Is Endurance Exercise Safe? The Myth of Pheidippides

Systemic Responses Towards Oxy-Inflammation, Hormones, and Mood in Breast Cancer Survivors: Preliminary Evidences from Dragon Boat Endurance Race

Background/Objectives: Endurance exercise increases oxygen demand and, when not balanced by antioxidant defenses, consequently, oxidative stress and inflammatory cytokines increase too. In breast cancer survivors (BCS), post-treatment, physical capacity decreases, lowering life quality. Dragon boat (DB) paddling has shown benefits in reducing lymphedema and improving psychological well-being. This study aimed at non-invasively investigating in BCS, by means of saliva and urine samples, the systemic responses to oxy-inflammation, and appetite hormones after a DB endurance race. Methods: 15 BCS and 15 healthy women (5 (CTR) who performed the DB race too) were studied. BCS and CTR were monitored pre- and post-race. Reactive oxygen species (ROS) production, total antioxidant capacity (TAC), lipid peroxidation (8-iso), DNA oxidation (8-OH-dG), nitric oxide metabolites (NOx), inflammation markers (IL-6-10 and TNFα), appetite hormones, electrolytes concentration, psychometric, and physical scales were assessed. Results: At rest, compared to healthy women, BCS showed a significant increase in oxy-inflammation biomarkers. BCS showed a general increase in oxy-inflammation parameters compared to CTR after the DB race. In BCS, there were the following results: ROS: +80%; lipid peroxidation: +103%; DNA oxidation: +44%; interleukins-6: +179%; IL-10: +55%; TNFα: +9%, NOx: +60% increases and unbalanced appetite hormones: leptin (-32%); and ghrelin (+53%). Moreover, the dragon boat offered a holistic approach to recovery, addressing emotional and social needs supporting belonging, love, and esteem needs, reported to be about 56% of the motivations in this activity, while post-race the following increased: a sense of fatigue (+55%); tiredness (48%); a cold sensation (+15%); and +32% pain. Conclusions: This study provided evidence that, in BCS, a DB endurance race produces an important imbalance in the oxy-inflammation state, at the same time being accompanied by a positive impact on subjective mood and general wellness. Future studies should focus on long-term effects.

Does long-term exposure to air pollution suppress parasympathetic reactivation after incremental exercise among healthy males and females?

PURPOSE

As consequences of industrial processes, air pollution has led to increased cardiovascular diseases resulting in mortality. However, there are few pieces of evidence expressing physical fitness and gender impacts in such environments. Regarding long-term exposure to air pollution, this study aimed to determine the effect of physical fitness on post-exercise cardiac parasympathetic reactivation among healthy males and females.

METHODS

120 individuals (46 ± 5 years) participated and were categorized into two main groups (n = 60; EG, CG); (1) The experimental group included individuals living in an air-polluted environment; (2) The control group included the citizens of a clean air region; and two physical fitness status subgroups (n = 30; active vs. sedentary) across both sexes. The heart rate (HR) changes at different timing after performing an incremental exercise, and T30 were calculated as metrics of cardiac parasympathetic reactivation.

RESULTS

The heart rate recovery values were substantially lower in EG in comparison to CG (p < 0.001) at different timing, while, T30 was significantly greater in residents of the air-polluted city compared to CG (p < 0.001). As for heart rate recovery at the 5th minute, the values were significantly lower in the steady-female group in comparison to the active females living in the air-polluted city (p < 0.01).

CONCLUSION

Based on our findings, although physical fitness modifies the adverse impacts of long-term exposure to air pollution on post-exercise cardio-parasympathetic reactivation, it appears to parallel the acute/intermediate recovery of the thermoregulatory and vascular systems, among both sexes, it does not prevent them.

The effects of a 50 km ultramarathon race on high sensitivity cardiac troponin I and NT-proBNP in highly trained athletes

BACKGROUND

High sensitivity cardiac troponins I (hs-cTnI) and T (hs-cTnT) and natriuretic peptides (BNP and NT-proBNP) are universally recognized as cardiac reference biomarkers in patients with acute coronary syndromes and heart failure respectively. However, while on one hand the high sensitivity methods of cardiac biomarkers have provided answers to fundamental pathophysiological and clinical questions in patients with heart disease, less information is available on their assessment in paraphysiological conditions, such as high intensity exercise in healthy athletes. The aim of this study was to evaluate hs-cTnI and NT-proBNP in highly trained runners after a 50 km ultramarathon.

METHODS

We have enrolled 20 highly trained male athletes who have run a 50 km ultramarathon. Blood samples were collected 2 hours before the start of the race (T0) and 20 minutes after the end of the race (T1). The blood concentrations of hs-cTnI and NT-proBNP measured before the race were within reference intervals in all runners.

RESULTS

Hs-cTnI significantly increased after the end of the race (median: 19 ng/L [IQR: 12.5-25.75] versus 6 ng/L [IQR: 4.25-8.0]; P<0.001), in three cases over the upper reference limit (URL) of 34 ng/L. NT-proBNP also significantly increased (median: 78 ng/L [IQR: 68.25-87.75] versus 22 ng/L [IQR: 18.25-26.75]; P<0.001). Three other athletes reached concentration over the URL (125 ng/L).

CONCLUSIONS

Our study showed a significant increase in hs-cTnI and NT-proBNP in highly trained athletes after a 50 km ultramarathon race, and 30% of runners had the values of cardiac biomarkers above URL. More studies with a larger number of athletes will be needed to better understand the effects of intense exercise on the heart of trained athletes.