Time-Restricted Feeding and Aerobic Performance in Elite Runners: Ramadan Fasting as a Model

A review of the impact of intermittent ramadan fasting on wellbeing, nutrition and physical performance in different sports

BACKGROUND

Athletes in different sports may experience a change in the physical performance during Ramadan Intermittent Fasting (RIF). The impacts of fasting on performance, coping behaviour and fatigue in athletes have not been fully researched.

OBJECTIVE

To examines the effects of Ramadan Intermittent Fasting (RIF) on the physical performance of athletes in different types of sports. The approaches used to assess effects of intermittent fasting among young athletes have not yet been systematically reviewed.

METHOD

Following PRISMA guidelines, 3 independent searches on different databases to identify all the articles describing effects of RIF on physical performance of athletes with all available articles from 2014 up to April 2024.

RESULTS

Among 422 articles identified, 31 studies met eligibility criteria. Fourteen studies reported the effect of Ramadan fasting on individual sports, three studies on combat sports, and fourteen studies on team sports.

CONCLUSION

The RIF negatively effects the physical performance, players coping behavior, nutritional status and fatigue capacities in different sports, although, the negative effects are greater for Handball, Basketball, Volleyball, Football and Swimming although the impact is less negative for Tennis, Badminton, Martial arts and Endurance sports. The athletes who maintain their total energy and macronutrient intake, training load, body composition, sleep length and quality are unlikely to suffer any substantial decrements in performance during Ramadan. Adding other recovery methods could improve performance and reduce the fatigue and muscle soreness experienced with increased game frequency during RIF.

Dietary timing enhances exercise by modulating fat-muscle crosstalk via adipocyte AMPKα2 signaling

Feeding rhythms regulate exercise performance and muscle energy metabolism. However, the mechanisms regulating adipocyte functions remain unclear. Here, using multi-omics analyses, involving (phospho-)proteomics and lipidomics, we found that day-restricted feeding (DRF) regulates diurnal rhythms of the mitochondrial proteome, neutral lipidome, and nutrient-sensing pathways in mouse gonadal white adipose tissue (GWAT). Adipocyte-specific knockdown of Prkaa2 (the gene encoding AMPKα2) impairs physical endurance. This defect is associated with altered rhythmicity in acyl-coenzyme A (CoA) metabolism-related genes, a loss of rhythmicity in the GWAT lipidome, and circadian remodeling of serum metabolites-in particular, lactate and succinate. We also found that adipocyte Prkaa2 regulates muscle clock genes during DRF. Notably, oral administration of the AMPK activator C29 increases endurance and muscle functions in a time-of-day manner, which requires intact adipocyte AMPKα2 signaling. Collectively, our work defines adipocyte AMPKα2 signaling as a critical regulator of circadian metabolic coordination between fat and muscle, thereby enhancing exercise performance.

Effects of intermittent fasting combined with physical exercise on cardiometabolic outcomes: systematic review and meta-analysis of clinical studies

CONTEXT

Different intermittent fasting (IF) protocols have been proven to be efficient in improving cardiometabolic markers, but further research is needed to examine whether or not combining IF regimens plus physical exercise is superior to control diets (ie, nonfasting eating) plus physical exercise in this setting.

OBJECTIVE

The aim of this study was to determine whether or not combining IF plus exercise interventions is more favorable than a control diet plus exercise for improving cardiometabolic health outcomes.

DATA SOURCE

PubMed, Scopus, and Web of Science were comprehensively searched until April 2023.

DATA EXTRACTION

Electronic databases were searched for clinical trials that determined the effect of IF plus exercise vs a control diet plus exercise on body weight, lipid profile (high-density lipoprotein [HDL], low-density lipoprotein [LDL], triglycerides, and total cholesterol), and systolic and diastolic blood pressure (SBP and DBP, respectively). Analyses were conducted for IF plus exercise vs a nonfasting diet plus exercise to calculate weighted mean differences (WMDs).

