Can the training regimen influence night time physical activity in racehorses?

Physical activity has been widely investigated in horses to elucidate locomotion characteristics and behavior. However, research in real environment of training stables is limited. The objective of this study was to evaluate the effect of training regimen on night time physical activity of racehorses. Physical activities of twenty animals were monitored during the night time using accelerometers. The animals were compared in terms of training regimen: horses subjected to training on continual days, and horses subjected to training on intermittent days; age and sex were also considered. The variables analyzed were: counts per minute, percentage of time in (sedentary, light, moderate and vigorous) physical activity. Statistical analysis was performed by the PROCGLM procedure (ANOVA) and the means were calculated by Tukey's test. The training regimen impacts the physical activity of thoroughbreds. The mean counts per minute showed a higher physical activity in the intermittent trained animals in relation with continuously trained animals. The continuously trained animals presented a greater percentage of time in sedentary physical activity than those intermittent trained. However, intermittently trained horses spent a larger percentage of time in moderate and vigorous physical activity, in comparison with continuously trained animals. In conclusion, racehorses subject to training on continual days have lower physical activity in the night time than those that train on intermittent days.

Myofibrillar protein synthesis and muscle hypertrophy individualized responses to systematically changing resistance training variables in trained young men.

The manipulation of resistance training (RT) variables is used among athletes, recreational exercisers, and compromised populations (e.g., elderly) attempting to potentiate muscle hypertrophy. However, it is unknown whether an individual's inherent predisposition dictates the RT-induced muscle hypertrophic response. Resistance-trained young [26 (3) y] men (n = 20) performed 8 wk unilateral RT (2 times/wk), with 1 leg randomly assigned to a standard progressive RT [control (CON)] and the contralateral leg to a variable RT (VAR; modulating exercise load, volume, contraction type, and interset rest interval). The VAR leg completed all 4 RT variations every 2 wk. Bilateral vastus lateralis cross-sectional area (CSA) was measured, pre- and post-RT and acute integrated myofibrillar protein synthesis (MyoPS) rates were assessed at rest and over 48 h following the final RT session. Muscle CSA increase was similar between CON and VAR (P > 0.05), despite higher total training volume (TTV) in VAR (P < 0.05). The 0-48-h integrated MyoPS increase postexercise was slightly greater for VAR than CON (P < 0.05). All participants were considered "responders" to RT, although none benefited to a greater extent from a specific protocol. Between-subjects variability (MyoPS, 3.30%; CSA, 37.8%) was 40-fold greater than the intrasubject (between legs) variability (MyoPS, 0.08%; CSA, 0.9%). The higher TTV and greater MyoPS response in VAR did not translate to a greater muscle hypertrophic response. Manipulating common RT variables elicited similar muscle hypertrophy than a standard progressive RT program in trained young men. Intrinsic individual factors are key determinants of the MyoPS and change in muscle CSA compared with extrinsic manipulation of common RT variables.NEW & NOTEWORTHY Systematically manipulating resistance training (RT) variables during RT augments the stimulation of myofibrillar protein synthesis (MyoPS) and training volume but fails to potentiate muscle hypertrophy compared with a standard progressive RT. Any modest further MyoPS increase and higher training volumes do not reflect in a greater hypertrophic response. Between-subject variability was 40-fold greater than the variability promoted by extrinsic manipulation of RT variables, indicating that individual intrinsic factors are stronger determinants of the hypertrophic response.

Influência da ordem de execução de exercícios com pesos sobre o volume total de treino quando a carga é ajustada de acordo com a sequência / Influence of the execution order of weight exercises on total training volume when load is adjusted according to the sequence

O objetivo do presente estudo foi analisar a influência de diferentes ordens de execução de exercícios com pesos sobre o volume total de treino. Dez homens (27,0±5,2 anos; 68,0±7,9 kg; 175,0±7,0 cm; 22,0±2,3 kg/m2) realizaram duas sessões experimentais: sequência A (SEQA - iniciada com exercícios para os grandes grupos musculares) e sequência B (SEQB - iniciada com exercício para os pequenos grupos musculares). Na SEQA, os exercícios foram executados na seguinte ordem: supino reto, puxada atrás, desenvolvimento, tríceps no pulley, rosca direta, cadeira extensora, mesa flexora e panturrilha no leg press. Na SEQB adotou-se a ordem: rosca direta, tríceps no pulley, desenvolvimento, puxada atrás, supino reto, panturrilha no leg press, mesa flexora e cadeira extensora. As cargas de treino foram ajustadas previamente, de acordo com a posição do exercício dentro de cada sequência. O volume total da sessão de treino foi semelhante entre as sessões (SEQA= 82050 ± 6258 kg e SEQB= 85466 ± 9614 kg; P>0,05). Diferenças significantes foram identificadas no volume total entre as sequências nos exercícios supino reto (SEQA > SEQB; P<0,05) e tríceps no pulley (SEQB > SEQA; P<0,05). Os resultados sugerem que a ordem de execução dos exercícios não influencia o volume total de treino da sessão quando a carga é ajustada de acordo com a posição do exercício na sequência.

The purpose of the present study was to analyze the influence of different execution order of weight exercises on total training volume. Ten men (27.0±5.2 years, 68.0±7.9 kg, 175.0±7.0 cm, 22.0±2.3 kg/m2) underwent two experimental sessions: sequence A (SEQA ­ beginning with exercises to large muscle groups) and sequence B (SEQB ­ beginning with exercise to small muscle groups). SEQA was composed by the following exercises' order: bench press, pulldown, shoulder press, triceps pushdown, arm curl, leg extension, leg curl, and calf raises on leg press machine. SEQB had the following order: arm curl, triceps pushdown, shoulder press, pulldown, bench press, calf raises on leg press machine, leg curl, and leg extension. The load used in each exercise was previously adjusted according to the exercise position within the sequence. Total training volume was similar between the sessions (SEQA= 82050 ± 6258 kg and SEQB= 85466 ± 9614 kg; P>0.05). Significant differences were found in total volume between the sequences for bench press (SEQA > SEQB, P<0.05) and triceps pushdown (SEQB > SEQA, P<0.05). The results suggest that the order of exercises does not influence total volume of the weight training session when the load is adjusted according to the exercise position within the sequence.