A peer support intervention for first-time mothers: Feasibility and preliminary efficacy of the mummy buddy program.

BACKGROUND: The transition to motherhood, although joyous, can be highly stressful, and the availability of professional postpartum support for mothers is often limited. Peer volunteer support programs may offer a viable and cost-effective method to provide community-based support for new mothers. AIM: To determine the feasibility of a peer volunteer support program-The Mummy Buddy Program-in which experienced volunteer mothers are paired with, and trained to offer social support to, first-time mothers. METHODS: Using a single-group non-randomised feasibility trial, a total of 56 experienced mothers participated in the Mummy Buddy training program, which was focused on education and practical exercises relating to the provision of various forms of social support. Experienced mothers ('Mummy Buddies') were subsequently paired with expectant first-time mothers (n=47 pairs), and were encouraged to provide support until 24-weeks postpartum. FINDINGS: In terms of key feasibility considerations, 95.1% of Mummy Buddies felt that they were trained sufficiently to perform their role, and 85.8% of New Mothers were satisfied with the support provided by their Buddy. Analyses of preliminary efficacy (i.e., program outcomes) revealed that the first-time mothers maintained normal levels of stress and depressive symptomology, and possessed relatively strong maternal functioning, across the program duration. CONCLUSION: The Mummy Buddy Program appears to be a feasible and potentially valuable peer volunteer support program for first-time mothers. This study provides a foundation for program expansion and for work designed to examine program outcomes-for first-time mothers, Mummy Buddies, and entire family units-within a sufficiently-powered randomised controlled trial.

Effect of combining pre-exercise carbohydrate intake and repeated short sprints on the blood glucose response to moderate-intensity exercise in young individuals with Type 1 diabetes.

AIMS: To determine whether pre-exercise ingestion of carbohydrates to maintain stable glycaemia during moderate-intensity exercise results in excessive hyperglycaemia if combined with repeated sprints in individuals with Type 1 diabetes. METHODS: Eight overnight-fasted people with Type 1 diabetes completed the following four 40-min exercise sessions on separate days in a randomized counterbalanced order under basal insulinaemic conditions: continuous moderate-intensity exercise at 50% V ˙ O 2 peak; intermittent high-intensity exercise (moderate-intensity exercise interspersed with 4-s sprints every 2 min and a final 10-s sprint); continuous moderate-intensity exercise with prior carbohydrate intake (~10 g per person); and intermittent high-intensity exercise with prior carbohydrate intake. Venous blood was sampled during and 2 h after exercise to measure glucose and lactate levels. RESULTS: The difference in marginal mean time-averaged area under the blood glucose curve between continuous moderate-intensity exercise + prior carbohydrate and intermittent high-intensity exercise + prior carbohydrate during exercise and recovery was not significant [0.2 mmol/l (95% CI -0.7, 1.1); P = 0.635], nor was the difference in peak blood glucose level after adjusting for baseline level [0.2 mmol/l (95% CI -0.7, 1.1); P = 0.695]. The difference in marginal mean time-averaged area under the blood glucose curve between continuous moderate-intensity and intermittent high-intensity exercise during exercise and recovery was also not significant [-0.2 mmol/l (95% CI -1.2, 0.8); P = 0.651]. CONCLUSIONS: When carbohydrates are ingested prior to moderate-intensity exercise, adding repeated sprints is not significantly detrimental to glycaemic management in overnight fasted people with Type 1 diabetes under basal insulin conditions.

The glycaemic benefits of a very-low-carbohydrate ketogenic diet in adults with Type 1 diabetes mellitus may be opposed by increased hypoglycaemia risk and dyslipidaemia.

