Sprint-based exercise and cognitive function in adolescents

Moderate intensity exercise has been shown to enhance cognition in an adolescent population, yet the effect of high-intensity sprint-based exercise remains unknown and was therefore examined in the present study. Following ethical approval and familiarisation, 44 adolescents (12.6 ± 0.6 y) completed an exercise (E) and resting (R) trial in a counter-balanced, randomised crossover design. The exercise trial comprised of 10 × 10 s running sprints, interspersed by 50 s active recovery (walking). A battery of cognitive function tests (Stroop, Digit Symbol Substitution (DSST) and Corsi blocks tests) were completed 30 min pre-exercise, immediately post-exercise and 45 min post-exercise. Data were analysed using mixed effect models with repeated measures. Response times on the simple level of the Stroop test were significantly quicker 45 min following sprint-based exercise (R: 818 ± 33 ms, E: 772 ± 26 ms; p = 0.027) and response times on the complex level of the Stroop test were quicker immediately following the sprint-based exercise (R: 1095 ± 36 ms, E: 1043 ± 37 ms; p = 0.038), while accuracy was maintained. Sprint-based exercise had no immediate or delayed effects on the number of items recalled on the Corsi blocks test (p = 0.289) or substitutions made during the DSST (p = 0.689). The effect of high intensity sprint-based exercise on adolescents' cognitive function was dependant on the component of cognitive function examined. Executive function was enhanced following exercise, demonstrated by improved response times on the Stroop test, whilst visuo-spatial memory and general psycho-motor speed were unaffected. These data support the inclusion of high-intensity sprint-based exercise for adolescents during the school day to enhance cognition

Breakfast glycaemic index and exercise: combined effects on adolescents' cognition

The aim of the present study was to examine the combined effects of breakfast glycaemic index (GI) and a mid-morning bout of exercise on adolescents’ cognitive function. Participants were randomly allocated to a high or low GI breakfast group in a mixed research design, where each participant completed two experimental trials (exercise and resting). Forty-two adolescents (12.4±0.5 years old), undertook a bout of exercise (ten repeats of level one of the multi-stage fitness test; exercise trial) or continued to rest (resting trial) following consumption of either a high or low GI breakfast. A battery of cognitive function tests (visual search test, Stroop test and Sternberg paradigm) was completed 30 min before and 45 min following the exercise. Average heart rate during exercise was 170±15 beats.min-1. On the complex level of the Stroop test, response times improved across the morning following the low GI breakfast on both the exercise and resting trials, though the improvement was greatest on the exercise trial. However, response times only improved on the resting trial following the high GI breakfast (p = 0.012). On the 5 letter level of the Sternberg paradigm, response times improved across the morning following the low GI breakfast (regardless of exercise) and only on the exercise trial following the high GI breakfast (p = 0.019). The findings of the present study suggest that the combined effects of breakfast GI and exercise in adolescents depend upon the component of cognitive function examined. A low GI breakfast and mid-morning bout of exercise were individually beneficial for response times on the Sternberg paradigm, whereas they conferred additional benefits for response times on the Stroop test

Short communication. Sensory evaluation of commercial beef produced in Uruguay and three European countries

The main goal of this study was to characterize and compare the organoleptic quality of beef from Uruguay and from three European countries. In Uruguay, 40 Hereford steers were raised exclusively under grazing conditions up to either two or three years old. Meat samples were aged for 20 days, matching commercial conditions. In Europe, one commercial local beef type, with two ageing times (7 and 20 days), from Germany, Spain and the United Kingdom were compared with Uruguayan beef samples, using 20 animals of each treatment per country. The highest beef odour and flavour scores were for the British beef aged for 7 days followed by the German and Uruguayan meat. Beef from the youngest animals (Spanish) and, especially from the UK, were up to 42 and 62%, respectively, more tender than German beef, all of them aged for 7 days. The highest juiciness scores were for the Uruguayan three years old beef. Long ageing periods (20 days) tended to produce off-aromas in the case of the British beef, which showed the highest scores in abnormal odour flavour intensities. European beef showed a significant variability in its sensory attributes that could not be justified only by differences in the ageing time. Uruguayan beef has meat with similar sensory characteristics to some European meats, and because of that it could have good consumer acceptability.This research was part of cooperative agreement among INIA Uruguay, INIA Spain, and the AECID Spain, with the participation of the National Meat Institute (INAC, Uruguay).info:eu-repo/semantics/publishedVersio