The aim of this study was to characterize the specifics of the sprint technique during the transition from start block into sprint running in well-trained sprinters. Twenty-one sprinters (11 men and 10 women), equipped with 74 spherical reflective markers, executed an explosive start action. An opto-electronic motion analysis system consisting of 12 MX3 cameras (250 Hz; 325,000 pixels) and two Kistler force plates (1000 Hz) was used to collect the three-dimensional (3D) marker trajectories and ground reaction forces (Nexus, Vicon). The 3D kinematics, joint kinetics, and power were calculated (Opensim) and were time normalized to 100% from the first action after gunshot until the end of second stance after block clearance (Matlab). The results showed that during the first stance, power generation at the knee plays a significant role in obtaining an effective transition, representing 31% of power generation in the lower limb, in the absence of preceding power absorption. Furthermore, the sprinter actively searches a more forward leaning position to maximize horizontal velocity. Since success during sprinting from the second stance onwards involves high hip and ankle activation, the above-mentioned three characteristics are specific skills required to successfully conclude the transition from start block into sprint running.

Objective: The aim of this study was to determine the impact of demographic, socioeconomic and nutritional determinants on daily versus non-daily sugar-sweetened and artificially sweetened beverage consumption. Methods: Cross-sectional design in 1852 military men. Using mailed questionnaires, sugar-sweetened and artificially sweetened beverage consumption was recorded. Principal component analysis was used for dietary pattern analysis. Results: Sugar-sweetened and artificially sweetened beverages were consumed daily by 36.3% and 33.2% of the participants, respectively. Age, body mass index (BMI), non-smoking and income were negatively related to sugar-sweetened beverage consumption. High BMI and trying to lose weight were related to artificially sweetened beverages consumption. Three major patterns were obtained from principal component analysis: first, the 'meat pattern', was loaded for red meats and processed meats; second, the 'healthy pattern', was loaded for tomatoes, fruit, whole grain, vegetables, fruit, fish, tea and nuts; finally, the 'sweet pattern' was loaded for sweets, desserts, snacks, high-energy drinks, high-fat dairy products and refined grains. The sugar-sweetened beverage consumption was strongly related with both the meat and sweet dietary patterns and inversely related to the healthy dietary pattern. The artificially sweetened beverage consumption was strongly related with the sweet and healthy dietary pattern. Conclusions: Daily consumption of sugar-sweetened beverages was inversely associated with a healthy dietary pattern. Daily consumption of artificially sweetened beverages was clearly associated with weight-loss intention.

Background During the pregnancy and postpartum period, both women and men experience physiological and psychological changes, which may negatively impact their eating behavior. A clear understanding of determinants of changes in eating behavior during this period is needed to facilitate the development of targeted family-based interventions countering unfavorable dietary changes during this critical life period. Methods Thirteen focus group discussions targeting determinants of changes in eating behavior during pregnancy and postpartum were conducted, involving a total of 74 expecting and first-time parents. A semi-structured question guide was used to facilitate the discussions. An inductive thematic approach was used to derive main and sub-categories of determinants from the data. The Determinants of Nutrition and Eating (DONE)-framework was employed to systematically organize and label the categories and determinants. Results Two frameworks were developed; one for the pregnancy and one for the postpartum period, comprising determinants of changes in eating behavior in both women and men. Three main levels of determinants were identified: (1) the individual level, including psychological (e.g., ‘health consciousness’), situational (e.g., ‘effort and convenience’) and biological (e.g., ‘discomfort’); (2) the interpersonal level (e.g., ‘social influence’) and (3) the environmental level, including micro- and meso/macro (e.g., ‘home/environment food availability’). Determinants acting as barriers (e.g., ‘time constraints’) or facilitators (e.g., ‘being a role model’) were identified. Many determinants were mentioned during both (e.g., ‘food knowledge’) or just one investigated period (e.g., ‘physiological changes’ during pregnancy, ‘influence of the baby’ postpartum). Finally, some were described by both parents (e.g., ‘self-regulation’), whereas others were mentioned by women (e.g., ‘(perceived) food safety’) or men (e.g., ‘other priorities’) only. Conclusion The developed frameworks set the foundation for the development of future family-based interventions and may be used already by healthcare providers to provide dietary guidance and support for women and men transitioning into parenthood. A focus on the interplay of individual factors at the biological and psychological level together with situational difficulties during pregnancy is recommended. Postpartum, focus should go to support first-time parents to obtain balance of both maintaining one’s own health and taking care of the baby, on improving self-regulation skills, and on coping with related situational constraints.