AIMS: To investigate whether very-low-carbohydrate high-fat diets, typical of ketogenic diets, can improve glycaemic control without causing any ill health effects in adults with Type 1 diabetes. METHODS: In this observational study, 11 adults with Type 1 diabetes (seven men, four women, mean ± sd age 36.1± 6.8 years, mean ± sd duration of diabetes 12.8 ± 10.3 years), who followed a ketogenic diet (< 55 g carbohydrate per day) for a mean ± sd of 2.6 ± 3.3 years (ß-hydroxybutyrate 1.6 ± 1.3 mmol/l), underwent sampling and analysis of fasting blood, and were fitted with a blinded continuous glucose monitor for 7 days to measure glycaemic variability. RESULTS: The mean ± sd HbA1c levels were 35±4 mmol/mol (5.3±0.4%), and participants spent 74±20 and 3±8% of their time in the euglycaemic (4-8 mmol/l) and hyperglycaemic (>10 mmol/l) ranges, respectively, with little daily glycaemic variability (sd 1.5±0.7 mmol/l; coefficient of variation 26±8%). Blood glucose levels were <3.0 mmol/l for 3.6% of the time, and participants experienced a median (range) of 0.9 (0.0-2.0) daily episodes of hypoglycaemia. Total cholesterol, LDL cholesterol, total cholesterol/HDL cholesterol ratio, and triglycerides were above the recommended range in 82%, 82%, 64% and 27% of participants, respectively; however, HDL cholesterol levels were within the recommended range for all participants. Participants displayed no or little evidence of hepatic or renal dysfunction. CONCLUSION: This study provides the first evidence that, ketogenic diets in adults with Type 1 diabetes are associated with excellent HbA1c levels and little glycaemic variability, but may also be associated with dyslipidaemia and a high number of hypoglycaemic episodes.

A 10-second sprint does not blunt hormonal counter-regulation to subsequent hypoglycaemia.

AIM: To investigate whether a 10-second (s) sprint impairs the counter-regulatory response to subsequent hypoglycaemia. METHODS: Nine people (five male, four female) with Type 1 diabetes, aged 21.1 ± 4.5 years, performed a 10-s rest or a 10-s maximum-effort sprint in random order on different days, while subjected to an euinsulinaemic-euglycaemic clamp. This was followed by a hyperinsulinaemic-hypoglycaemic glucose clamp 2.5 h later to induce hypoglycaemia for 40 min. At timed intervals, the counter-regulatory hormonal responses to hypoglycaemia were measured. Blood pressure, heart rate and hypoglycaemic symptoms were also assessed. RESULTS: During the hypoglycaemic clamp, epinephrine, norepinephrine, growth hormone and cortisol levels increased significantly from baseline, and their responses were similar after both rest and sprint conditions. In particular, plasma epinephrine rose eightfold, from 197 ± 103 pmol/l to 1582 ± 1118 pmol/l after the rest condition, and from 219 ± 119 pmol/l to 1900 ± 898 pmol/l after the sprint condition. CONCLUSION: A 10-s sprint is unlikely to blunt the subsequent hormonal counter-regulation to hypoglycaemia in individuals with Type 1 diabetes.

Effect of sodium phosphate supplementation on repeated high-intensity cycling efforts.

Limited research has investigated how sodium phosphate supplementation affects exercise performance typical of athletic competition and whether any effects linger in the short term. This study examined the effect of sodium phosphate supplementation on a cycling protocol consisting of repeated-sprint (4 sets of 6 × 15 s) and time-trial (2 × 5 min) efforts on day 1 and 4 post-loading. Trained male cyclists (VO(2peak) 5.3 L · min⁻¹) were randomised to 6 days of sodium phosphate supplementation (50 mg · kg·fat-free-mass⁻¹ · day⁻¹; n = 7) or placebo (n = 10). Performance was assessed at baseline and 1 and 4 days post-supplementation on an air-braked cycle ergometer. Compared with baseline, the sodium phosphate group recorded significantly improved (P < 0.05) work and mean power output values in both the sprint (baseline, 259 kJ/719 W; day 1, 271 kJ/754 W; day 4, 271 kJ/753 W) and time-trial (baseline, 225 kJ/374 W; day 1, 235 kJ/398 W; day 4, 236 kJ/393 W) aspects of the performance test post-loading. In the placebo group, no differences (P > 0.05) in total work or power output were noted in response to supplementation. In summary, sodium phosphate supplementation improved repeated-sprint and time-trial cycling efforts both 1 and 4 days post-loading in trained cyclists.

