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  <front>
    <journal-meta>
      <journal-id journal-id-type="nlm-ta">Arq Bras Cardiol</journal-id>
      <journal-id journal-id-type="publisher-id">abc</journal-id>
      <journal-title-group>
        <journal-title>Arquivos Brasileiros de Cardiologia</journal-title>
        <abbrev-journal-title abbrev-type="publisher">Arq. Bras. Cardiol.</abbrev-journal-title>
      </journal-title-group>
      <issn pub-type="ppub">0066-782X</issn>
      <issn pub-type="epub">1678-4170</issn>
      <publisher>
        <publisher-name>Sociedade Brasileira de Cardiologia - SBC</publisher-name>
      </publisher>
    </journal-meta>
    <article-meta>
      <article-id specific-use="scielo-v3" pub-id-type="publisher-id">sLj4tPJpSWfQHpmrpKfgjJP</article-id>
      <article-id specific-use="scielo-v2" pub-id-type="publisher-id">S0066-782X2025000500205</article-id>
      <article-id pub-id-type="doi">10.36660/abc.20250231</article-id>
      <article-id pub-id-type="other">00205</article-id>
      <article-categories>
        <subj-group subj-group-type="heading">
          <subject>Minieditorial</subject>
        </subj-group>
      </article-categories>
      <title-group>
        <article-title>Al&#233;m dos Limites: O que 366 Maratonas Consecutivas Revelam sobre o Cora&#231;&#227;o Humano</article-title>
      </title-group>
      <contrib-group>
        <contrib contrib-type="author">
          <name>
            <surname>Braga</surname>
            <given-names>Fabricio</given-names>
          </name>
          <xref ref-type="aff" rid="aff1">
            <sup>1</sup>
          </xref>
          <xref ref-type="aff" rid="aff2">
            <sup>2</sup>
          </xref>
        </contrib>
        <contrib contrib-type="author">
          <contrib-id contrib-id-type="orcid">0000-0003-2357-5176</contrib-id>
          <name>
            <surname>Stein</surname>
            <given-names>Ricardo</given-names>
          </name>
          <xref ref-type="aff" rid="aff3">
            <sup>3</sup>
          </xref>
          <xref ref-type="aff" rid="aff4">
            <sup>4</sup>
          </xref>
          <xref ref-type="corresp" rid="c1"/>
        </contrib>
        <aff id="aff1">
          <label>1</label>
          <institution content-type="orgname">Laborat&#243;rio de Performance Humana</institution>
          <addr-line>
            <named-content content-type="city">Rio de Janeiro</named-content>
            <named-content content-type="state">RJ</named-content>
          </addr-line>
          <country country="BR">Brasil</country>
          <institution content-type="original">Laborat&#243;rio de Performance Humana, Rio de Janeiro, RJ &#8211; Brasil</institution>
        </aff>
        <aff id="aff2">
          <label>2</label>
          <institution content-type="orgname">Universidade do Estado do Rio de Janeiro</institution>
          <institution content-type="orgdiv1">Departamento de Cardiologia</institution>
          <addr-line>
            <named-content content-type="city">Rio de Janeiro</named-content>
            <named-content content-type="state">RJ</named-content>
          </addr-line>
          <country country="BR">Brasil</country>
          <institution content-type="original">Departamento de Cardiologia, Universidade do Estado do Rio de Janeiro (UERJ), Rio de Janeiro, RJ &#8211; Brasil</institution>
        </aff>
        <aff id="aff3">
          <label>3</label>
          <institution content-type="orgname">Grupo de Pesquisa em Cardiologia do Exerc&#237;cio do Hospital de Cl&#237;nicas de Porto Alegre (CardioEx-HCPA)</institution>
          <addr-line>
            <named-content content-type="city">Porto Alegre</named-content>
            <named-content content-type="state">RS</named-content>
          </addr-line>
          <country country="BR">Brasil</country>
          <institution content-type="original">Grupo de Pesquisa em Cardiologia do Exerc&#237;cio do Hospital de Cl&#237;nicas de Porto Alegre (CardioEx-HCPA), Porto Alegre, RS &#8211; Brasil</institution>
        </aff>
        <aff id="aff4">
          <label>4</label>
          <institution content-type="orgname">Universidade Federal do Rio Grande do Sul</institution>
          <addr-line>
            <named-content content-type="city">Porto Alegre</named-content>
            <named-content content-type="state">RS</named-content>
