Francisco José Amaro-Gahete

University of Granada | UGR · Department of Physiology

Over the past two decades, scientists have attempted to evaluate whether the point of maximal fat oxidation (FATmax) and the aerobic threshold (AerT) are connected. The existence of such a relationship would allow a more tailored training approach for athletes while improving the efficacy of individualized exercise prescriptions when treating numer...

Purpose This study aimed to investigate the influence of different exercise training modalities on heart rate variability (HRV) in sedentary middle-aged adults; and to study whether changes in health-related outcomes (i.e., body composition and cardiometabolic risk) are associated with those hypothetical HRV changes in sedentary middle-aged adults....

Aim Oral caffeine intake has been deemed as an effective supplementation strategy to enhance fat oxidation during aerobic exercise with a steady-state intensity. However, in real exercise scenarios, individuals habitually train with autoregulation of exercise intensity. This study aimed to analyze the effect of oral caffeine intake during self-pace...

Background Both exercise and polypills are recommended treatments to improve the blood-lipid profile.Objective The aim of this study was to compare head-to-head the effectiveness of polypill and exercise strategies in improving the blood-lipid profile in high-risk cardiovascular patients.Methods We performed an electronic search in Web of Science,...

α-Klotho protein is a powerful predictor of the aging process and lifespan. Although lowered circulating soluble α-Klotho levels have been observed in aged non-healthy individuals, no specific reference values across a wide range of ages and sex using an enzyme-linked immunosorbent assay (ELISA) are available for larger cohorts of healthy individua...

Importance: Obesity is the leading cause of obstructive sleep apnea (OSA); however, the effects of weight loss and lifestyle interventions on OSA and comorbidities remain uncertain. Objective: To evaluate the effect of an interdisciplinary weight loss and lifestyle intervention on OSA and comorbidities among adults with moderate to severe OSA an...

Maximal fat oxidation during exercise (MFO) and the intensity that elicits MFO (Fatmax) seems to show a diurnal variation in men, which favors an increased performance in the afternoon than the morning. At present, it remains unknown whether the observed MFO and Fatmax diurnal variation in men is also present in women. Therefore, the current study...

Background: The family environment influences food consumption and behaviours, which impact adolescent's eating habits, diet and health. Young individuals who frequently eat family meals are less likely to develop risk- and behaviour-related outcomes as obesity. Aim: To assess the relationship between the family meal environment and food and mac...

The maximal fat oxidation rate (MFO) assessed during a graded exercise test is a remarkable physiological indicator associated with metabolic flexibility, body weight loss and endurance performance. The present review considers existing biomarkers related to MFO, highlighting the validity of maximal oxygen uptake and free fatty acid availability fo...

This study aimed to investigate the effects of different exercise training programs on fasting plasma levels of oxylipins, endocannabinoids (eCBs), and eCBs-like molecules in middle-aged sedentary adults. A 12-week randomized controlled trial was conducted using a parallel group design. Sixty-five middle-aged adults (40–65 years old) were randomly...

Background: The ageing process can be influenced by energy intake and different macronutrients within the diet. The soluble form of the α-Klotho gene (called S-Klotho) is widely considered as a powerful anti-ageing biomarker. Objective: To analyze the association of energy, dietary energy density and macronutrient intake with S-Klotho plasma lev...

Bicycle touring as a modality of physical activity that involves whole-body cardiorespiratory and metabolic functions could be a potential strategy to improve body composition and cardiorespiratory fitness. Therefore, the aim of the current study was to investigate the effects of 7-days bicycle touring activity on body composition and physical fitn...

The present study investigates the effect of an acute intake of caffeine on the diurnal variation of neuromuscular performance in resistance-trained women. A total of 15 resistance-trained women participated in the current triple-blind, placebo-controlled, crossover experimental study. We assessed neuromuscular performance (i.e., ballistic (counter...

Background It is important for sport scientists and health professionals to have estimative methods for energy demand during different physical activities. The metabolic equivalent of task (MET) provides a feasible approach for classifying activity intensity as a multiple of the resting metabolic rate (RMR). RMR is generally assumed to be 3.5 mL of...

