O objetivo desse estudo foi verificar o efeito de diferentes volumes de treinamento de força na força máxima de membros inferiores e na hipertrofia do reto femoral e do vasto lateral após quatro, oito e doze semanas em indivíduos treinados em força. Vinte e seis indivíduos jovens saudáveis do sexo masculino (idade 23,6 ± 4,6 anos, massa corporal 76,6 ± 7,5 kg, estatura 1,75 ± 0,1 cm), com tempo médio de treinamento de força (4,7 ± 4,1 anos) foram divididos em três grupos experimentais, treinamento de força alto volume (TFAV, n = 8), treinamento de força médio volume (TFMV, n = 9) e treinamento de força baixo volume (TFBV, n = 9). As medidas de força dinâmica máxima (1RM) e de área de secção transversa muscular (ASTM) do reto femoral (RF) e do vasto lateral (VL) foram realizadas nos momentos pré- treinamento, pós quatro semanas, pós oito semanas e pós-treinamento. O volume total de treinamento apresentou aumento estatístico para todos os grupos TFAV (p < 0,0001), TFMV (p < 0,0001) e TFBV (p < 0,0001) ao longo do período experimental. Os valores de 1RM aumentaram de maneira significativa após a oitava semana de treinamento TFAV (11,8 ± 4,7%; p < 0,0001) e TFMV (12,1 ± 8,5%; p < 0,0001) e TFBV (9,6 ± 7,3%; p < 0,001) e no pós-treinamento TFAV (13,9 ± 3,9%; p < 0,0001), TFMV (16,7 ± 10,8%; p < 0,0001) e TFBV (14,0 ± 8,1%; p < 0,0001) para todos os grupos, porém não foi observado diferença entre os grupos. A ASTM do RF apresentou aumento estatístico no pós-treinamento somente para o grupo TFAV (15,0 ± 11,9%; p < 0,0001). Apenas o grupo TFAV aumentou estatisticamente a ASTM do VL após quatro semanas de treinamento (7,71 ± 4,42%; p < 0,0001), porém todos os grupos aumentaram significativamente a ASTM do VL após oito semanas de treinamento TFAV (11,37 ± 3,88%; p < 0,0001), TFMV (9,68 ± 9,36%; p < 0,0001) e TFBV (7,26 ± 3,15%; p < 0,01) e no pós-treinamento TFAV (14,54 ± 4,07%; p < 0,0001), TFMV (14,77 ± 8,24%; p < 0,0001) e TFBV (8,66 ± 3,97%; p < 0,001), porém não foi observado diferença entre os grupos. Os resultados do presente estudo demonstraram que, independente do volume adotado, os ganhos de força máxima foram semelhantes. Por outro lado, a ASTM foi influenciada pelo volume de treinamento, dado que o grupo TFAV foi o único que apresentou aumento significativo da ASTM do RF no pós-treinamento e aumentou a ASTM do VL com apenas quatro semanas de treinamento / The aim of this study was to investigate the effects of different strength training volumes on muscle strength and hypertrophy of the lower limbs after four, eight and twelve weeks of strength training in strength-trained individuals. Twenty-six healthy young males (age 23.6 ± 4.6 years, body mass 76.6 ± 7.5 kg, height 1.75 ± 0.1 cm), with an average experience of strength training (4.7 ± 4.1 years) were divided into three groups, high-volume strength training (TFAV, n = 8), mid-volume strength training (TFMV, n = 9) and low-volume strength training (TFBV, n = 9). Maximum dynamic strength (1RM) and muscle cross-sectional area (MCSA) of the rectus femoris (RF) and vastus lateralis (VL) were measured at baseline, after four weeks, after eight weeks and post-training. The total training volume significantly increased for the groups TFAV (p < 0.0001), TFMV (p < 0.0001) and TFBV (p < 0.0001) throughout the experimental period. The 1RM values increased after the eighth weeks of training, compared to baseline values, for the TFAV (11.8 ± 4.7%; p < 0.0001), TFMV (12.1 ± 8.5%; p < 0.0001), and TFBV (9.6 ± 7.3%; p < 0.001) groups, and post-training TFAV (13.9 ± 3.9%; p < 0.0001), TFMV (16.7 ± 10.8%; p < 0.0001) and TFBV (14.0 ± 8.1%; p < 0.0001) for all groups, with no difference between groups. Only TFAV group presented higher RF MCSA values at post-training (15.0 ± 11.9%; p < 0.0001). Furthermore, only TFAV significantly increased the VL MCSA after four weeks of training (7.71 ± 4.42%; p < 0.0001). All of the groups presented significantly greater VL MCSA than baseline values at eight weeks TFAV (11.37 ± 3.88%; p < 0.0001), TFMV (9.68 ± 9.36%; p < 0.0001) and TFBV (7.26 ± 3.15%; p < 0.01) and at post-training TFAV (14.54 ± 4.07%; p < 0.0001), TFMV (14.77 ± 8.24% ; p < 0.0001) and TFBV (8.66 ± 3.97%; p < 0.001), with no difference between groups. The results of this study demonstrated that, regardless of the adopted volume, the muscle strength gains were similar. On the other hand , MCSA was influenced by the training volume, since the TFAV was the only group that showed significant increase of RF MCSA post- training and increased VL MCSA with only four weeks of training

O objetivo desse estudo foi verificar o efeito de diferentes volumes de treinamento de força na força máxima de membros inferiores e na hipertrofia do reto femoral e do vasto lateral após quatro, oito e doze semanas em indivíduos treinados em força. Vinte e seis indivíduos jovens saudáveis do sexo masculino (idade 23,6 ± 4,6 anos, massa corporal 76,6 ± 7,5 kg, estatura 1,75 ± 0,1 cm), com tempo médio de treinamento de força (4,7 ± 4,1 anos) foram divididos em três grupos experimentais, treinamento de força alto volume (TFAV, n = 8), treinamento de força médio volume (TFMV, n = 9) e treinamento de força baixo volume (TFBV, n = 9). As medidas de força dinâmica máxima (1RM) e de área de secção transversa muscular (ASTM) do reto femoral (RF) e do vasto lateral (VL) foram realizadas nos momentos pré- treinamento, pós quatro semanas, pós oito semanas e pós-treinamento. O volume total de treinamento apresentou aumento estatístico para todos os grupos TFAV (p < 0,0001), TFMV (p < 0,0001) e TFBV (p < 0,0001) ao longo do período experimental. Os valores de 1RM aumentaram de maneira significativa após a oitava semana de treinamento TFAV (11,8 ± 4,7%; p < 0,0001) e TFMV (12,1 ± 8,5%; p < 0,0001) e TFBV (9,6 ± 7,3%; p < 0,001) e no pós-treinamento TFAV (13,9 ± 3,9%; p < 0,0001), TFMV (16,7 ± 10,8%; p < 0,0001) e TFBV (14,0 ± 8,1%; p < 0,0001) para todos os grupos, porém não foi observado diferença entre os grupos. A ASTM do RF apresentou aumento estatístico no pós-treinamento somente para o grupo TFAV (15,0 ± 11,9%; p < 0,0001). Apenas o grupo TFAV aumentou estatisticamente a ASTM do VL após quatro semanas de treinamento (7,71 ± 4,42%; p < 0,0001), porém todos os grupos aumentaram significativamente a ASTM do VL após oito semanas de treinamento TFAV (11,37 ± 3,88%; p < 0,0001), TFMV (9,68 ± 9,36%; p < 0,0001) e TFBV (7,26 ± 3,15%; p < 0,01) e no pós-treinamento TFAV (14,54 ± 4,07%; p < 0,0001), TFMV (14,77 ± 8,24%; p < 0,0001) e TFBV (8,66 ± 3,97%; p < 0,001), porém não foi observado diferença entre os grupos. Os resultados do presente estudo demonstraram que, independente do volume adotado, os ganhos de força máxima foram semelhantes. Por outro lado, a ASTM foi influenciada pelo volume de treinamento, dado que o grupo TFAV foi o único que apresentou aumento significativo da ASTM do RF no pós-treinamento e aumentou a ASTM do VL com apenas quatro semanas de treinamento / The aim of this study was to investigate the effects of different strength training volumes on muscle strength and hypertrophy of the lower limbs after four, eight and twelve weeks of strength training in strength-trained individuals. Twenty-six healthy young males (age 23.6 ± 4.6 years, body mass 76.6 ± 7.5 kg, height 1.75 ± 0.1 cm), with an average experience of strength training (4.7 ± 4.1 years) were divided into three groups, high-volume strength training (TFAV, n = 8), mid-volume strength training (TFMV, n = 9) and low-volume strength training (TFBV, n = 9). Maximum