Publications by authors named "Karsten Koehler"

Background: The global prevalence of the metabolic disease Type 2 Diabetes (T2D) is increasing. Risk factors contributing to the development of T2D include overweight and obesity, lack of physical activity (PA), and an unhealthy diet. In addition, the gut microbiota has been shown to affect metabolic regulation.

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Background: Predicting individual weight loss (WL) responses to lifestyle interventions is challenging but might help practitioners and clinicians select the most promising approach for each individual.

Objective: The primary aim of this study was to develop machine learning (ML) models to predict individual WL responses using only variables known before starting the intervention. In addition, we used ML to identify pre-intervention variables influencing the individual WL response.

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Objective: This cross-sectional study aimed to investigate the role of low energy availability (LEA) in the interplay between depression and disordered eating/eating disorders (DE/EDs) among female athletes. The International Olympic Committee consensus statement on Relative Energy Deficiency in Sport (REDs) identified depression as both an outcome of LEA and a secondary risk factor for REDs. However, the direct link between LEA and depression has yet to be fully established.

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Aim: A 15-s all-out sprint cycle test (i.e., νLa-test) and the post-exercise change in capillary blood lactate concentration is an emerging diagnostic tool that is used to quantify the maximal glycolytic rate.

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Based on Mader's mathematical model, the rate of capillary blood lactate concentration (νLa) following intense exercise is thought to reflect the maximal glycolytic rate. We aimed to investigate the reliability of important variables of Mader's model (i.e.

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Introduction: Evidence indicates that sphingolipid accumulation drives complex molecular alterations promoting cardiometabolic diseases. Clinically, it was shown that sphingolipids predict cardiometabolic risk independently of and beyond traditional biomarkers such as low-density lipoprotein cholesterol. To date, little is known about therapeutic modalities to lower sphingolipid levels.

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Background: Accurate dietary assessment remains a challenge, particularly in free-living settings. Continuous glucose monitoring (CGM) shows promise in optimizing the assessment and monitoring of ingestive activity (IA, i.e.

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Article Synopsis
  • The study aimed to investigate how nitrogen isotope ratios (δN) in urinary urea change during a short-term energy deficit, particularly in physically active individuals.
  • Six active men participated in a controlled experiment that compared their δN during four different energy conditions—two with exercise and two without.
  • Results showed that δN significantly increased during energy deficit with exercise and highlighted the body's response to energy deprivation through amino acid oxidation.
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Unlabelled: Female endurance athletes are at high risk for developing Relative Energy Deficiency in Sport (REDs), resulting in symptoms such as menstrual dysfunction and gastrointestinal (GI) problems. The primary aim of this study was to investigate effects of the FUEL (Food and nUtrition for Endurance athletes-a Learning program) intervention consisting of weekly online lectures combined with individual athlete-centered nutrition counseling every other week for sixteen weeks on REDs related symptoms in female endurance athletes at risk of low energy availability [Low Energy Availability in Females Questionnaire (LEAF-Q) score ≥8]. Female endurance athletes from Norway (= 60), Sweden (= 84), Ireland (= 17), and Germany (= 47) were recruited.

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Article Synopsis
  • Relative Energy Deficiency in Sport (REDs) is a widespread issue among athletes due to low energy availability (LEA), posing serious health risks and performance declines.
  • Prevention strategies include primary measures like education to reduce harmful behaviors related to LEA, secondary measures for early detection of REDs symptoms, and tertiary treatment to address severe consequences.
  • Best practices involve a comprehensive approach involving the athlete's support system, including coaches and sports organizations, to create a safe environment and promote awareness about REDs.
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The Constrained Model of Total Energy Expenditure predicts that increased physical activity may not influence total energy expenditure, but instead, induces compensatory energetic savings in other processes. Much remains unknown, however, about concepts of energy expenditure, constraint and compensation in different populations, and it is unclear whether this model applies to endurance athletes, who expend very large amounts of energy during training and competition. Furthermore, it is well-established that some endurance athletes consciously or unconsciously fail to meet their energy requirements via adequate food intake, thus exacerbating the extent of energetic stress that they experience.

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Growing scientific evidence indicates that sphingolipids predict cardiometabolic risk, independently of and beyond traditional biomarkers such as low-density lipoprotein cholesterol. To date, it remains largely unknown if and how exercise, a simple, low-cost, and patient-empowering modality to optimise cardiometabolic health, influences sphingolipid levels. The SphingoHIIT study aims to assess the response of circulating sphingolipid species to a single session of high-intensity interval training (HIIT).

