Disserta??o de Mestrado apresentada para obten??o do grau de Mestre em Atividades de Fitness, na Escola Superior de Desporto e Lazer do Instituto Polit?cnico de Viana do Castelo. Objetivo: analisar os efeitos de um programa de 6 meses de blue exercise baseado no surfing na composi??o corporal, aptid?o cardiorrespirat?ria, n?veis de for?a, equil?brio e qualidade de vida em idosos. M?todos: uma amostra por conveni?ncia foi composta por 37 participantes (24 mulheres), com m?dia de idades de 71,9?3,8 anos, divididos em grupo blue exercise (n=12), grupo controlo (n= 13) ou grupo de participantes que realizavam exerc?cio f?sico da oferta Municipal (EFOM) foi inclu?do no presente estudo (n=12). Os grupos foram avaliados atrav?s de: i) balan?a de bioimped?ncia; ii) 6 min a andar; iii) sentar e levantar durante 30 seg; iv) 8 Feet Up and Go (TUG) e v) escala de bem-estar Warwick-Edinburgh Mental Wellbeing Scale (WEMWS). As avalia??es foram realizadas antes (avalia??o inicial) e ap?s 3 e 6 meses do programa blue exercise que incluiu sess?es de bodyboard, caminhadas e treino de capacidade funcional. O teste n?o param?trico Mann-Whitney U foi utilizado para analisar as diferen?as entre grupos. O teste n?o param?trico Wilcoxon signed-rank foi utilizado para analisar as diferen?as estat?sticas entre os diferentes momentos de avalia??o (inicial vs. 3 meses; inicial vs.6 meses; 3 meses vs.6 meses). Considerando os grupos em an?lise, utilizou-se a ANOVA com ajustamento com teste de compara??o m?ltipla Dunnett 3T utilizando-se sempre o software SPSS, para um intervalo de confian?a de 95%. Resultados: n?o se verificaram altera??es significativas na composi??o corporal. O grupo blue exercise apresentou melhorias nos resultados m?dios dos testes de aptid?o f?sica na for?a dos membros inferiores (p=0,001) e equil?brio din?mico (p=0,045), ap?s 6 meses. Considerando o bem-estar, o grupo blue exercise apresentou melhorias na pontua??o final ap?s 6 meses, na autonomia ap?s 3 meses e na satisfa??o ap?s 6 meses. Conclus?es: a pr?tica de blue exercise ao fim 6 meses induziu melhorias na for?a muscular dos membros inferiores, equil?brio din?mico e nos indicadores de bem-estar e qualidade de vida, essencialmente na satisfa??o e autonomia em idosos fisicamente ativos e residentes na comunidade. Objective: This study sought to analyze the effects of a 6 months of blue exercise program based on surfing on body composition, strength, balance, cardiorespiratory endurance and wellbeing in physically active elderly people. Methods: using a convenience sample composed of 37 participants (24 women), with a mean age of 71.9?13.8 years old, divided into a blue exercise group (n=12), a control group (n=13) or a group of individuals participating in a free municipally physical exercise program (n=12) was also evaluated. At the beginning, after 3 and 6 months, the following tests were applied: i) bioimpedance; ii) walking 6 min; iii) sitting and standing up from a chair for 30 seconds; iv) 8 Feet Up and Go (TUG) and v) Warwick-Edinburgh Mental Well-being Scale Wellbeing Scale (WEMWS). Assessments were performed before (initial assessment), after 3 and 6 months of blue exercise program that included bodyboarding, walking and functional capacity training sessions. The nonparametric Mann Whitney U test was used to analyze differences between groups. The non-parametric Wilcoxon signed-rank test was used to analyze statistical differences between the different assessment times (initial vs. 3 months; initial vs. 6 months; 3 months vs. 6 months). Considering the groups under analysis, ANOVA with adjustment with multiple comparison test was used. Dunnett 3T, always using the SPSS software, for a confidence interval of 95%. Results: There were no significant changes in body composition. The blue exercise group showed improvements in the average results of the physical fitness tests after 6 months, namely strength of the lower limbs (p=0.001) and dynamic balance (p=0.045). Considering the wellbeing, the blue exercise group showed improvements in the total score and satisfaction domains after 6 months and autonomy domain after 3 months. Conclusions: the practice of blue exercise during a period of 6 months positively intercedes in the improvement of the muscular strength of the lower limbs, dynamic balance and in the indicators of well-being and quality of life, essentially in the satisfaction and autonomy in community-dwelling elderly.