          </addr-line>
          <country country="BR">Brasil</country>
          <institution content-type="original">Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS &#8211; Brasil</institution>
        </aff>
      </contrib-group>
      <author-notes>
        <corresp id="c1"><label>Correspond&#234;ncia:</label><bold>Ricardo Stein &#8226;</bold> Universidade Federal do Rio Grande do Sul &#8211; Rua Ramiro Barcelos, 2350. CEP <postal-code>90035-903</postal-code>, Servi&#231;o de Fisiatria/T&#233;rreo, Porto Alegre, RS &#8211; Brasil E-mail: <email>kuqui.r@gmail.com</email></corresp>
      </author-notes>
      <pub-date date-type="pub" publication-format="electronic">
        <day>04</day>
        <month>07</month>
        <year>2025</year>
      </pub-date>
      <pub-date publication-format="electronic" date-type="collection">
        <year>2025</year>
      </pub-date>
      <volume>122</volume>
      <issue>05</issue>
      <elocation-id>e20250231</elocation-id>
      <history>
        <date date-type="received">
          <day>02</day>
          <month>04</month>
          <year>2025</year>
        </date>
        <date date-type="rev-recd">
          <day>14</day>
          <month>04</month>
          <year>2025</year>
        </date>
        <date date-type="accepted">
          <day>14</day>
          <month>04</month>
          <year>2025</year>
        </date>
      </history>
      <permissions>
        <license license-type="open-access" xml:lang="en" xlink:href="https://creativecommons.org/licenses/by/4.0/">
          <license-p>This is an open-access article distributed under the terms of the Creative Commons Attribution License</license-p>
        </license>
      </permissions>
      <kwd-group xml:lang="pt">
        <title>Palavras-chave</title>
        <kwd>Corrida</kwd>
        <kwd>Maratona</kwd>
        <kwd>Cora&#231;&#227;o do Atleta</kwd>
        <kwd>Exerc&#237;cio Intenso</kwd>
        <kwd>Limites</kwd>
      </kwd-group>
      <counts>
        <fig-count count="0"/>
        <table-count count="0"/>
        <equation-count count="0"/>
        <ref-count count="8"/>
      </counts>
    </article-meta>
  </front>
  <body>
    <disp-quote>
      <p>
        <bold>"O corpo humano &#233; capaz de adapta&#231;&#245;es incr&#237;veis &#8212; se lhe for dada a chance."</bold>
      </p>
      <p>&#8212; <italic>Michael Joyner, fisiologista da Mayo Clinic e uma autoridade em desempenho de resist&#234;ncia</italic></p>
    </disp-quote>
    <p>A cultura ocidental sempre celebrou a busca por extremos f&#237;sicos &#8212; desde feito &#233;picos antigos at&#233; ultramaratonas modernas, atividades que envolvem a resist&#234;ncia sempre foi mais do que esporte: &#233; narrativa, identidade e desafio aos limites percebidos. Completar uma &#250;nica maratona j&#225; coloca um estresse substancial nos sistemas cardiovascular, metab&#243;lico e musculoesquel&#233;tico. Correr uma maratona 366 vezes em 366 dias consecutivos muda o foco da fisiologia para a filosofia: At&#233; onde o cora&#231;&#227;o humano pode realmente ir?</p>
    <p>O estudo de caso publicado nesta edi&#231;&#227;o dos Arquivos Brasileiros de Cardiologia<sup><xref ref-type="bibr" rid="B1">1</xref></sup> documenta um feito anteriormente inimagin&#225;vel: um atleta amador brasileiro completou uma maratona completa todos os dias durante um ano &#8212; tudo sob supervis&#227;o m&#233;dica sistem&#225;tica. Mais que um Recorde Mundial do <italic>Guinness</italic>, isso &#233; uma explora&#231;&#227;o em tempo real da adaptabilidade humana. O sistema cardiovascular do atleta permaneceu notavelmente est&#225;vel ao longo do ano, com o consumo m&#225;ximo de oxig&#234;nio (VO<sub>2</sub> max), estrutura card&#237;aca e biomarcadores dentro de faixas fisiol&#243;gicas, apesar do volume extremo de exerc&#237;cio.</p>
    <p>Esse fen&#244;meno se alinha com uma tend&#234;ncia mais ampla de recordes em provas de alta resist&#234;ncia que combinam desempenho com persist&#234;ncia. Desde os "50 <italic>Ironmans</italic> em 50 dias" at&#233; a corrida recorde de M&#225;rcio Villar de sete dias consecutivos na esteira<sup><xref ref-type="bibr" rid="B2">2</xref></sup> &#8212; outro brasileiro listado no <italic>Guinness Book of Records</italic> &#8212; o mundo da resist&#234;ncia continua a reescrever seus pr&#243;prios limites. Feitos como esse exigem foco inabal&#225;vel, resili&#234;ncia extrema e resist&#234;ncia mental quase sobre-humana. Eles tamb&#233;m oferecem aos cardiologistas e cientistas do esporte oportunidades raras de observar a adapta&#231;&#227;o cr&#244;nica de alt&#237;ssima carga <italic>in vivo.</italic><sup><xref ref-type="bibr" rid="B3">3</xref>,<xref ref-type="bibr" rid="B4">4</xref></sup></p>
