Gastric emptying and orocaecal transit time of meals containing lactulose or inulin in men

The H2 breath test is ideal for orocaecal transit time (OCTT) measurement, as it is non-invasive and inexpensive. Indigestible substrates added to a test meal are metabolised by the colonic bacteria, resulting in the production of H2 which is detected in end-exhalation breath. However, the substrates themselves can alter the transit times in the gastrointestinal tract. The aim of the present study is to compare OCTT and gastric emptying (GE) when lactulose in liquid (L-L), solid lactulose (L-S) and solid inulin (IN-S) are added to a test meal, and subsequently, to examine if inulin alters GE. Firstly, ten male volunteers were tested on three occasions. Volunteers ate a pancake breakfast containing 100 mg of 13C-octanoic acid and either 12 g of L-L, 12 g of L-S or 12 g of IN-S in a randomised order. Secondly, seven male volunteers were tested twice with meals containing either 12 g of IN-S or no substrate (NO-S). L-L induced the shortest OCTT (85.3 (SD 42.8) min) compared with L-S (162.4 (SD 62.6) min) and inulin (292.4 (SD 66.7) min; P¼0.007). GE half-time and lag phase (L-L: 61 (SD 9); L-S: 57 (SD 10); IN-S: 52 (SD 10) min; P¼0.005) were also affected, with L-L being the slowest. Thirdly, inulin reduced GE lag and latency phases (P,0•05) compared with NO-S. Lactulose accelerates OCTT but delays GE compared with inulin. Inulin accelerates the onset of stomach emptying, but it has no effect on GE half-time. For these reasons, inulin is the preferred substrate for the H2 breath test

The role of fat in gastric emptying and satiety : acute and chronic effects

Dietary fat is an important factor in the aetiology of obesity and the metabolic syndrome. It has been widely debated whether gastric emptying (GE) is altered in obesity. GE times have been reported as both longer and shorter in obese individuals compared with matched lean individuals. However, the general consensus is that GE is accelerated and satiety is lower in obesity. Research has implicated a high-fat (HF) diet in these findings. A single HF meal has a longer GE time than a low-fat meal and can even delay GE of the subsequent meal. However, an HF diet has shown different effects. Feeding a HF diet adapts gastrointestinal function to reduce GE times in comparison with a low-fat diet. Increased GE may lead to decreased satiety and faster onset of subsequent eating episodes. Further results have suggested that consuming an HF diet for 14 d increases the GE rate of HF food but not low-fat food. Consuming HF diets for 2 weeks has also been shown to increase food intake. Decreased satiation following an HF diet may cause increased food intake and a positive energy balance, potentially resulting in a gradual increase in adiposity. Recent results have suggested that gastrointestinal transit is accelerated following only 3 d on a HF diet. The variable GE times reported in obesity may be associated with interactions between the HF diet and obesity and not simply the obese state

The relationship between previous hamstring injury and the concentric isokinetic knee muscle strength of Irish gaelic footballers

Background: Hamstring injury is one of the most common injuries affecting gaelic footballers, similar to other field sports. Research in other sports on whether residual hamstring weakness is present after hamstring injury is inconsistent, and no study has examined this factor in irish gaelic footballers. The aim of this study was to examine whether significant knee muscle weakness is present in male Irish gaelic footballers who have returned to full activity after hamstring injury. Methods: The concentric isokinetic knee flexion and extension strength of 44 members of a university gaelic football team was assessed at 60, 180 and 300 degrees per second using a Contrex dynamometer. Results: Fifteen players (34%) reported a history of hamstring strain, with 68% of injuries affecting the dominant (kicking) limb. The hamstrings were significantly stronger (p 0.05) using this comparison. The previously unilaterally injured hamstrings were significantly weaker (p < 0.05) than uninjured limbs however, when matched for dominance. The hamstring to opposite hamstring (H:oppH) strength ratio of the previously injured players was also found to be significantly lower (p < 0.05) than that of the uninjured players. Conclusion: Hamstring muscle weakness was observed in male Irish gaelic footballers with a history of hamstring injury. This weakness is most evident when comparisons are made to multiple control populations, both within and between subjects. The increased strength of the dominant limb should be considered as a potential confounding variable in future trials. The study design does not allow interpretation of whether these changes in strength were present before or after injury