Background There is evidence that caffeine increases the maximal fat oxidation rate (MFO) and aerobic capacity, which are known to be lower in the morning than in the afternoon. This paper examines the effect of caffeine intake on the diurnal variation of MFO during a graded exercise test in active men. Methods Using a triple-blind, placebo-contro...

The attainment of high inter-day reliability is crucial to determine changes in resting metabolic rate (RMR), respiratory exchange ratio (RER), maximal fat oxidation during exercise (MFO) and the intensity that elicits MFO (Fatmax) after an intervention. This study aimed to analyze the inter-day reliability of RMR, RER, MFO and Fatmax in healthy ad...

Background Vitamin D deficiency is currently endemic worldwide and is considered as an important factor in the development of several chronic conditions. Physical exercise has been postulated as an auspicious strategy to counteract age-related disorders preventing premature mortality. However, the effects of chronic exercise training on 1,25-dihydr...

Background A growing body of scientific works investigating the physio-pathological mechanisms behind cardiovascular disease has suggested that vitamin D deficiency could play a key role on its development. However, it remains unclear whether its active form (1,25-dihydroxyvitamin D [1,25(OH)2D] is associated with cardiometabolic risk factors in he...

To determine the acute effect of a single high-intensity interval training (HIIT) session on testosterone and cortisol levels in healthy individuals, a systematic search of studies was conducted in MEDLINE and Web of Science databases from inception to February 2020. Meta-analyses were performed to establish the acute effect of HIIT on testosterone...

Purpose Physical inactivity and ageing are associated with imbalances in anabolic/catabolic steroid hormones, jeopardizing health. We investigated the effects of three types of training on plasma steroid hormone levels in physically inactive, middle-aged adults. Methods A 12-week randomized controlled trial was performed with a parallel-group desi...

The present work aimed to examine the association between physical activity (PA) and sedentary behaviour with maximal fat oxidation (MFO) in young individuals. A total of 77 active adults (30 women; 22.8 ± 4.5 years) were included in this cross-sectional study in which PA and sedentary behaviour were measured using accelerometers for 7 consecutive...

It is currently unknown the most effective potentiation protocol to increase maximum strength. Hence, we investigated the separated and combined effects of post-tetanic potentiation (PTP) induced by whole- body electrostimulation (WB-EMS) and post-activation potentiation (PAP) induced by voluntary maximum isometric contractions on maximum isometric...

The constrained total energy expenditure (TEE) model posits that progressive increases in physical activity (PA) lead to increases in TEE; but after certain PA threshold, TEE plateaus. Then, a compensatory reduction in the expenditure of non-essential activities constrains the TEE. We hypothesized that high PA levels as locomotion associate with a...

Objectives To investigate the feasibility and acceptability of three different 8h time-restricted eating (TRE) schedules (i.e., early TRE, late TRE, and self-selected TRE) over 4 weeks in adults with overweight/obesity from southern Spain. Methods A total of 22 adults with overweight/obesity and a baseline eating window ≥12h (13 women; 48 ± 10 yea...

Purpose: The ergogenic effect of caffeine on exercise of maximum intensity has been well established. However, there is controversy regarding the effect of caffeine on shifting substrate oxidation at submaximal exercise. The aim of this study was to investigate the effect of acute caffeine ingestion on whole-body substrate oxidation during 1 h of...

Purpose: Potential interactions between sedentary behaviour, physical activity (PA), and physical fitness with 25-hydroxyvitamin D (25(OH)D) status have been previously suggested. However, data are scarce concerning the association between these predictors of general health and the main active metabolite of vitamin D, the 1,25-dihidroxyvitamin D (...

The aims of this study were to (I) determine the differences and relationship between the overhead press and split jerk performance in athletes involved in weightlifting training, and (II) explore the magnitude of these differences in one-repetition maximum (1RM) performances between sexes. Sixty-one men (age: 30.4 ± 6.7 years; height: 1.8 ± 0.5 m;...

Fat oxidation decreases with age, yet no studies have previously investigated if aging affects the maximal fat oxidation rate (MFO) during exercise in men and women differently. We hypothesized that increased age would be associated with a decline in MFO and this would be more pronounced in women due to menopause, compared with men. In this cross-s...