dynamic strength (1RM) and muscle cross-sectional area (MCSA) of the rectus femoris (RF) and vastus lateralis (VL) were measured at baseline, after four weeks, after eight weeks and post-training. The total training volume significantly increased for the groups TFAV (p < 0.0001), TFMV (p < 0.0001) and TFBV (p < 0.0001) throughout the experimental period. The 1RM values increased after the eighth weeks of training, compared to baseline values, for the TFAV (11.8 ± 4.7%; p < 0.0001), TFMV (12.1 ± 8.5%; p < 0.0001), and TFBV (9.6 ± 7.3%; p < 0.001) groups, and post-training TFAV (13.9 ± 3.9%; p < 0.0001), TFMV (16.7 ± 10.8%; p < 0.0001) and TFBV (14.0 ± 8.1%; p < 0.0001) for all groups, with no difference between groups. Only TFAV group presented higher RF MCSA values at post-training (15.0 ± 11.9%; p < 0.0001). Furthermore, only TFAV significantly increased the VL MCSA after four weeks of training (7.71 ± 4.42%; p < 0.0001). All of the groups presented significantly greater VL MCSA than baseline values at eight weeks TFAV (11.37 ± 3.88%; p < 0.0001), TFMV (9.68 ± 9.36%; p < 0.0001) and TFBV (7.26 ± 3.15%; p < 0.01) and at post-training TFAV (14.54 ± 4.07%; p < 0.0001), TFMV (14.77 ± 8.24% ; p < 0.0001) and TFBV (8.66 ± 3.97%; p < 0.001), with no difference between groups. The results of this study demonstrated that, regardless of the adopted volume, the muscle strength gains were similar. On the other hand , MCSA was influenced by the training volume, since the TFAV was the only group that showed significant increase of RF MCSA post- training and increased VL MCSA with only four weeks of training

Highly-trained athletes are accustomed to varied and high-volume based exercise stimuli and eliciting adaptation in individuals already possessing the necessary physiology to compete at the highest level is difficult. Therefore, identifying novel, potent and time efficient methods of achieving cumulative training stress is a continual quest for coaches and exercise scientists. This thesis examined the acute and chronic effects of manipulating exercise and recovery during brief all-out sprint cycling on adaptive responses favouring enhanced endurance capacity. Chapter 3 highlighted that low-volume non-work matched all-out sprint cycling, whether it be interval- (4 x 30 s bouts) or continuous based (1 x 2 min bout) provides a similarly potent stimulus for the acute induction of cell signalling pathways and key growth factors associated with mitochondrial biogenesis and angiogenesis in trained individuals. In line with manipulating recovery and in attempting to identify a novel and potent exercise intervention capable of giving athletes more return on their training investment, Chapters 4-6 investigated the efficacy of combining sprint interval training with post-exercise blood flow restriction (BFR). Firstly, it was demonstrated that BFR potentiates HIF-1α mRNA expression in response to SIT, tentatively suggesting an enhanced stimulus for hypoxia- and/or metabolic-mediated cell signalling associated with mitochondrial biogenesis and angiogenesis over SIT alone. Secondly, four weeks of SIT combined with post-exercise BFR provides a greater training stimulus over SIT alone in trained individuals to enhance VO2max (4.7 v 1.1 % change) and MAP (3.8 v 0.2 % change), but not 15-km TT performance. Finally, in response to four weeks of SIT combined with post-exercise BFR, an international female track sprint cyclist increased her CP and W by 7 and 2 % and VO2max and absolute MAP by 3 and 4 %, respectively. Through a combination of an acute in vivo molecular experiment, a training study and an athlete case study, this thesis has introduced a potentially potent and novel training concept that appears capable of augmenting aerobic capacity.