DATA ANALYSIS

The meta-analysis included a total of 14 studies, with a total sample of 360 adults with or without obesity. The duration ranged from 4 to 52 weeks. IF plus exercise decreased body weight (WMD = -1.83 kg; P = 0.001), LDL (WMD = -5.35 mg/dL; P = 0.03), and SBP (WMD = -2.99 mm Hg; P = 0.003) significantly more than a control diet plus exercise. HDL (WMD = 1.57 mg/dL; P = 0.4) and total cholesterol (WMD = -2.24 mg/dL; P = 0.3) did not change significantly for IF plus exercise vs a control diet plus exercise, but there was a trend for reducing triglycerides (WMD = -13.13 mg/dL; P = 0.07) and DBP (WMD = 2.13 mm Hg; P = 0.05), which shows clinical magnitude.

CONCLUSION

IF plus exercise improved some cardiometabolic outcomes (body weight, blood pressure, and lipid profile) compared with a control diet plus exercise.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO registration no. CRD42023423878.

Daytime-restricted feeding enhances running endurance without prior exercise in mice

Physical endurance and energy conservation are essential for survival in the wild. However, it remains unknown whether and how meal timing regulates physical endurance and muscle diurnal rhythms. Here, we show that day/sleep time-restricted feeding (DRF) enhances running endurance by 100% throughout the circadian cycle in both male and female mice, compared to either ad libitum feeding or night/wake time-restricted feeding. Ablation of the circadian clock in the whole body or the muscle abolished the exercise regulatory effect of DRF. Multi-omics analysis revealed that DRF robustly entrains diurnal rhythms of a mitochondrial oxidative metabolism-centric network, compared to night/wake time-restricted feeding. Remarkably, muscle-specific knockdown of the myocyte lipid droplet protein perilipin-5 completely mimics DRF in enhancing endurance, enhancing oxidative bioenergetics and outputting rhythmicity to circulating energy substrates, including acylcarnitine. Together, our work identifies a potent dietary regimen to enhance running endurance without prior exercise, as well as providing a multi-omics atlas of muscle circadian biology regulated by meal timing.

Efficacy and mechanism of intermittent fasting in metabolic associated fatty liver disease based on ultraperformance liquid chromatography-tandem mass spectrometry

OBJECTIVES

Drug treatment of metabolic associated fatty liver disease (MAFLD) remains lacking. This study analyzes the efficacy and mechanism underlying intermittent fasting combined with lipidomics.

METHODS

Thirty-two male rats were randomly divided into three groups: Normal group, administered a standard diet; MAFLD group, administered a 60% high-fat diet; time-restricted feeding (TRF) group, administered a 60% high-fat diet. Eating was allowed for 6 h per day (16:00-22:00). After 15 weeks, liver lipidomics and other indicators were compared.

RESULTS

A total of 1,062 metabolites were detected. Compared with the Normal group, the weight, body fat ratio, aspartate aminotransferase, total cholesterol, low-density cholesterol, fasting blood glucose, uric acid, and levels of 317 lipids including triglycerides (TG) (17:0-18:1-20:4) were upregulated, whereas the levels of 265 lipids including phosphatidyl ethanolamine (PE) (17:0-20:5) were downregulated in the MAFLD group (P < 0.05). Compared with the MAFLD group, the weight, body fat ratio, daily food intake, and levels of 253 lipids including TG (17:0-18:1-22:5) were lower in the TRF group. Furthermore, the levels of 82 lipids including phosphatidylcholine (PC) (20:4-22:6) were upregulated in the TRF group (P < 0.05), while serum TG level was increased; however, the increase was not significant (P > 0.05). Enrichment analysis of differential metabolites showed that the pathways associated with the observed changes mainly included metabolic pathways, regulation of lipolysis in adipocytes, and fat digestion and absorption, while reverse-transcription polymerase chain reaction showed that TRF improved the abnormal expression of FAS and PPARα genes in the MAFLD group (P < 0.05).

CONCLUSION

Our results suggest that 6 h of TRF can improve MAFLD via reducing food intake by 13% and improving the expression of genes in the PPARα/FAS pathway, thereby providing insights into the prevention and treatment of MAFLD.