According to certain scientific studies carried out on rats, elderly people suffering from heart problems and with an athletic background in endurance "should curse" too much aerobic activity carried out in the course of their lives.
Athlete's Heart: Health or Illness?
An athlete's heart is characterized by better contractile abilities, both in terms of efficiency and effectiveness. All this thanks to different adaptations: the muscle fibers (which contract to pump blood) are stronger and more elastic, the dimensions of the walls and the heart cavities are greater, the valves open and close better, the overall volume is greater, the coronary blood supply is higher (not by ramifications but by flow), muscle myosin has a greater ATPase activity, etc. Such adaptations translate into functional improvements that enhance the athletic and physical health of the athlete; they are: bradycardia (reduction of heart rate), increase in coronary reserve (response to increase the oxygenation of the heart under stress), increase in peripheral capillarization, venous return and elasticity of the arteries.
We remind you that even sportsmen who practice strength and power activities undergo cardiac changes, but of a different nature. In this case, only a thickening of the ventricular walls occurs, while the internal cavities remain unchanged.
Obviously, neither the first nor the second circumstance should be confused with the primary cardiomyopathies, among which, for example, the dilating (in which the cardiac cavity is abnormally enlarged and creates considerable imbalances) and the hypertrophic (characterized by an abnormal thickening of the heart muscle without an increase in pumping capacity; among these we recall the hypertrophy of the left ventricle, a frequent complication of the use of anabolics for performance purposes).
Despite all these benefits, some increased likelihood of developing arrhythmias has been shown in older cross-country athletes.
Some Cross Country Athletes Have Heart Problems: Why?
Assuming that these are ex-elite athletes, or professionals who exploited immense loads and volumes of aerobic training for competitive purposes (cyclists, marathon runners, etc.), it seems that, having reached old age, some of them suffer from heart dysfunctions.
In light of this suspicion, the researchers certainly did not wait. Endurance exercise: interferes with heart rhythm is the title of an "advertisement on the well-known site" BBC.com "(in the news section), published on 13 May 2014 and based on what was published in" PubMed "in the same period:"Excercise training reduces resting heart rate via downregulation of the funny rods HCN4". The authors are: D" Souza A, Bucchi A, Johnsen AB, Logantha SJ, Monfredi O, Yanni J, Prehar S, Hart G, Cartwright E, Wisloff U, Dobryznski H, DiFrancesco D, Morris GM, Boyett MR; the abstract mentions the following:
"Endurance athletes have sinus bradycardia, that is, a slow heart rate at rest, associated with a higher incidence of sinus node dysfunction (pacemaker) requiring the implantation of an electronic pacemaker in old age. These variations are therefore not attributable to modifications of the autonomic nervous system, but to intrinsic electrophysiological changes of the natural pacemaker. We have shown that induced bradycardia formation persists after blockade of the autonomic nervous system in vivo in mice and in vitro with denervated pacemaker. We also show a widespread restructuring of the pacemaker ion channels, in particular of the HCN4 regulation (protein) and of the corresponding ion current "If". Blockade of "If" abolishes the difference in heart rate in trained and sedentary animals in vivo, and in vitro. We observe a downregulation of Tbx3, an upregulation of NSRF and miR-1 induced by training, which explain the downregulation of the HCN4 protein. These results justify the pathological potential of "cardiac adaptation to" exercise ".
In summary, the "British Heart Foundation"argues that, for these molecular modifications, certain athletes may suffer from heart rhythm disturbances (such as arrhythmias) and require the implantation of a pacemaker. On the other hand, the specialists also specify that: to date, the benefits of aerobic activity outweigh the risks, and much research is still needed to better define the results.
In conclusion, the excess of aerobic activity protracted for decades can be harmful; on the other hand, by respecting a few simple recommendations, aerobic activity is anything but harmful. These are:
- Perform 150 minutes (2 hours and 30 minutes) of aerobic activity per week with moderate intensity (obviously, this totally excludes competitive activities and is contextualized in the health field)
- It is not necessary to have just one or two long sessions; everything else! Better to divide the volume into several smaller sessions
- It is important to respect the recovery times between sessions; over-training can affect (therefore weaken) even the strongest athletes.
- Be sure to "warm up" your muscles and heart before strenuous exercise
- Always perform the appropriate de-fatigue and stretch at the end of the session or in separate sessions.
Reference sites:
- BBC: www.bbc.com/news/healt-27389257
- PUBMED: http://www.ncbi.nlm.nih.gov/pubmed/24825544.