    <p>As adapta&#231;&#245;es fisiol&#243;gicas &#224; resist&#234;ncia prolongada incluem aumento do volume card&#237;aco, melhora da fun&#231;&#227;o endotelial e aumento do VO<sub>2</sub> max. No entanto, estudos anteriores tamb&#233;m sugeriram que o exerc&#237;cio de resist&#234;ncia excessivo pode estar associado &#224; remodela&#231;&#227;o estrutural e maior incid&#234;ncia de arritmias ou calcifica&#231;&#227;o das art&#233;rias coron&#225;rias.<sup><xref ref-type="bibr" rid="B5">5</xref>,<xref ref-type="bibr" rid="B6">6</xref></sup> Neste caso, a aus&#234;ncia de remodela&#231;&#227;o adversa, apesar da carga sem precedentes, levanta quest&#245;es cr&#237;ticas: a intensidade foi protetora? O suporte psicol&#243;gico e nutricional foi essencial para prevenir a m&#225; adapta&#231;&#227;o?</p>
    <p>O atleta treinou e competiu pr&#243;ximo ao seu primeiro limiar ventilat&#243;rio, uma estrat&#233;gia que pode ter mitigado o potencial de les&#227;o mioc&#225;rdica. Testes cardiopulmonares, ecocardiogramas e biomarcadores sangu&#237;neos seriados revelaram um quadro de estabilidade. O cora&#231;&#227;o do atleta, literalmente, resistiu.</p>
    <p>No entanto, isso &#233; mais que um triunfo fisiol&#243;gico. &#201; uma aula de prepara&#231;&#227;o, apoio e variabilidade humana. Atletas de resist&#234;ncia de elite continuam a desafiar limites te&#243;ricos de desempenho &#8212; alguns modelos preveem um tempo de maratona de 1:57:58 como fisiologicamente poss&#237;vel.<sup><xref ref-type="bibr" rid="B4">4</xref></sup> Da mesma forma, feitos como o descrito aqui nos for&#231;am a reconsiderar onde o risco come&#231;a e termina. O limite entre adapta&#231;&#227;o e dano n&#227;o &#233; universal &#8212; &#233; profundamente individual.</p>
    <p>Existe tamb&#233;m um toque po&#233;tico nesta hist&#243;ria. Muito similar a S&#237;sifo, condenado a empurrar uma enorme pedra at&#233; o topo de uma montanha. Por&#233;m, toda vez que ele estava prestes a alcan&#231;ar o cume, a pedra rolava de volta para baixo. No caso do maratonista em quest&#227;o, este atleta enfrentou a mesma dist&#226;ncia, dia ap&#243;s dia. Mas, ao contr&#225;rio de S&#237;sifo, ele escolheu este caminho &#8212; cada passo carregava sua pr&#243;pria li&#231;&#227;o. A monotonia tornou-se um m&#233;todo. A repeti&#231;&#227;o, uma revela&#231;&#227;o. Em uma sociedade cada vez mais obcecada pelo imediatismo e atalhos, a consist&#234;ncia em longo prazo pode ser a forma final de rebeli&#227;o.</p>
    <p>Este editorial tamb&#233;m levanta uma implica&#231;&#227;o cient&#237;fica essencial: estudos como este n&#227;o devem ser vistos como glorifica&#231;&#227;o do excesso, e sim como explora&#231;&#227;o do limite da sa&#250;de humana. Esfor&#231;os de alta resist&#234;ncia exigem cuidados multidisciplinares &#8212; cardiologistas, fisiologistas, nutricionistas, psic&#243;logos. Tais cuidados tamb&#233;m deixam claras as limita&#231;&#245;es da estratifica&#231;&#227;o de risco baseada em popula&#231;&#245;es quando aplicada &#224; fisiologia altamente individualizada.</p>
    <p>Do ponto de vista cl&#237;nico, este caso refor&#231;a o papel da triagem cardiovascular cuidadosa e do acompanhamento seriado em atletas que tentam desafios extremos. Lembra-nos que os limites fisiol&#243;gicos n&#227;o s&#227;o limiares fixos, mas zonas flex&#237;veis, moldadas pelo contexto, prepara&#231;&#227;o e biologia.<sup><xref ref-type="bibr" rid="B7">7</xref>,<xref ref-type="bibr" rid="B8">8</xref></sup></p>
    <p>Finalmente, isso &#233; um chamado para reformular a narrativa acerca do exerc&#237;cio. Embora a atividade f&#237;sica moderada continue sendo a base da sa&#250;de p&#250;blica, hist&#243;rias como essa nos desafiam a fazer melhores perguntas, desenhar estudos mais inteligentes e respeitar a varia&#231;&#227;o individual. O excesso em um corpo pode ser adapta&#231;&#227;o em outro.</p>
    <p>Os limites do corpo humano n&#227;o s&#227;o desenhados em livros did&#225;ticos. Eles s&#227;o descobertos &#8212; &#224;s vezes uma maratona de cada vez.</p>