Investigation of treadmill and overground running: implications for the measurement of oxygen cost in children with developmental coordination disorder.

Differences in the kinematics and kinetics of overground running have been reported between boys with and without developmental coordination disorder (DCD). This study compared the kinematics of overground and treadmill running in children with and without DCD to determine whether any differences in technique are maintained, as this may influence the outcome of laboratory treadmill studies of running economy in this population. Nine boys with DCD (10.3 ± 1.1 year) and 10 typically developing (TD) controls (9.7 ± 1 year) ran on a treadmill and overground at a matched velocity (8.8 ± 0.9 km/h). Kinematic data of the trunk and lower limb were obtained for both conditions using a 12-camera Vicon MX system. Both groups displayed an increase in stance time (p < 0.001), shorter stride length (p < 0.001), higher cadence (p < 0.001) and reduced ankle plantar flexion immediately after toe-off (p < 0.05) when running on the treadmill compared with overground. The DCD group had longer stance time (p < 0.009) and decreased knee flexion at mid-swing (p = 0.04) while running overground compared to their peers, but these differences were maintained when running on the treadmill. Treadmill running improved ankle joint symmetry in the DCD group compared with running overground (p = 0.019). Overall, these findings suggest that there are limited differences in joint kinematics and lower limb symmetry between overground and treadmill running in this population. Accordingly, laboratory studies of treadmill running in children with DCD are likely representative of the energy demands of running.

High-intensity intermittent exercise attenuates ad-libitum energy intake.

OBJECTIVE: To examine the acute effects of high-intensity intermittent exercise (HIIE) on energy intake, perceptions of appetite and appetite-related hormones in sedentary, overweight men. DESIGN: Seventeen overweight men (body mass index: 27.7±1.6 kg m(-2); body mass: 89.8±10.1 kg; body fat: 30.0±4.3%; VO(2peak): 39.2±4.8 ml kg(-1) min(-1)) completed four 30-min experimental conditions using a randomised counterbalanced design. CON: resting control, MC: continuous moderate-intensity exercise (60% VO(2peak)), HI: high-intensity intermittent exercise (alternating 60 s at 100% VO(2peak) and 240 s at 50% VO(2peak)), VHI: very-high-intensity intermittent exercise (alternating 15 s at 170% VO(2peak) and 60 s at 32% VO(2peak)). Participants consumed a standard caloric meal following exercise/CON and an ad-libitum meal 70 min later. Capillary blood was sampled and perceived appetite assessed at regular time intervals throughout the session. Free-living energy intake and physical activity levels for the experimental day and the day after were also assessed. RESULTS: Ad-libitum energy intake was lower after HI and VHI compared with CON (P=0.038 and P=0.004, respectively), and VHI was also lower than MC (P=0.028). Free-living energy intake in the subsequent 38 h remained less after VHI compared with CON and MC (P≤0.050). These observations were associated with lower active ghrelin (P≤0.050), higher blood lactate (P≤0.014) and higher blood glucose (P≤0.020) after VHI compared with all other trials. Despite higher heart rate and ratings of perceived exertion (RPE) during HI and VHI compared with MC (P≤0.004), ratings of physical activity enjoyment were similar between all the exercise trials (P=0.593). No differences were found in perceived appetite between trials. CONCLUSIONS: High-intensity intermittent exercise suppresses subsequent ad-libitum energy intake in overweight inactive men. This format of exercise was found to be well tolerated in an overweight population.

A comparison of the oxygen cost and physiological responses to running in children with and without Developmental Coordination Disorder.

