Background/Objectives: Sports performance is influenced by a complex interplay of physical, physiological, and psychological factors, which differ across disciplines. Thus, this study aims to identify and compare the distinct multidimensional profiles (i.e., body composition, diet, resting metabolic rate, physical activity, sleep quality, and subjective well-being) of athletes from different sports disciplines (i.e., endurance, strength, and intermittent sports). Methods: This study included 77 athletes (28 women) classified as endurance (n = 40), strength (n = 12), or intermittent (n = 25). Body composition was assessed by dual-energy X-ray absorptiometry, bioimpedance, and anthropometry, diet was determined using dietary recalls, resting metabolic rate was assessed by indirect calorimetry, physical activity and sleep quality were determined by a wrist-worn accelerometer, and subjective well-being was determined through validated questionnaires. Results: Strength and intermittent athletes had greater body weight, lean mass, and bone parameters than endurance athletes, whereas intermittent athletes showed higher adiposity than endurance levels (all p ≤ 0.008). The endurance group did not exhibit a higher intake of fats or proteins compared to the strength and intermittent groups; however, it did demonstrate a higher consumption of carbohydrates (p ≤ 0.016). No differences were observed in resting metabolic rate, sleep quality, and subjective well-being, though endurance athletes demonstrated higher levels of vigorous physical activity than strength athletes (p = 0.014). Conclusions: In conclusion, we reveal a distinct physiological phenotype between strength, intermittent, and endurance athletes in terms of body composition, dietary intake, and physical activity levels. These findings underscore the necessity for tailored training and nutrition protocols depending on the sports discipline.

Introduction Metabolic dysfunction-associated steatotic liver disease is a major public health problem considering its high prevalence and its strong association with extrahepatic diseases. Implementing strategies based on an intermittent fasting approach and supervised exercise may mitigate the risks. This study aims to investigate the effects of a 12-week time-restricted eating (TRE) intervention combined with a supervised exercise intervention, compared with TRE or supervised exercise alone and with a usual-care control group, on hepatic fat (primary outcome) and cardiometabolic health (secondary outcomes) in adults with obesity. Methods and analysis An anticipated 184 adults with obesity (50% women) will be recruited from Granada (south of Spain) for this parallel-group, randomised controlled trial (TEMPUS). Participants will be randomly designated to usual care, TRE alone, supervised exercise alone or TRE combined with supervised exercise, using a parallel design with a 1:1:1:1 allocation ratio. The TRE and TRE combined with supervised exercise groups will select an 8-hour eating window before the intervention and will maintain it over the intervention. The exercise alone and TRE combined with exercise groups will perform 24 sessions (2 sessions per week+walking intervention) of supervised exercise combining resistance and aerobic high-intensity interval training. All participants will receive nutritional counselling throughout the intervention. The primary outcome is change from baseline to 12 weeks in hepatic fat; secondary outcomes include measures of cardiometabolic health. Ethics and dissemination This study was approved by Granada Provincial Research Ethics Committee (CEI Granada—0365-N-23). All participants will be asked to provide written informed consent. The findings will be disseminated in scientific journals and at international scientific conferences. Trial registration number NCT05897073.

Context: Intermuscular adipose tissue (IMAT) at different anatomical locations may exert distinct effects on cardiometabolic risk. Objective: The present study investigated the relationships of abdominal and mid-thigh IMAT with glucose homeostasis and cardiometabolic risk in adults with overweight or obesity. Design: Multicenter cross-sectional study. Setting: Outpatient clinic. Participants: One hundred eighty-nine adults (50% women; age: 46.8 ± 6.3 years) with overweight or obesity (body mass index: 32.9 ± 3.5 kg/m2). Main Outcome Measures: IMAT content in abdominal and mid-thigh regions was measured by magnetic resonance imaging. Mean glucose levels were monitored over 24 hours during 14 days using continuous glucose monitoring devices. We computed a cardiometabolic risk score including fasting high-density lipoprotein cholesterol, triglycerides, glucose, waist circumference, and systolic and diastolic blood pressure. Results: No associations were identified between abdominal IMAT and glucose homeostasis or cardiometabolic risk (all P > .05). In contrast, a positive association of mid-thigh IMAT with 24-hour (β = 0.226; P = .007), diurnal (β = 0.224; P = .008), and nocturnal mean glucose levels (β = 0.233; P = .006) as well as with cardiometabolic risk score (β = 0.324; P < .001) was observed. Participants with greater accumulation of IMAT in the mid-thigh compared to the abdominal region exhibited significantly higher mean glucose levels and cardiometabolic risk (all P < .005). Conclusion: These findings emphasize the importance of distinguishing between adipose tissue depots when evaluating cardiometabolic risk, as specific accumulation patterns—particularly in the mid-thigh region—may significantly influence individual risk profiles.