    <p>Este estudo nos lembra: a resist&#234;ncia n&#227;o &#233; apenas sobre tempo ou dist&#226;ncia. &#201; sobre explorar onde o corpo se dobra, e onde &#8212; apenas talvez &#8212; ele n&#227;o se quebra.</p>
  </body>
  <back>
    <fn-group>
      <fn fn-type="other" id="fn1">
        <label>Minieditorial referente ao artigo:</label>
        <p>Recorde de Resist&#234;ncia em 366 Maratonas durante 366 Dias: Um Estudo de Caso</p>
      </fn>
    </fn-group>
    <ref-list>
      <title>Refer&#234;ncias</title>
      <ref id="B1">
        <label>1</label>
        <element-citation publication-type="journal">
          <person-group person-group-type="author">
            <name>
              <surname>Souza</surname>
              <given-names>FR</given-names>
            </name>
            <name>
              <surname>Lopes</surname>
              <given-names>RD</given-names>
            </name>
            <name>
              <surname>Fonseca</surname>
              <given-names>GWP</given-names>
            </name>
            <name>
              <surname>Barretto</surname>
              <given-names>RBM</given-names>
            </name>
            <name>
              <surname>Battaglia</surname>
              <given-names>AC</given-names>
              <suffix>Filho</suffix>
            </name>
            <name>
              <surname>do Val</surname>
              <given-names>RM</given-names>
            </name>
            <etal/>
          </person-group>
          <article-title>Record-Breaking Endurance of 366 Marathons in 366 Days: A Case Study</article-title>
          <source>Arq Bras Cardiol</source>
          <year>2025</year>
          <volume>122</volume>
          <issue>5</issue>
          <elocation-id>e20240838</elocation-id>
          <comment>
            <ext-link ext-link-type="uri" xlink:href="https://doi.org/10.36660/abc.20240838">https://doi.org/10.36660/abc.20240838</ext-link>
          </comment>
        </element-citation>
        <mixed-citation>1 Souza FR, Lopes RD, Fonseca GWP, Barretto RBM, Battaglia Filho AC, do Val RM, et al. Record-Breaking Endurance of 366 Marathons in 366 Days: A Case Study. Arq Bras Cardiol. 2025; 122(5):e20240838. DOI: <ext-link ext-link-type="uri" xlink:href="https://doi.org/10.36660/abc.20240838">https://doi.org/10.36660/abc.20240838</ext-link>.</mixed-citation>
      </ref>
      <ref id="B2">
        <label>2</label>
        <element-citation publication-type="book">
          <person-group person-group-type="author">
            <name>
              <surname>Villar</surname>
              <given-names>M</given-names>
            </name>
          </person-group>
          <chapter-title>Atleta Brasileiro det&#233;m Recorde Mundial de Maior Dist&#226;ncia Percorrida em Esteira em 7 dias</chapter-title>
          <source>Reconhecido pelo Guinness World Records [Internet]</source>
          <publisher-loc>S&#227;o Paulo</publisher-loc>
          <publisher-name>Ativo.com</publisher-name>
          <year>2016</year>
          <date-in-citation content-type="access-date">cited 2025 May 9</date-in-citation>
          <comment>Available from: <ext-link ext-link-type="uri" xlink:href="https://www.ativo.com/corrida-de-rua/marcio-villar-supera-recorde-mundial-na-esteira/">https://www.ativo.com/corrida-de-rua/marcio-villar-supera-recorde-mundial-na-esteira/</ext-link></comment>
        </element-citation>
        <mixed-citation>2 Villar M. Atleta Brasileiro det&#233;m Recorde Mundial de Maior Dist&#226;ncia Percorrida em Esteira em 7 dias. Reconhecido pelo Guinness World Records [Internet]. S&#227;o Paulo: Ativo.com; 2016 [cited 2025 May 9]. Available from: <ext-link ext-link-type="uri" xlink:href="https://www.ativo.com/corrida-de-rua/marcio-villar-supera-recorde-mundial-na-esteira/">https://www.ativo.com/corrida-de-rua/marcio-villar-supera-recorde-mundial-na-esteira/</ext-link>.</mixed-citation>
      </ref>
      <ref id="B3">
        <label>3</label>
        <element-citation publication-type="journal">
          <person-group person-group-type="author">
            <name>
              <surname>Joyner</surname>
              <given-names>MJ</given-names>
            </name>
          </person-group>
          <article-title>Modeling: Optimal Marathon Performance on the Basis of Physiological Factors</article-title>