The present work examines the relationships between maximal fat oxidation during a graded exercise test (MFO), the intensity of exercise that elicits MFO (Fatmax), and traditional cardiometabolic risk factors in healthy, sedentary adults. A total of 119 (81 women) young, sedentary adults (22.1±2.2 years old), and 71 (37 women) middle-aged, sedentar...

By using deceptive experiments in which participants are informed that they received caffeine when, in fact, they received an inert substance (i.e., placebo), several investigations have demonstrated that exercise performance can be enhanced to a similar degree as a known caffeine dose. This ‘placebo effect’ phenomenon may be part of the mechanisms...

The present study aimed to investigate the effects of a 12-week concurrent training intervention on cardiometabolic health in obese men. Twelve obese men (42.5 ± 5.3 years old) participated in the current 12−week randomized controlled trial with a parallel group design. The participants were randomly assigned to a concurrent training group or to a...

This study aimed to examine the association of heart rate (HR) and heart rate variability (HRV) with cardiorespiratory fitness (CRF) in adults. This cross-sectional study included 204 participants: 132 young adults (67% women; 22.3 ± 2.3 years) and 72 middle-aged adults (53% women; 53.2 ± 5 years). HR and HRV were measured using a Polar RS800CX hea...

The main active metabolite of vitamin D, the 1,25-dihydroxyvitamin D (1,25(OH)2D), and the shed form of the α-Klotho gene (S-Klotho) play an important role in ageing-related physiological processes and are currently considered powerful anti-ageing renal biomarkers. We aimed to investigate the relationship between 1,25(OH)2D and S-Klotho plasma leve...

Objective To study the associations of dietary factors with S-Klotho plasma levels in young adults. We also aimed to study whether body composition and cardiometabolic risk factors affected the association between dietary factors and S-Klotho plasma levels. Methods A total of 139 young adults took part in this study. Dietary factors were measured...

The association of physical activity and fitness with sleep still remains unclear since there is a lack of studies in this field of research using objective measurements of these variables. This study aimed to investigate the association of objectively-measured sedentariness, physical activity levels, and physical fitness with sleep quantity and qu...

The associations between cardiovascular disease (CVD) risk factors and heart rate variability (HRV) have shown some inconsistencies. To examine the impact of the different Kubios threshold-based artefact correction levels on the associations between different CVD risk factors and a heart rate variability (HRV) score in three independent human cohor...

Background: High-intensity interval training (HIIT) is an effective approach to improve physical fitness, but consuming beer, which is a regular practice in many physically active individuals, may interfere with these effects. The purposes of this study were to investigate the effects of a 10-week (2 days/week) HIIT program on cardiorespiratory fi...

Background and aims To study the relationships between different dietary factors (i.e., energy, macronutrient and fatty acid intake, food group consumption, and dietary pattern) and basal fat oxidation (BFox) and maximal fat oxidation during exercise (MFO) in sedentary adults. Method and Resulss A total of 212 (n=130 women; 32.4±15.1 years) sedent...

Background Heart rate variability (HRV) is a psycho-physiological phenomenon with broad health implications. Different data analysis methods have been used to assess the autonomic nervous system activity, but the validation of new indexes that accurately describe its balance through non-invasive methods (i.e., HRV analysis) is of clinical interest....

Objective: This study aimed to describe the energy expenditure (EE) and macronutrient oxidation response to an individualized nonshivering cold exposure in young healthy adults. Methods: Two different groups of 44 (study 1: 22.1 [SD 2.1] years old, 25.6 [SD 5.2] kg/m2 , 34% men) and 13 young healthy adults (study 2: 25.6 [SD 3.0] years old, 23.6...

Objective To study the association between usual dietary factors (dietary energy density, nutrient intake, food group consumption, and dietary pattern) and brown adipose tissue (BAT) volume/18F-fluorodeoxyglucose (18F-FDG) uptake after personalized cold exposure in young healthy adults. Methods A total of 122 young adults (n=82 women; 22.0±2.1 yea...

The present work examines the relationships of objectively measured sedentary time and physical activity (PA) with maximal fat oxidation during exercise (MFO) and the intensity of exercise that elicits MFO (Fatmax), in young and middle-aged men and women. A total of 121 young sedentary adults (81 women, age 22.1±2.12 years, body mass index 25.2±4.9...