The aim of this study was to relate the contribution of lower limb joint moments and individual muscle forces to the body centre of mass (COM) vertical and horizontal acceleration during the initial two steps of sprint running. Start performance of seven well-trained sprinters was recorded using an optoelectronic motion analysis system and two force plates. Participant-specific torque-driven and muscle-driven simulations were conducted in OpenSim to quantify, respectively, the contributions of the individual joints and muscles to body propulsion and lift. The ankle is the major contributor to both actions during the first two stances, with an even larger contribution in the second compared to the first stance. Biarticular gastrocnemius is the main muscle contributor to propulsion in the second stance. The contribution of the hip and knee depends highly on the position of the athlete: During the first stance, where the athlete runs in a forward bending position, the knee contributes primarily to body lift and the hip contributes to propulsion and body lift. In conclusion, a small increase in ankle power generation seems to affect the body COM acceleration, whereas increases in hip and knee power generation tend to affect acceleration less.

A first objective of the present study was to estimate the acid-base balance of the food intake in vegetarians and non-vegetarians. A second objective was to evaluate if additional input of specific food items on the existing potential renal acid load (PRAL) list was necessary for the comparison of the two dietary patterns. Thirty vegetarians between the age of 18 and 30 years were matched for sex, age and BMI with 30 non-vegetarians. Based on the 3-days food diaries the acid-base status of the food intake was estimated using the PRAL method. Mean PRAL values as estimated with the standard table yielded an alkaline load of -5.4 +/- 14.4 mEq/d in the vegetarians compared to an acid load of 10.3 +/- 14.4 mEq/d in the nonvegetarians (p<0.001). Mean PRAL values as estimated with the extended table yielded an alkaline load of -10.9 +/-19.7 mEq/d in the vegetarians compared to an acid load of 13.8 +/- 17.1 mEq/d for the non-vegetarians (p<0.001). The findings of this study indicate that vegetarian food intake produces more alkaline outcomes compared to non-vegetarian diets. The use of the standard PRAL table was sufficient for discrimination between the two diets.

BackgroundEpidemiological studies indicate that a well balanced vegetarian diet offers several health benefits including a lower prevalence of prosperity diseases in vegetarians compared to omnivores. It was the purpose of the present study to compare nutritional and physical characteristics in matched samples of institutionalized vegetarian (V) and non-vegetarian (NV) elderly.MethodsTwenty-two female and 7 male V (females: 84.1 ± 5.1yrs, males: 80.5 ± 7.5yrs) and 23 female and 7 male NV (females: 84.3 ± 5.0yrs, males: 80.6 ± 7.3yrs) participated. All subjects were over 65 years of age, and free of major disease or physical handicap. Dietary intake, blood profile, anthropometrics, and handgrip strength were determined.ResultsMean daily energy intake was 6.8 ± 2.0MJ in V females, and 8.0 ± 1.4MJ in the NV females, only the V did not reach the recommended value of 7.8 MJ. Male V and NV had a mean daily energy intake of 8.7 ± 1.6MJ and 8.7 ± 1.2MJ respectively (RDI: 8.8 MJ). Mean carbohydrate intake was significantly below the RDI in NV only (female V: 47.8 ± 7.5E%, female NV: 43.3 ± 4.6E%, male V: 48.1 ± 6.4E%, male NV: 42.3 ± 3.6E%), while protein (female V: 17.3 ± 3.4E%, female NV: 19.5 ± 3.5E%, male V: 17.8 ± 3.4E%, male NV: 21.0 ± 2.0E%), and saturated fat intake (female V: 25.4 ± 8.2 g/day, female NV: 32.2 ± 6.9 g/day, male V: 31.4 ± 12.9 g/day, male NV: 33.4 ± 4.7 g/day) were too high in both V and NV. Mean micronutrient intakes met the RDI's in all 4 groups. Mean blood concentrations for vitamin B12, folic acid, iron, and calcium were normal in all 4 groups. Mean zinc blood serum was below the reference value in all groups, whereas estimated zinc intake was in agreement with the RDI. The mean blood cholesterol concentration was above the 200 mg/dl upper limit in the V group (213 ± 40 mg/dl) and below that limit in the NV (188 ± 33 mg/dl) group. Mean BMI was 26.1 ± 4.7 kg/m2 in the female V, 26.8 ± 3.7 kg/m2 in the female NV, 23.5 ± 3.7 kg/m2 in the male V, and 25.2 ± 4.2 kg/m2 in the male NV. V and NV scored below the reference values for the handgrip strength test.ConclusionsGenerally, our results show a similar profile for V and NV concerning dietary intake, blood values, and physical characteristics. Attention should be paid to the intake of mono- and disaccharides and saturated fats in the diet of both V and NV. This study indicates that a vegetarian lifestyle has no negative impact on the health status at older age.