          <source>J Appl Physiol</source>
          <year>1991</year>
          <volume>70</volume>
          <issue>2</issue>
          <fpage>683</fpage>
          <lpage>687</lpage>
          <pub-id pub-id-type="doi">10.1152/jappl.1991.70.2.683</pub-id>
        </element-citation>
        <mixed-citation>3 Joyner MJ. Modeling: Optimal Marathon Performance on the Basis of Physiological Factors. J Appl Physiol. 1991;70(2):683-7. doi: 10.1152/jappl.1991.70.2.683.</mixed-citation>
      </ref>
      <ref id="B4">
        <label>4</label>
        <element-citation publication-type="journal">
          <person-group person-group-type="author">
            <name>
              <surname>Sutthimat</surname>
              <given-names>P</given-names>
            </name>
            <name>
              <surname>Mekchay</surname>
              <given-names>K</given-names>
            </name>
          </person-group>
          <article-title>Closed-form Formulas for Conditional Moments of Inhomogeneous Pearson Diffusion Processes</article-title>
          <source>Commun Nonlinear Sci Numer Simul</source>
          <year>2022</year>
          <volume>106</volume>
          <fpage>106095</fpage>
          <lpage>106095</lpage>
          <pub-id pub-id-type="doi">10.1016/j.cnsns.2021.106095</pub-id>
        </element-citation>
        <mixed-citation>4 Sutthimat P, Mekchay K. Closed-form Formulas for Conditional Moments of Inhomogeneous Pearson Diffusion Processes. Commun Nonlinear Sci Numer Simul. 2022;106:106095. doi: 10.1016/j.cnsns.2021.106095.</mixed-citation>
      </ref>
      <ref id="B5">
        <label>5</label>
        <element-citation publication-type="journal">
          <person-group person-group-type="author">
            <name>
              <surname>La Gerche</surname>
              <given-names>A</given-names>
            </name>
            <name>
              <surname>Burns</surname>
              <given-names>AT</given-names>
            </name>
            <name>
              <surname>Mooney</surname>
              <given-names>DJ</given-names>
            </name>
            <name>
              <surname>Inder</surname>
              <given-names>WJ</given-names>
            </name>
            <name>
              <surname>Taylor</surname>
              <given-names>AJ</given-names>
            </name>
            <name>
              <surname>Bogaert</surname>
              <given-names>J</given-names>
            </name>
            <etal/>
          </person-group>
          <article-title>Exercise-Induced Right Ventricular Dysfunction and Structural Remodelling in Endurance Athletes</article-title>
          <source>Eur Heart J</source>
          <year>2012</year>
          <volume>33</volume>
          <issue>8</issue>
          <fpage>998</fpage>
          <lpage>1006</lpage>
          <pub-id pub-id-type="doi">10.1093/eurheartj/ehr397</pub-id>
        </element-citation>
        <mixed-citation>5 La Gerche A, Burns AT, Mooney DJ, Inder WJ, Taylor AJ, Bogaert J, et al. Exercise-Induced Right Ventricular Dysfunction and Structural Remodelling in Endurance Athletes. Eur Heart J. 2012;33(8):998-1006. doi: 10.1093/eurheartj/ehr397.</mixed-citation>
      </ref>
      <ref id="B6">
        <label>6</label>
        <element-citation publication-type="journal">
          <person-group person-group-type="author">
            <name>
              <surname>O&#8217;Keefe</surname>
              <given-names>JH</given-names>
            </name>
            <name>
              <surname>Patil</surname>
              <given-names>HR</given-names>
            </name>
            <name>
              <surname>Lavie</surname>
              <given-names>CJ</given-names>
            </name>
            <name>
              <surname>Magalski</surname>
              <given-names>A</given-names>
            </name>
            <name>
              <surname>Vogel</surname>
              <given-names>RA</given-names>
            </name>
            <name>
              <surname>McCullough</surname>
              <given-names>PA</given-names>
            </name>
          </person-group>
          <article-title>Potential Adverse Cardiovascular Effects from Excessive Endurance Exercise</article-title>
          <source>Mayo Clin Proc</source>
          <year>2012</year>
          <volume>87</volume>
          <issue>6</issue>