Sleep and Klotho have both been closely related to the ageing process, both playing a substantial role in the endocrine and immune systems and, thereby, in oxidative stress and chronic inflammation. However, there are no studies elucidating the relationship between sleep and Klotho. Therefore, this study investigated the association of sleep quanti...

Heart rate variability (HRV) is a valid and non-invasive indicator of cardiac autonomic nervous system functioning. Short-term HRV recordings (e.g., 10 min long) produce data that usually is manually processed. Researcher subjective decision-making on data processing could produce inter- or intra-researcher differences whose magnitude has not been...

It is unknown whether resting fat oxidation (RFO), maximal fat oxidation (MFO) and FatMax (intensity at which MFO is reached) are related to cardiometabolic risk (CMR). Thus, the aim of this study was to examine the association of RFO, MFO and FatMax with CMR. 81 healthy adults (n=31 women; 22.72 ± 4.40 years) participated in this cross-sectional s...

Obesity and sleep disturbances are both related to endocrine and metabolic alterations, cardiovascular disease, and impaired daytime functioning and mood. However, the bidirectional relationship between these conditions and the underlying mechanisms still remain unclear. This study aimed to investigate the potential association of anthropometric an...

This cross-sectional study aimed to examine the association of basal metabolic rate (BMR) and basal fat oxidation (BFox) with cardiometabolic risk and insulin sensitivity in sedentary middle-aged adults. A total of 71 healthy sedentary adults (37 women) aged 40-65 years participated in the current study. Data were collected during the baseline asse...

Background Obesity and short sleep duration have both been related to endocrine and metabolic alterations, type II diabetes mellitus, life-threating cardiovascular diseases, and impaired daytime functioning and mood. However, the bidirectional relationship between these conditions and underlying mechanisms still remain unclear, especially in young...

The authors have requested that this preprint be withdrawn due to author disagreement.

The aim of the present study was to investigate the relationship of sleep quality and time with basal metabolic rate (BMR) and fuel oxidation in basal conditions and during exercise in sedentary middle-aged adults. We also studied the mediation role of dietary intake and adherence to the traditional Mediterranean Diet in the relationship between sl...

Background Unhealthy lifestyle and aging negatively impact sexuality; consequently, the prevalence of sexual problems increases sharply in middle-aged adults, but the determinants of low sexual desire and sexual dysfunction are not fully elucidated. Aims To investigate the association of cardiometabolic profile, free testosterone plasma levels, bo...

Female sex hormones fluctuate in a predictable manner throughout the menstrual cycle in eumenorrheic women. In studies conducted in both animal and humans, estrogen and progesterone have been found to exert individual metabolic effect during both rest and exercise, suggesting that estrogen may cause an increase in fat oxidation during exercise. How...

The method used to select representative gas exchange data from large datasets influences the resting metabolic rate (RMR) returned. This study determines which of three methods yields the lowest RMR (as recommended for use in human energy balance studies), and in which method the greatest variance in RMR is explained by classical determinants of t...

Background & aims: This study compares the influence of different exercise training programs on basal metabolic rate (BMR) and fat oxidation, in basal conditions (BFox) and during exercise (MFO), in sedentary, middle-aged adults. Methods: The study subjects of this 12 week-long, randomised controlled trial, were 71 middle-aged adults (age 53.5 ±...

Objective: This study investigates the effects of different training modalities on sleep quality parameters. Methods: A total of 69 (52.7% women) middle-aged sedentary adults were randomized to: (i) control group, (ii) physical activity recommendation from the World Health Organization, (iii) high intensity interval training (HIIT), and (iv) hig...

Heart rate variability (HRV) is a non-invasive indicator of autonomic nervous system function. HRV recordings show artefacts due to technical and/or biological issues. The Kubios software is one of the most used software to process HRV recordings, offering different levels of threshold-based artefact correction (i.e., Kubios filters). The aim of th...

Background: Soluble Klotho (S-Klotho) is an aging suppressor with a close link with inflammation. However, it is still unknown whether the dietary inflammatory potential is associated with S-Klotho plasma level. We aimed to investigate the association of the Dietary Inflammatory Index (DII) with S-Klotho plasma levels in middle-aged sedentary adul...