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When less energy is available to consume, people often lose weight, which reduces their overall metabolic rate. Their cellular metabolic rate may also decrease (metabolic adaptation), possibly reflected in physiological and/or endocrinological changes. Reduced energy availability can result from calorie restriction or increased activity energy expenditure, raising the following question that our review explores: do the body's metabolic and physiological responses to this reduction differ or not depending on whether they are induced by dietary restriction or increased activity? First, human studies offer indirect, contentious evidence that the body metabolically adapts to reduced energy availability, both in response to either a calorie intake deficit or increased activity (exercise; without a concomitant increase in food intake).

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An elevated core temperature (core) increases the risk of performance impairments and heat-related illness. Internal cooling (IC) has the potential to lower core when exercising in the heat. The aim of the review was to systematically analyze the effects of IC on performance, physiological, and perceptional parameters.

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Female endurance athletes are considered a high-risk group for developing Relative Energy Deficiency in Sport (REDs). Due to the lack of educational and behavioral intervention studies, targeting and evaluating the effects of the practical daily management of REDs, we developed the Food and nUtrition for Endurance athletes-a Learning (FUEL) program, consisting of 16 weekly online lectures and individual athlete-centered nutrition counseling every other week. We recruited female endurance athletes from Norway ( = 60), Sweden ( = 84), Ireland ( = 17), and Germany ( = 47).

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Energy intake in the post-exercise state is highly variable and compensatory eating - i.e., (over-) compensation of the expended energy via increased post-exercise energy intake - occurs in some individuals but not others.

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Purpose: Wheelchair athletes experience a reduction in fat-free mass due to the underlying condition and/or muscle disuse. This leads to a lower resting energy expenditure (REE), as well as a lower energy expenditure during exercise or daily activities. Traditional markers of low energy availability (LEA), including amenorrhea and low bone mineral density, are often inconclusive in wheelchair athletes.

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Relative energy deficiency in sport (RED-S) is a complex syndrome describing health and performance consequences of low energy availability (LEA) and is common among female endurance athletes. Various underlying causes of LEA have been reported, including disordered eating behavior (DE), but studies investigating the association with exercise addiction and food intolerances are lacking. Therefore, the aim of this cross-sectional study was to investigate the association between DE, exercise addiction and food intolerances in athletes at risk of LEA compared to those with low risk.

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Article Synopsis
  • - Elite rowers have high energy needs due to their large body size, intense training, and metabolic capacity, leading to significant total energy requirements (TER) impacting performance.
  • - A study measuring exercise energy expenditure (EEE) and substrate utilization (SU) during different rowing intensities found that EEE ranges from 15.6 to 49.8 kcal/min, primarily using carbohydrates for energy even at lower intensities.
  • - Estimated TER for rowers varies by training phase, with high-volume weeks at approximately 6,775 kcal/day, indicating a need for careful nutritional planning to maintain energy availability and support training intensity and overall health.
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Objective: To characterize the contributions of the loss of energy-expending tissues and metabolic adaptations to the reduction in resting metabolic rate (RMR) following weight loss.

Methods: A secondary analysis was conducted on data from the Comprehensive Assessment of Long-term Effects of Reducing Intake of Energy study. Changes in RMR, body composition, and metabolic hormones were examined over 12 months of calorie restriction in 109 individuals.

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The effect of physical activity and exercise on hunger and satiety has been well-studied in younger adults, but the influence of aging is less understood. While some evidence suggests that acute bouts of exercise induce a compensatory eating drive, long-term activity may improve satiety sensitivity. The objective of this study was to investigate the effects of exercise on appetite in older adults.

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Sirtuins are nicotinamide adenine dinucleotide (NAD+)-dependent deacetylases that regulate numerous pathways such as mitochondrial energy metabolism in the human body. Lower levels of these enzymes were linked to diseases such as diabetes mellitus and were also described as a result of aging. Sirtuins were previously shown to be under the control of exercise and diet, which are modifiable lifestyle factors.

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Short-term energy deficits impair anabolic hormones and muscle protein synthesis. However, the effects of prolonged energy deficits on resistance training (RT) outcomes remain unexplored. Thus, we conducted a systematic review of PubMed and SportDiscus for randomized controlled trials performing RT in an energy deficit (RT+ED) for ≥3 weeks.

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