          <fpage>587</fpage>
          <lpage>595</lpage>
          <pub-id pub-id-type="doi">10.1016/j.mayocp.2012.04.005</pub-id>
        </element-citation>
        <mixed-citation>6 O&#8217;Keefe JH, Patil HR, Lavie CJ, Magalski A, Vogel RA, McCullough PA. Potential Adverse Cardiovascular Effects from Excessive Endurance Exercise. Mayo Clin Proc. 2012;87(6):587-95. doi: 10.1016/j.mayocp.2012.04.005.</mixed-citation>
      </ref>
      <ref id="B7">
        <label>7</label>
        <element-citation publication-type="journal">
          <person-group person-group-type="author">
            <name>
              <surname>Rossello</surname>
              <given-names>X</given-names>
            </name>
            <name>
              <surname>Ramallal</surname>
              <given-names>R</given-names>
            </name>
            <name>
              <surname>Romaguera</surname>
              <given-names>D</given-names>
            </name>
            <name>
              <surname>Alonso-G&#243;mez</surname>
              <given-names>AM</given-names>
            </name>
            <name>
              <surname>Alonso</surname>
              <given-names>A</given-names>
            </name>
            <name>
              <surname>Tojal-Sierra</surname>
              <given-names>L</given-names>
            </name>
            <etal/>
          </person-group>
          <article-title>Effect of an Intensive Lifestyle Intervention on the Structural and Functional Substrate for Atrial Fibrillation in People with Metabolic Syndrome</article-title>
          <source>Eur J Prev Cardiol</source>
          <year>2024</year>
          <volume>31</volume>
          <fpage>629</fpage>
          <lpage>639</lpage>
          <pub-id pub-id-type="doi">10.1093/eurjpc/zwad380</pub-id>
        </element-citation>
        <mixed-citation>7 Rossello X, Ramallal R, Romaguera D, Alonso-G&#243;mez AM, Alonso A, Tojal-Sierra L, et al. Effect of an Intensive Lifestyle Intervention on the Structural and Functional Substrate for Atrial Fibrillation in People with Metabolic Syndrome. Eur J Prev Cardiol. 2024;31:629-39. doi: 10.1093/eurjpc/zwad380.</mixed-citation>
      </ref>
      <ref id="B8">
        <label>8</label>
        <element-citation publication-type="journal">
          <person-group person-group-type="author">
            <name>
              <surname>Maron</surname>
              <given-names>BJ</given-names>
            </name>
            <name>
              <surname>Pelliccia</surname>
              <given-names>A</given-names>
            </name>
          </person-group>
          <article-title>The Heart of Trained Athletes: Cardiac Remodeling and the Risks of Sports, Including Sudden Death</article-title>
          <source>Circulation</source>
          <year>2006</year>
          <volume>114</volume>
          <issue>15</issue>
          <fpage>1633</fpage>
          <lpage>1644</lpage>
          <pub-id pub-id-type="doi">10.1161/CIRCULATIONAHA.106.613562</pub-id>
        </element-citation>
        <mixed-citation>8 Maron BJ, Pelliccia A. The Heart of Trained Athletes: Cardiac Remodeling and the Risks of Sports, Including Sudden Death. Circulation. 2006;114(15):1633-44. doi: 10.1161/CIRCULATIONAHA.106.613562.</mixed-citation>
      </ref>
    </ref-list>
  </back>
  <sub-article article-type="translation" id="S1" xml:lang="en">
    <front-stub>
      <article-id pub-id-type="doi">10.36660/abc.20250231i</article-id>
      <article-categories>
        <subj-group subj-group-type="heading">
          <subject>Short Editorial</subject>
        </subj-group>
      </article-categories>
      <title-group>
        <article-title>Beyond Limits: What 366 Consecutive Marathons Reveal about the Human Heart</article-title>
      </title-group>
      <contrib-group>
        <contrib contrib-type="author">
          <name>
            <surname>Braga</surname>
            <given-names>Fabricio</given-names>
          </name>
          <xref ref-type="aff" rid="aff5">
            <sup>1</sup>
          </xref>
          <xref ref-type="aff" rid="aff6">
            <sup>2</sup>
          </xref>
        </contrib>
        <contrib contrib-type="author">
          <contrib-id contrib-id-type="orcid">0000-0003-2357-5176</contrib-id>
          <name>
            <surname>Stein</surname>
            <given-names>Ricardo</given-names>
          </name>
