Metabolic characteristics of keto-adapted ultra-endurance runners

Background: Many successful ultra-endurance athletes have switched from a high-carbohydrate to a low-carbohydrate diet, but they have not previously been studied to determine the extent of metabolic adaptations. Methods: Twenty elite ultra-marathoners and ironman distance triathletes performed a maximal graded exercise test and a 180 min submaximal run at 64% VO2max on a treadmill to determine metabolic responses. One group habitually consumed a traditional high-carbohydrate (HC: n = 10, %carbohydrate:protein:fat = 59:14:25) diet, and the other a low-carbohydrate (LC; n = 10, 10:19:70) diet for an average of 20 months (range 9 to 36 months). Results: Peak fat oxidation was 2.3-fold higher in the LC group (1.54 ± 0.18 vs 0.67 ± 0.14 g/min; P = 0.000) and it occurred at a higher percentage of VO2max (70.3 ± 6.3 vs 54.9 ± 7.8%; P = 0.000). Mean fat oxidation during submaximal exercise was 59% higher in the LC group (1.21 ± 0.02 vs 0.76 ± 0.11 g/min; P = 0.000) corresponding to a greater relative contribution of fat (88 ± 2 vs 56 ± 8%; P = 0.000). Despite these marked differences in fuel use between LC and HC athletes, there were no significant differences in resting muscle glycogen and the level of depletion after 180 min of running (− 64% from pre-exercise) and 120 min of recovery (− 36% from pre-exercise). Conclusion: Compared to highly trained ultra-endurance athletes consuming an HC diet, long-term keto-adaptation results in extraordinarily high rates of fat oxidation, whereas muscle glycogen utilization and repletion patterns during and after a 3 hour run are similar

‘Perceptions of non-accidental child deaths as preventable events: The impact of probability heuristics and biases on child protection work'

Anxiety about the possibility of non-accidental deaths of children has had a major influence on child care policy and practice over the last 40 years. The formal inquiry reports and media coverage of these rare events serve to maintain the perception that these are regular incidents that happen far too often and that they could have been prevented. This focus on individual events tends to distort a clear view of the actual probability of non-accidental deaths and serves to reinforce the notion that potentially all child care cases are risky and that any social work practitioner could be involved in such a case. As a result, work with children has become highly risk averse. However, in statistical terms, the probability of non-accidental child deaths is very low and recently has averaged about 55 deaths a year. Children are at considerably higher risk of being killed on the roads. This paper examines the way in which perceptions of the ‘high’ level of risk of possible child deaths are maintained despite the very low statistical probability of such incidents. It draws on thinking from behavioural psychology and, in particular the work of Kahneman and Tversky, to consider some of the biases in probability reasoning affecting people’s perception of risk and explores how inquiry reports into single past events reconfirm risk perceptions. It is suggested that recognition of the essentially unpredictable nature of future non-accidental child deaths would free up childcare professionals to work in a more positive and less risk-averse manner in the present

‘Perceptions of non-accidental child deaths as preventable events: The impact of probability heuristics and biases on child protection work'

Anxiety about the possibility of non-accidental deaths of children has had a major influence on child care policy and practice over the last 40 years. The formal inquiry reports and media coverage of these rare events serve to maintain the perception that these are regular incidents that happen far too often and that they could have been prevented. This focus on individual events tends to distort a clear view of the actual probability of non-accidental deaths and serves to reinforce the notion that potentially all child care cases are risky and that any social work practitioner could be involved in such a case. As a result, work with children has become highly risk averse. However, in statistical terms, the probability of non-accidental child deaths is very low and recently has averaged about 55 deaths a year. Children are at considerably higher risk of being killed on the roads. This paper examines the way in which perceptions of the ‘high’ level of risk of possible child deaths are maintained despite the very low statistical probability of such incidents. It draws on thinking from behavioural psychology and, in particular the work of Kahneman and Tversky, to consider some of the biases in probability reasoning affecting people’s perception of risk and explores how inquiry reports into single past events reconfirm risk perceptions. It is suggested that recognition of the essentially unpredictable nature of future non-accidental child deaths would free up childcare professionals to work in a more positive and less risk-averse manner in the present