Early - phase strength gains during traditional resistance training compared with an upper - body air - resistance training

The purpose of this study was to examine the early-phase adaptations of traditional dynamic constant external resistance (DCER) training vs. a portable upper-body training device (Fortex). The Fortex is a concentric training device based on air resistance. Contractions using this device are slow (1.5–3 s) and have a limited range of motion. The exercises potentially allow maximal muscle action during each contraction. Healthy, sedentary men (n = 30) were assigned to begin either 8 weeks of weight training (W, n = 12) or 8 weeks of Fortex training (F, n = 9), and were compared with a control group (C, n = 9). Exercises were chosen for the W group that would train similar muscle groups and contain a similar volume of repetitions as the F group. However, movement patterns and force curves were not identical. Increases in the upper-arm cross-sectional area were not detected in any of the groups. Both training groups showed strength gains in the various strength tests that were distinct from each other. Our results indicate that both Fortex and DCER training proved effective in eliciting strength gains in sedentary men over an 8- week training period. There are, however, limitations with the Fortex in terms of progression needs and training asymmetry that indicate it should be used as a complement to other training

Lower back pain in physically demanding college academic programs : a questionnaire based study

Background: Lower back pain (LBP) is ranked first as a cause of disability and inability to work, and is expected to affect up to 90% of the worlds population at some point in their lifetime. The annual first time incidence of LBP is 5%, and the annual prevalence (i.e. those suffering at time of questioning) is between 15 and 63%. Prospective studies demonstrate that low back problems do not display a six-week spontaneous recovery pattern, as was once believed. The condition is regularly seen to worsen over time, becoming a chronic disorder, influenced by both physical and psychosocial factors. Methods: The current study assessed the level of LBP amongst students engaged in educational programs that were physically demanding, and its influence on lower back problems. A 1-year retrospective questionnaire consisting of 37 closed, open and multi-choice questions was designed to ascertain self-reported information on the occurrence, cause and type of LBP. Treatment, care seeking and general knowledge regarding LBP were also recorded. Students were enrolled in BSc Equine Science, BSc Physical Education and BSc Sports & Exercise Science degree programs and a total number of 188 valid questionnaires were collected. Results: The self reported, anthropometrical data for participants in this study are: age 20.9 ± 2.7 yrs; height 171.8 ± 9.3 cm; weight 66.7 ± 10.4 kg; female 64% (n = 120), male 36% (n = 68). The overall self reported prevalence of LBP was 32% (n = 61). Within the LBP population, 77% reported their problem as recurring. Two factors showed significance as having an influence on LBP. They were age (21.6 ± 3.5 yrs, p = 0.005) and hours of personal training physical activity (14.0 ± 8.2 hrs per week, p = 0.02). LBP sufferers also displayed poor management of their condition and an interest in education and treatment of their problem. Conclusion: The current study revealed high prevalence of LBP consistent with that of the literature, and unveiled a recurrence rate and behavioral habits of sufferers, which are warning signs of a more chronic state to come. Novel data presented here offers strong support for the need for prospective injury tracking, plus educational intervention and treatment aimed at prevention of LBP

Impact of seated and standing bicycle riding position on subsequent running performance