The aim of this study was to compare the oxygen cost of running in boys with and without Developmental Coordination Disorder (DCD). Fourteen boys with DCD (9.1 ± 1.4 yr) and 16 typically developing (TD) controls (9.4 ± 1.3 yr) were tested on two separate occasions at least a week apart. On the first visit, motor proficiency, body composition and maximal aerobic capacity were established. On the second visit, oxygen consumption was determined via indirect calorimetry while participants ran at three submaximal speeds (7.2 km/h, 8.0 km/h and 8.8 km/h) on a motorised treadmill for 4 min each. Additional physiological responses such as blood lactate, respiratory exchange ratio (RER), heart rate, salivary alpha amylase and pain threshold were monitored at baseline and after each submaximal effort. Although there were no differences in the oxygen cost of running at all three speeds, the boys with DCD had higher blood lactate concentration (7.2 km/h, p=0.05; 8.0 km/h p=0.019), heart rate (p ≤ 0.001), RER (8.0 km/h, p=0.019; 8.8 km/h, p=0.001), salivary alpha amylase (8.0 km/h, p=0.023; 8.8 km/h, p=0.020) and a lower pain threshold (p<0.01). The higher overall metabolic cost of running in boys with DCD as indicated by the higher RER, heart rate and blood lactate concentrations, together with the higher levels of sympathoadrenal medullary activity and sensitivity to pain, may be deterring factors for participation in physical activity in this population.

A comparison of running kinematics and kinetics in children with and without developmental coordination disorder.

The aim of this study was to compare running gait in children with and without developmental coordination disorder (DCD). Fourteen boys with DCD (9.5 ± 1 yr) and 14 typically developing (TD) controls (9.6 ± 1 yr) ran at a velocity of 2.44 ± 0.25 m/s along a 15m track, with kinematic and kinetic data of the trunk and lower limb obtained for three cycles of each limb using a 12-camera Vicon MX system and AMTI force plate. Although features of the kinematic and kinetic trajectories were similar between groups, the DCD group displayed decreased peak knee extension compared with the TD group prior to initial foot contact (p = 0.016). Furthermore, the DCD group displayed increased variability in sagittal plane kinematics at the hip and ankle during toe off compared with the TD group. Kinetic analysis revealed that children with DCD displayed significantly reduced knee extensor moments during the stance phase of the running cycle (p = 0.033). Consequently, peak knee power absorption and ankle power generation was significantly lower in the DCD group (p = 0.041; p = 0.017). Furthermore, there was a trend for children with DCD to have shorter strides (p = 0.052, ES = 0.499) and a longer stance period than the TD controls (p=0.06, ES = 0.729). These differences may have implications for the economy of running and subsequently the planning of targeted intervention programs to improve running gait in children with DCD.

Lower cardiorespiratory fitness in children with Type 1 diabetes.

AIMS: The present study aimed to compare cardiorespiratory fitness levels in children with and without Type 1 diabetes. In addition, the relationship between cardiorespiratory fitness and a range of physical and clinical factors was investigated. METHODS: Eighty-eight children with Type 1 diabetes aged 5-14 years completed a submaximal step test of cardiorespiratory fitness. Sixty-two of these children were successfully matched to control subjects without diabetes based on age, sex and anthropometrics for comparison. In addition, the relationship between cardiorespiratory fitness and a range of physical and clinical variables was assessed in the children with diabetes. RESULTS: The heart rate response to exercise was higher in children with Type 1 diabetes, indicating reduced cardiorespiratory fitness levels compared with control subjects. Both gender and glycaemic control (HbA(1c) ) were significantly associated with cardiorespiratory fitness, with female sex and poorer glycaemic control associated with reduced fitness. CONCLUSIONS: Future research should investigate whether the reduced fitness in children with Type 1 diabetes is attributable to lower physical activity levels, or physiological changes resulting from the diabetes pathology itself.

Effect of a carbohydrate mouth rinse on maximal sprint performance in competitive male cyclists.