The Influence of Resistance Training on Primary Hemostatic Responses

Objective: The rise in casualties of acute cardio vascular disease has increased the investigation of potential ways to combat these problems. Long term resistance training has been viewed as one possible approach in helping to reduce the hyperaggragability of platelets following acute strenuous exercise. The present investigation was designed to explore the effects of an acute resistance exercise test (AERET) and recovery on the primary hemostatic system in both resistance trained and untrained individuals.Methods: Ten resistance trained (RT) (Age, 26.0 ± 1.42 yr; Height, 175.12 ± 2.7 cm; Weight, 79.56 ± 4.29 kg) and ten untrained individuals UT (Age, 26.4 ± 1.97 yr; Height, 170.31 ± 2.36 cm; Weight, 67.88 ± 5.34 kg) performed an AERET (6 sets of 10 repetitions of heavy squats). Blood samples were obtained before exercise, immediately post and at 15, 60 and 120 minutes following the exercise test. Blood samples were analyzed for platelet count, von Willebrand Factor (vWF), Beta Thromboglobulin (β-TG) and Platelet Factor 4 (PF4).Results: Results found significant differences between the RT group and the UT group for measurements of plasma β-TG. Platelet count, vWF and β-TG all increased significantly following the resistance exercise test. PF4 had no significant change. All measured variables returned to baseline 120 minutes following exercise. Conclusion: RT individuals demonstrated reduced platelet activation in vivo in response to an acute bout of heavy resistance exercise compared to UT individuals. Reduced platelet activation could be attributed to training status as shown by reduction in plasma levels of β-TG measured in the RT group

Effects of a Chronic Low Carbohydrate High Fat Diet on Markers of Cholesterol and Lipoprotein Metabolism in Elite Level Ultra-endurance Male Runners

Archival abstract submitted

First Light for Station V of the Low-Frequency All-Sky Monitor Radio Telescope

—The Low-Frequency All-Sky Monitor is a radio telescope network consisting of five stations, each with 13 LongWavelength Array (LWA) antennas, distributed around the North American continent. The LWA antennas are arranged so as to form a wide-angle drift scan beam, sensitive to bright radio transients, astrophysical and ionospheric, at 10–88 MHz. The multiple stations can reliably verify astrophysical events by simultaneous detection. Adding the fifth station at Hillsdale College in Hillsdale, MI, provides a wider range of declination coverage for the project. Station V, like the previous four stations, was constructed by undergraduate researchers, who continue to operate and manage the telescope. Here we report on Station V’s “first light”, and discuss future prospects

Distinct Luminal-Type Mammary Carcinomas Arise from Orthotopic Trp53

Age and physiological status, like menopause, are risk factors for breast cancer. Less clear is what factors influence the diversity of breast cancer. In this study, we investigated the effect of host age on the distribution of tumor subtypes in mouse mammary chimera consisting of wild-type hosts and Trp53 nullizygous epithelium, which undergoes a high rate of neoplastic transformation. Wild-type mammary glands cleared of endogenous epithelium at 3 weeks of age were subsequently implanted during puberty (5 weeks) or at maturation (10 weeks) with syngeneic Trp53 null mammary tissue fragments and monitored for 1 year. Tumors arose sooner from adult hosts (AH) compared to juvenile hosts (JH). However, compared to AH tumors, JH tumors grew several times faster, were more perfused, exhibited a 2-fold higher mitotic index and were more highly positive for insulin-like growth factor receptor phosphorylation. Most tumors in each setting were ER positive (80% JH vs 70% AH) but JH tumors were significantly more ER immunoreactive (p=0.0001) than AH tumors. A differential expression signature (JvA) of juvenile versus adult tumors revealed a luminal transcriptional program. Centroids of the human homologs of JvA genes showed that JH tumors were more like luminal A tumors and AH tumors were more like luminal B tumors. Hierarchical clustering with the JvA human ortholog gene list segregated luminal A and luminal B breast cancers across data sets. These data support the notion that age-associated host physiology greatly influences the intrinsic subtype of breast cancer

Effects of Fatigue from Resistance Training on Barbell Back Squat Biomechanics

Exhaustive resistance training programs that have been previously referred to as extreme conditioning protocols have increased in popularity in military and civilian populations in recent years. However, because of their highly fatiguing nature, proprioception is likely altered during such programs that would significantly affect the safety and efficacy of such programs. Therefore, the purpose of this study was to assess the alterations in movement patterns that result from extreme conditioning protocols and to evaluate if these protocols can be deemed safe and effective. Twelve men (age 24 ± 4.2 years, height 173.1 ± 3.6 cm, weight 76.9 ± 7.8 kg, body fat percentage 9.0 ± 2.2%) and 13 women (age 24.5 ± 3.8 years, height 166.9 ± 8.5 cm, weight 66.1 ± 9.2 kg, body fat percentage 18.6 ± 4.0%) with at least 6 months of resistance training experience involving barbell bench press, barbell deadlift, and barbell back squat performed a highly fatiguing resistance training workout. During the barbell back squat, a 2-dimensional analysis was performed where the knee and hip angles were recorded throughout the 55 repetitions of the workout. At the early stages of the protocol, knee angle was significantly lower in men and in women demonstrating less knee flexion. Also, hip angle was significantly lower early in the program in men and in women, demonstrating a greater forward lean. The technique changes that occur in high repetition sets do not favor optimal strength development and may increase the risk of injury, clearly questioning the safety and efficacy of such resistance training programming. This is likely a display of self-preservation by individuals who are faced with high repetition programs