This study examined the effects of cycling posture on subsequent running performance similar to the transition phase of a triathlon. Experienced, non-elite triathletes completed two trials of a cycle-run transition. During the last three minutes of a 30 minute cycling bout, at power output equal to lactate threshold, subjects either remained seated (SEAT), or alternated seated and standing cycling (30 s at a time; ALT). Heart rate, RPE, minimum and maximum knee angle, stride frequency and length, and onset and duration of quadriceps and hamstrings activity were obtained at the end of a three-minute control run and at minutes 0, 2, & 4, of running after cycling transition. Repeated Measures ANOVA (condition X minute; p = 0.05) found control was significantly different than minute 0 for stride frequency and length, but not for minimum or maximum knee angle. EMG duration at minute 4 was less than all other time points for both quadriceps and hamstrings. Onset of muscle activity was not different for hamstring or quadriceps. Heart rate and RPE both increased over 15 minutes after transition and were higher for SEAT than ALT, however, there was no interaction (minute by position) for either variable. Results indicated changes in stride rate and length following cycling occur, but disappear within two minutes after the transition to running and do not differ between postures. Changes in duration of muscle activity may be related to changes in stride. Also HR and RPE differ between the SEAT and ALT cycling positions and over time

Effect of cinnamon on gastric emptying, arterial stiffness, postprandial lipemia, glycemia, and appetite responses to high-fat breakfast

Background: Cinnamon has been shown to delay gastric emptying of a high-carbohydrate meal and reduce postprandial glycemia in healthy adults. However, it is dietary fat which is implicated in the etiology and is associated with obesity, type 2 diabetes and cardiovascular disease. We aimed to determine the effect of 3 g cinnamon (Cinnamomum zeylanicum) on GE, postprandial lipemic and glycemic responses, oxidative stress, arterial stiffness, as well as appetite sensations and subsequent food intake following a high-fat meal. Methods: A single-blind randomized crossover study assessed nine healthy, young subjects. GE rate of a high-fat meal supplemented with 3 g cinnamon or placebo was determined using the 13C octanoic acid breath test. Breath, blood samples and subjective appetite ratings were collected in the fasted and during the 360 min postprandial period, followed by an ad libitum buffet meal. Gastric emptying and 1-day fatty acid intake relationships were also examined. Results: Cinnamon did not change gastric emptying parameters, postprandial triacylglycerol or glucose concentrations, oxidative stress, arterial function or appetite (p < 0.05). Strong relationships were evident (p < 0.05) between GE Thalf and 1-day palmitoleic acid (r = -0.78), eiconsenoic acid (r = -0.84) and total omega-3 intake (r = -0.72). The ingestion of 3 g cinnamon had no effect on GE, arterial stiffness and oxidative stress following a HF meal. Conclusions: 3 g cinnamon did not alter the postprandial response to a high-fat test meal. We find no evidence to support the use of 3 g cinnamon supplementation for the prevention or treatment of metabolic disease. Dietary fatty acid intake requires consideration in future gastrointestinal studies. Trial registration: Trial registration number: at http://www.clinicaltrial.gov: NCT0135028

The role of anxiety in golf putting performance

INTRODUCTION: Anxiety’s influence on performance continues to be one of the main research interests for sport psychologists (Hanin, 2000). It is apparent, though, that there is a lack of empirical research characterising the multi-disciplinary effect of anxiety on sports performance. The current study aimed to ascertain biomechanical (accuracy, movement variability) and psychological (anxiety) markers to determine how anxiety affects golf putting. METHOD: 22 healthy subjects (12 male, 10 female, 21.7±2.0 yrs, 175.3±8.1 cm, 76.4±10.0 kg, all data mean±SD) who had played golf recreationally previously but with no recorded handicap were recruited. Subjects performed thirty 3.05 m putts using their own putter under a control and anxiety condition. Anxiety was elevated using environmental cues (e.g. presence of spectators) and a competition scenario. Three-dimensional motion was tracked using a six camera Motion AnalysisTM system operating at 240 Hz. Final ball position from the hole was ascertained using overhead digital photogrammetry. Self reported anxiety was measured pre, during and post putting using standardised self-report anxiety questionnaires. The Competitive State Anxiety Inventory (CSAI) was used to measure state anxiety intensity and direction across three sub scales (i.e. cognitive anxiety, somatic anxiety and selfconfidence). The shorter Mental Readiness Form (MRF) was used to obtain anxiety measures during performance. RESULTS: Significant changes in self-reported anxiety were reported between the control and anxiety conditions. Student’s t-test revealed that performance, as measured by distance from hole was not different in control (0.68±0.52 m) and anxiety conditions (0.56±0.33 m). Females, n=10, significantly worsened their performance under anxiety condition (1.02±0.45 m) compared to control (0.73±0.37 m). Movement analysis showed that swing tempo, represented as a ratio of backswing to downswing time increased significantly (p<0.05), from 0.57 to 0.65 from control to anxious conditions respectively. Total swing time increased by an average 0.16 s for anxious putts and left wrist angle was also more open at impact by 0.97 degrees. CONCLUSION: Results show anxiety did not cause significant change in putting performance overall