          <xref ref-type="aff" rid="aff7">
            <sup>3</sup>
          </xref>
          <xref ref-type="aff" rid="aff8">
            <sup>4</sup>
          </xref>
          <xref ref-type="corresp" rid="c2"/>
        </contrib>
        <aff id="aff5">
          <label>1</label>
          <addr-line>
            <named-content content-type="city">Rio de Janeiro</named-content>
            <named-content content-type="state">RJ</named-content>
          </addr-line>
          <country country="BR">Brazil</country>
          <institution content-type="original">Laborat&#243;rio de Performance Humana, Rio de Janeiro, RJ &#8211; Brazil</institution>
        </aff>
        <aff id="aff6">
          <label>2</label>
          <addr-line>
            <named-content content-type="city">Rio de Janeiro</named-content>
            <named-content content-type="state">RJ</named-content>
          </addr-line>
          <country country="BR">Brazil</country>
          <institution content-type="original">Departamento de Cardiologia, Universidade do Estado do Rio de Janeiro (UERJ), Rio de Janeiro, RJ &#8211; Brazil</institution>
        </aff>
        <aff id="aff7">
          <label>3</label>
          <addr-line>
            <named-content content-type="city">Porto Alegre</named-content>
            <named-content content-type="state">RS</named-content>
          </addr-line>
          <country country="BR">Brazil</country>
          <institution content-type="original">Grupo de Pesquisa em Cardiologia do Exerc&#237;cio do Hospital de Cl&#237;nicas de Porto Alegre (CardioEx-HCPA), Porto Alegre, RS &#8211; Brazil</institution>
        </aff>
        <aff id="aff8">
          <label>4</label>
          <addr-line>
            <named-content content-type="city">Porto Alegre</named-content>
            <named-content content-type="state">RS</named-content>
          </addr-line>
          <country country="BR">Brazil</country>
          <institution content-type="original">Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS &#8211; Brazil</institution>
        </aff>
      </contrib-group>
      <author-notes>
        <corresp id="c2"><label>Mailing Address:</label><bold>Ricardo Stein &#8226;</bold> Universidade Federal do Rio Grande do Sul &#8211; Rua Ramiro Barcelos, 2350. Postal Code <postal-code>90035-903</postal-code>, Servi&#231;o de Fisiatria/T&#233;rreo, Porto Alegre, RS &#8211; Brazil E-mail: <email>kuqui.r@gmail.com</email></corresp>
      </author-notes>
      <kwd-group xml:lang="en">
        <title>Keywords</title>
        <kwd>Running</kwd>
        <kwd>Marathon</kwd>
        <kwd>Athlete's Heart</kwd>
        <kwd>Intense Exercise</kwd>
        <kwd>Limits</kwd>
      </kwd-group>
    </front-stub>
    <body>
      <disp-quote>
        <p>
          <bold>"The human body is capable of amazing adaptations &#8212; if given the chance."</bold>
        </p>
        <p>&#8212; <italic>Michael Joyner, physiologist at the Mayo Clinic and a global authority on endurance performance</italic></p>
      </disp-quote>
      <p>Western culture has always celebrated the pursuit of physical extremes &#8212; from ancient epics to modern ultramarathons, endurance has always been more than sport: it is narrative, identity, and defiance of perceived limits. Completing a single marathon already places substantial stress on the cardiovascular, metabolic, and musculoskeletal systems. Doing a Marathon 366 times over 366 consecutive days shifts the focus from physiology to philosophy: Just how far can the human heart truly go?</p>
      <p>The case study published in this issue of <italic>Arquivos Brasileiros de Cardiologia</italic><sup><xref ref-type="bibr" rid="B1">1</xref></sup> documents a feat previously unimaginable: a Brazilian amateur athlete completed a full marathon every single day for a year &#8212; all under systematic medical supervision. More than a Guinness World Record, this is a real-time exploration of human adaptability. The athlete's cardiovascular system remained remarkably stable throughout the year, with maximal oxygen uptake (VO<sub>2</sub> max), cardiac structure, and biomarkers within physiological ranges, despite the extreme exercise volume.</p>
