight training.
An analysis of recent studies have revealed:
- Without weight loss in obese individuals, it is possible to decrease blood pressure to improve health. (King et al 2009)
- Weight loss in obese healthy individuals yields no significant improvement in their longevity. Therefore if weight loss is undertaken without increasing cardio respiratory fitness (CRF), it may yield no benefit for decreasing all cause mortality (ACM) risk in healthy overweight individuals.
- Weight loss in obese ‘unhealthy’ individuals CAN yield a decrease in ACM.
- When comparing a reduction of ACM, when focus is comparing BMI & CRF, it is shown that the group that maintained their CRF over 11 years had a 30% less risk of ACM and 28% less risk of CVD.
- The same study revealed a 40% reduction in ACM and 44% in CVD for those men that increased CRF.
- The group that increased their BMI but also maintained or improved CRF did not increase their ACM risk when compared to self. Although they DID increase their risk of CVD mortality compared to those that decreased BMI. Men who decreased their CRF had an increased risk of ACM and CVD irrespective of BMI change. (Lee et al 2012)
In conclusion the results of these studies show that maintaining or improving CRF results in significant reductions in ACM and CVD mortality. More importantly the study showed that if CRF was maintained or improved any increase in BMI was not statistically significant to risk.
This is not to suggest weight loss should not be prescribed for overweight individuals, it suggests increases in CRF are significantly important to both ACM and CVD mortaility. If weight loss is prescribed it should be completed with goals of increasing CRF in mind as CRF is shown to be most effective in decreasing risk from these studies.
B.App.Sci (Sp&ExSci) ESSAM AEP
- Gillam, I, 2012, Fitness vs Fatness – What has the greatest influence on cardio-respiratory health and longevity, Activate, March 2012 issue 1.
- Lee DC et al, 2011, Long term effects of changes in cardio-respiratory fitness and body mass index on all-cause and cardiovascular disease mortality in men, Circulation 2011, 124:2483-2490
- King NA et al, 2009, Beneficial effects of exercise:shifting focus from body weight to other markers of health, British J. Sports Med. 2009, 43: 924-927