Gastrointestinal transit, post-prandial lipaemia and satiety following 3 days high-fat diet in men

Background/Objectives: High-fat (HF) diets of 2 weeks have been shown to accelerate gastric emptying (GE). To date, no studies have shown any alteration in GE following shorter HF diets. The aim of this study was to assess if an HF, high-energy diet of 3 days can adapt gastrointestinal (GI) transit, blood lipids and satiety. Subjects/Methods: Eleven male volunteers participated in a study consisting of three, 3-day interventions each separated by a test day. During the first intervention, volunteers recorded their diet. In the second and third interventions, volunteers repeated their food diary plus either a low-fat yogurt or HF yogurt supplement in randomized order. Test days involved measurement of GE using the 13C octanoic-acid breath-test, mouth-to-caecum transit time (MCTT) using the inulin H2 breath test and satiety using visual analogue scales. Blood samples for measurement of lipaemia were taken using a venous cannula. Results: MCTT was different between the three test days (P¼0.038), with the shortest MCTT following the HF intervention. GE was shortest following the HF intervention. There were no differences in satiety between the interventions. The HF intervention reduced triglycerides, total cholesterol and low-density lipoprotein cholesterol, and increased high-density lipoprotein cholesterol. Conclusion: This study shows that changes in GI transit owing to an HF diet can occur in a time period as short as 3 days

Exercise and postprandial lipaemia: effects on peripheral vascular function, oxidative stress and gastrointestinal transit

Postprandial lipaemia may lead to an increase in oxidative stress, inducing endothelial dysfunction. Exercise can slow gastric emptying rates, moderating postprandial lipaemia. The purpose of this study was to determine if moderate exercise, prior to fat ingestion, influences gastrointestinal transit, lipaemia, oxidative stress and arterial wall function. Eight apparently healthy males (age 23.6 ± 2.8 yrs; height 181.4 ± 8.1 cm; weight 83.4 ± 16.2 kg; all data mean ± SD) participated in the randomised, crossover design, where (i) subjects ingested a high-fat meal alone (control), and (ii) ingested a high-fat meal, preceded by 1 h of moderate exercise. Pulse Wave Velocity (PWV) was examined at baseline, post-exercise, and in the postprandial period. Gastric emptying was measured using the 13C-octanoic acid breath test. Measures of venous blood were obtained prior to and following exercise and at 2, 4 and 6 hours post-ingestion. PWV increased (6.5 ± 1.9 m/sec) at 2 (8.9 ± 1.7 m/sec) and 4 hrs (9.0 ± 1.6 m/sec) post-ingestion in the control group (time × group interaction, P < 0.05). PWV was increased at 2 hrs post-ingestion in the control compared to the exercise trial; 8.9 ± 1.7 vs. 6.2 ± 1.5 m/sec (time × group interaction, P < 0.05). Lipid hydroperoxides increased over time (pooled exercise and control data, P < 0.05). Serum triacylglycerols were elevated postprandially (pooled exercise and control data, P < 0.05). There were no changes in gastric emptying, cholesterol, or C-reactive protein levels. These data suggest that acute exercise prior to the consumption of a high-fat meal has the potential to reduce vascular impairments