Macronutrient intake, height, weight, and body composition of 60 adolescent sprint athletes were estimated every 6 months over 3 years. Seven-day food records were analysed based on the Belgian and Dutch food databanks. The age of participants at the start of the 3-year study was 14.8 ± 1.6 years for female athletes and 14.7 ± 1.9 years for male athletes. Girls and boys gained height (3.4 ± 4.6 cm and 5.9 ± 6.6 cm respectively) and weight (5.6 ± 3.5 kg and 8.7 ± 5.5 kg respectively), whereas percent body fat remained unchanged in both girls and boys (around 17.0% and 8.5% respectively). Mean protein intake of around 1.5 g · kg⁻¹ body weight was within recommendations on each occasion for both sexes. Carbohydrate intakes between 5 and 7 g · kg⁻¹ body weight support a training programme of moderate intensity. Total and saturated fat intakes were high at the start of the study (girls: 31.8 ± 3.5% and 12.2 ± 2.0% of energy intake; boys: 30.3 ± 4.6% and 12.0 ± 1.9% of energy intake) and it appeared to be difficult to achieve and maintain lower intakes. Consistent low fluid intakes around 40 ml · kg⁻¹ body weight were observed. General non-stringent advice for improvement of the diet resulted in significant favourable changes only for the consumption of wholegrain bread, vegetables, and soft drinks. Dietary habits of adolescent sprint athletes are not always according to guidelines and are relatively stable but repeated advice can induce moderate improvements.

This study compared the effect of a resistance training (RT) program with machines, free weights, or a combination of both on changes in anthropometrics, strength, and functional ability in novice adult males. Thirty-six male novices in RT (18–45 years) followed a 10-week RT program. Participants were randomly assigned to one of three groups (N = 12 each): machines only; free weights only; or switching from machines to free weights (after 5 weeks). Muscle size (circumferences of upper arm, thigh and chest), strength (1 Repetition Maximum) on both machines and free weights, and functional ability (Functional Movement ScreenTM (Functional Movement Systems Inc., Chatham, VA, USA)) were assessed prior to the RT program, halfway at 5 weeks, and within one week after the final training bout. Repeated measures MANOVAs showed no significant time by RT group interactions for the different outcome measures. Regardless of RT group, significant improvements over time were observed for anthropometrics (F = 9.144, p < 0.001), strength (F = 6.918, p < 0.001), and functional ability (F = 25.578, p < 0.001). To conclude, similar gains in muscularity, strength, and functional ability can be expected for male novices in RT regardless of the equipment being used and without a fallback when changing from machines to free weights. Accordingly, any choice of RT equipment can be made, considering individual preferences.