The optimal eating window for time-restricted eating (TRE) remains unclear. We investigated the effects of 8-hour TRE combined with usual care (UC, a Mediterranean diet-based education program), versus UC alone over 12 weeks on hepatic fat fraction, liver health markers, and fecal microbiota in adults with overweight or obesity. In this multicenter randomized trial, participants (50% women) were assigned to UC (n=49), early TRE (n=49), late TRE (n=52), or self-selected TRE (n=47). Hepatic fat fraction was assessed by MRI; liver markers included elastography-based parameters, liver enzymes, and circulating biomarkers. Fecal microbiota was analyzed by 16S rRNA gene sequencing. Hepatic fat fraction decreased significantly within the three TRE groups (all P≤0.02), but no between-group differences were observed when comparing early TRE (mean difference [MD]: -0.4%; P=0.95), late TRE (MD: -1.5%; P=0.15), and self-selected TRE groups (MD: -0.7%; P=0.77) with the UC group, or among the TRE groups themselves (all P≥0.41). Similarly, no between-group differences were found in liver health markers and fecal microbiota. Participants with metabolic dysfunction-associated steatotic liver disease at baseline as well as those achieving ≥5% weight loss had greater reductions in hepatic fat fraction than those who did not (MD: -2.7 and -2.6%; respectively, both P<0.001). A higher proportion of participants in the TRE groups achieved ≥5% weight loss compared with UC (41-44% vs 16%; P=0.001). These findings suggest that the timing of the eating window in TRE may not impact hepatic fat fraction or microbiota composition beyond the effects of weight loss, though the study was not powered for secondary outcomes. The study was registered on ClinicalTrials.gov (identifier: NCT05310721). NCT05310721 IMPACT AND IMPLICATIONS: Time-restricted eating (TRE) is increasingly used for obesity management, but whether the timing of the eating window influences liver health remains unclear. In this 12-week multicenter randomized trial, adding early, late, or self-selected 8-hour TRE to Mediterranean diet-based usual care led to within-group reductions in MRI-assessed hepatic fat fraction, but did not confer greater improvements in hepatic fat fraction, liver health markers, or fecal microbiota than usual care alone. Participants with baseline metabolic dysfunction-associated steatotic liver disease (MASLD) and those achieving ≥5% weight loss experienced larger reductions in hepatic fat fraction, suggesting these reductions in this context are more closely linked to weight loss and baseline steatosis than to eating-window timing. Clinically, these findings support prioritizing feasible eating schedules and strategies that help patients attain clinically meaningful weight loss, particularly among individuals with MASLD.

Background/Objectives: Energy availability (EA), defined as the dietary energy remaining after exercise energy expenditure (EEE), is a central determinant of both health and performance in athletes. Chronic insufficient EA leads to low energy availability (LEA), which is an underlying mechanism of Relative Energy Deficiency in Sport (REDs). This narrative review critically explores the conceptual evolution of EA and LEA, summarizes current physiological evidence, and discusses methodological and practical challenges in their assessment and application in free-living athletes. Methods: Evidence from experimental and observational studies was reviewed to describe the hormonal, metabolic, and performance outcomes associated with LEA. Screening tools, including the Low Energy Availability in Females Questionnaire (LEAF-Q) and the Low Energy Availability in Males Questionnaire (LEAM-Q), were also evaluated for their validity and applicability in different sports contexts. Results: LEA is associated with alterations in thyroid and reproductive hormones, which, in turn, contribute to reduced resting metabolic rate, lower bone mineral density, and delayed recovery. While screening questionnaires can help identify athletes at risk, their accuracy varies by sport and individual characteristics. Incorporating hormonal and metabolic biomarkers provides a more direct and sensitive method for detecting physiological stress. Measuring dietary intake, EEE, endocrine balance and body composition in real-world settings remains a major methodological challenge. Combining hormonal, metabolic, and behavioral indicators may improve the identification of athletes experiencing LEA. Conclusions: EA plays a central role in the interaction between nutrition, exercise, and athlete health, but methodological limitations in its assessment may compromise accurate diagnosis. Improving measurement techniques and adopting integrated monitoring strategies are essential to improve early detection, guide individualized nutrition, and prevent RED-related health and performance impairments.