There is evidence that rinsing the mouth with a carbohydrate (CHO) solution can improve endurance performance. The goal of this study was to investigate whether a CHO mouth rinse can improve the performance of a maximal sprint effort. Fourteen competitive male cyclists (64.0±5.6 mL kg(-1) min(-1) (mean±SD)) each completed the following 5-s mouth rinse trials in a randomised counter-balanced order; (a) 6.4% maltodextrin solution [Mal], (b) 7.1% glucose solution [Glu], (c) water [Wa] and (d) a control trial with no rinse [Con]. Each participant then performed a 30-s maximal sprint effort on a cycle ergometer. Glu, Mal and Wa trials were not significantly different from Con across all indicators of sprint performance (maximal power output, mean power output over 0-30, 0-10, 10-20, and 20-30s), nausea or fatigue level (p>0.05). These findings suggest that the use of a 5-s mouth rinse with an isoenergetic amount of either maltodextrin or glucose is not beneficial for maximal sprint performance.

Supervised home-based exercise may attenuate the decline of glucose tolerance in obese pregnant women.

AIM: The significant deterioration of insulin sensitivity and glucose tolerance during pregnancy can have serious health implications for both the pregnant woman and her baby. Although it is well established that regular exercise benefits insulin sensitivity in the nonpregnant population, the effect on glucose tolerance in obese pregnant women is not known. The purpose of this study was to investigate the effect of a supervised 10-week, home-based, exercise programme, beginning at week 18 of gestation, on glucose tolerance and aerobic fitness in previously sedentary obese women. METHODS: Twelve sedentary obese women were randomized into an exercise (EX; n=6) or control (CON; n=6) group at 18 weeks of gestation. Those randomized to EX engaged in 10 weeks of supervised home-based exercise (three sessions a week of stationary cycling), while those in the CON group maintained their usual daily activity. Their glucose and insulin responses to an oral glucose tolerance test (OGTT), as well as their aerobic fitness, were assessed both pre- and postintervention. RESULTS: Reduced glucose tolerance in the CON, but not EX, group was indicated by a tendency postintervention towards higher blood glucose levels at 1h of the OGTT (P=0.072). Furthermore, at 2h of the postintervention OGTT, blood glucose tended to remain elevated from baseline in the CON (P=0.077). There was also a trend towards increased fitness in the EX (P=0.064), but not the CON group. CONCLUSION: Regular aerobic exercise begun during pregnancy may have favourable effects on glucose tolerance and fitness in obese women, and warrants further investigation in a larger sample population.

Effect of intermittent high-intensity compared with continuous moderate exercise on glucose production and utilization in individuals with type 1 diabetes.

Previously, the decline in glycemia in individuals with type 1 diabetes has been shown to be less with intermittent high-intensity exercise (IHE) compared with continuous moderate-intensity exercise (MOD) despite the performance of a greater amount of total work. The purpose of the present study was to determine whether this lesser decline in glycemia can be attributed to a greater increment in endogenous glucose production (Ra) or attenuated glucose utilization (Rd). Nine individuals with type 1 diabetes were tested on two separate occasions, during which either a 30-min MOD or IHE protocol was performed under conditions of a euglycemic clamp in combination with the infusion of [6,6-(2)H]glucose. MOD consisted of continuous cycling at 40% VO2 peak, whereas IHE involved a combination of continuous exercise at 40% VO2 peak interspersed with additional 4-s maximal sprint efforts performed every 2 min to simulate the activity patterns of intermittent sports. During IHE, glucose Ra increased earlier and to a greater extent compared with MOD. Similarly, glucose Rd increased sooner during IHE, but the increase by the end of exercise was comparable with that elicited by MOD. During early recovery from IHE, Rd rapidly declined, whereas it remained elevated after MOD, a finding consistent with a lower glucose infusion rate during early recovery from IHE compared with MOD (P<0.05). The results suggest that the lesser decline in glycemia with IHE may be attributed to a greater increment in Ra during exercise and attenuated Rd during exercise and early recovery.