      <p>This phenomenon aligns with a broader trend of ultra-endurance records that blend performance with persistence. From the "50 Ironman's in 50 days" to M&#225;rcio Villar's record-breaking run of seven consecutive days on a treadmill<sup><xref ref-type="bibr" rid="B2">2</xref></sup> &#8212; another Brazilian listed in the <italic>Guinness Book of Records</italic> &#8212; the endurance world continues to rewrite its own limits. Feats like this demand unbreakable focus, fierce resilience, and near-superhuman mental endurance. They also offer cardiologists and sports scientists rare opportunities to observe chronic, high-load adaptation <italic>in vivo</italic>.<sup><xref ref-type="bibr" rid="B3">3</xref>,<xref ref-type="bibr" rid="B4">4</xref></sup></p>
      <p>Physiological adaptations to prolonged endurance include increased cardiac volume, improved endothelial function, and enhanced VO<sub>2</sub> max. However, previous studies have also suggested that excessive endurance exercise may be associated with structural remodeling and higher incidence of arrhythmias or coronary artery calcification.<sup><xref ref-type="bibr" rid="B5">5</xref>,<xref ref-type="bibr" rid="B6">6</xref></sup> In this case, the absence of adverse remodeling despite the unprecedented load raises critical questions: was the intensity protective? Was psychological and nutritional support essential in preventing maladaptation?</p>
      <p>The athlete trained and competed close to his first ventilatory threshold, a strategy that may have mitigated the potential for myocardial injury. Serial cardiopulmonary tests, echocardiograms, and blood biomarkers revealed a picture of stability. The athlete's heart, quite literally, endured.</p>
      <p>Yet this is more than a physiological triumph. It is a lesson in preparation, support, and human variability. Elite endurance athletes continue to challenge theoretical performance limits &#8212; some models predict a marathon time of 1:57:58 as physiologically possible.<sup><xref ref-type="bibr" rid="B4">4</xref></sup> Similarly, feats like the one described here force us to reconsider where risk begins and ends. The boundary between adaptation and damage is not universal &#8212; it is deeply individual.</p>
      <p>There's also cultural poetry in this story. Much like Sisyphus, condemned to push a huge rock up to the top of a mountain. Yet, every time he was about to reach the summit, the rock would roll back down. In the case of the marathon runner in question, this athlete faced the same distance, day after day. But unlike Sisyphus, he chose this path &#8212; every step carried its own lesson. Monotony became a method. The repetition, a revelation. In a society increasingly obsessed with immediacy and shortcuts, long-term consistency may be the ultimate form of rebellion.</p>
      <p>This editorial also raises an essential scientific implication: studies like this should not be seen as glorifying excess, but rather as exploring the outer envelope of human health. Ultra-endurance efforts demand multidisciplinary care &#8212; cardiologists, physiologists, nutritionists, psychologists. They also highlight the limitations of population-based risk stratification when applied to highly individualized physiology.</p>
      <p>From a clinical perspective, this case reinforces the role of careful cardiovascular screening and serial follow-up in athletes attempting extreme challenges. It reminds us that physiological limits are not fixed thresholds but flexible zones, shaped by context, preparation, and biology.<sup><xref ref-type="bibr" rid="B7">7</xref>,<xref ref-type="bibr" rid="B8">8</xref></sup></p>
      <p>Finally, this is a call to reframe the narrative around exercise. While moderate physical activity remains the foundation of public health, stories like this challenge us to ask better questions, design smarter studies, and respect individual variation. Excess in one body may be adaptation to another.</p>
      <p>The limits of the human body are not drawn in textbooks. They are discovered &#8212; sometimes one marathon at a time.</p>
      <p>This study reminds us: endurance is not just about time or distance. It is about exploring where the body bends, and where &#8212; just maybe &#8212; it does not break.</p>
    </body>
    <back>
      <fn-group>
        <fn fn-type="other" id="fn2">
          <label>Short Editorial related to the article:</label>
          <p>Record-Breaking Endurance of 366 Marathons in 366 Days: A Case Study</p>
        </fn>
      </fn-group>
    </back>
  </sub-article>
</article>
