Exercise to Lower Postprandial Lipemia: Why, When, What and How.

We review recent findings on the ability of exercise to lower postprandial lipemia (PPL). Specifically, we answer why exercise is important in lowering PPL, when it is most effective to exercise to achieve this, what the preferred exercise is and how exercise reduces PPL. Most findings confirm the power of exercise to lower PPL, which is an independent risk factor for cardiovascular disease. Exercise is most effective when performed on the day preceding a high- or moderate-fat meal. This effect lasts up to approximately two days; therefore, one should exercise frequently to maintain this benefit. However, the time of exercise relative to a meal is not that important in real-life conditions, since one consumes several meals during the day; thus, an exercise bout will inevitably exert its lowering effect on PPL in one or more of the subsequent meals. Although moderate-intensity continuous exercise, high-intensity intermittent exercise, resistance exercise and accumulation of short bouts of exercise throughout the day are all effective in lowering PPL, submaximal, high-volume interval exercise seems to be superior, provided it is tolerable. Finally, exercise reduces PPL by both lowering the rate of appearance and increasing the clearance of triacylglycerol-rich lipoproteins from the circulation.

Vitamin D status, vitamin D intake, and sunlight exposure in adults adhering or not to periodic religious fasting for decades.

We investigated whether periodic abstinence from foods of animal origin and a conservative lifestyle, with reduced sunlight exposure, affect vitamin D status. In a cross-sectional design, we measured the serum 25-hydroxyvitamin D concentration and assessed dietary vitamin D intake and sunlight exposure in 200 adults adhering to religious fasting for decades and in 200 non-fasters, with no differences between groups in bone mineral density. Fasters showed lower 25-hydroxyvitamin D concentration than non-fasters in winter and spring. Vitamin D intake and some indices of sunlight exposure (including two related to winter and spring) were lower in fasters, and 378 of the 400 participants exhibited vitamin D insufficiency or deficiency. In conclusion, individuals following a religious lifestyle had lower vitamin D intake, sunlight exposure and, at times, serum 25-hydroxyvitamin D concentration than controls, although these differences did not impact bone health.

A Comparison of Leg Muscle Oxygenation, Cardiorespiratory Responses, and Blood Lactate between Walking and Running at the Same Speed.

It is not known whether different gait modes, or movement patterns, at the same speed elicit differences in muscle oxygen oxygenation, expressed as muscle oxygen saturation (SmO2). Thus, the aim of this study was to compare the oxygenation of two leg muscles (vastus lateralis and gastrocnemius medialis), as well as the heart rate, respiratory gases, and blood lactate between two gait modes (walking and running) of the same speed and duration. Ten men walked and ran for 30 min each at 7 km/h in a random, counterbalanced order. SmO2, heart rate, and respiratory gases were monitored continuously. Blood lactate was measured at rest, at the end of each exercise, and after 15 min of recovery. Data were analyzed by two-way (gait mode × time) or three-way (gait mode × muscle × time) ANOVA, as applicable. Heart rate and oxygen consumption were higher when running compared to walking. SmO2 was lower during exercise compared to rest and recovery, in gastrocnemius medialis compared to vastus lateralis, and in running compared to walking. Blood lactate increased during exercise but did not differ between gait modes. In conclusion, running caused higher deoxygenation in leg muscles (accompanied by higher whole-body oxygen uptake and heart rate) than walking at the same speed (one that was comfortable for both gait modes), thus pointing to a higher internal load despite equal external load. Thus, preferring running over walking at the same speed causes higher local muscle deoxygenation, which may be beneficial in inducing favorable training adaptations.

Dietary Intake of Soccer Players before, during and after an Official Game: Influence of Competition Level and Playing Position.

Physical demands in soccer differ according to league level and playing position and may influence nutritional requirements. This study examined the effect of competition level and playing position on dietary intake in male soccer players (SP). Diet was weighed and recorded by 123 SP for 3 days; before, on the day, and the day after an official match. SP in the Super League (SL, n = 33) division reported higher (p < 0.05) average three-day energy (195 ± 36 kJ/kg), carbohydrate (6.0 ± 1.1 g/kg), and protein (2.2 ± 0.5 g/kg) intakes compared to the intakes reported by SP in the 2nd (n = 30) (energy: 159 ± 31 kJ/kg; carbohydrate: 4.6 ± 1.2 g/kg; protein: 1.9 ± 0.4 g/kg), 3rd (n = 30) (energy: 153 ± 34 kJ/kg; carbohydrate: 4.5 ± 1.2 g/kg; protein: 1.7 ± 0.4 g/kg), and 4th (n = 30) (energy: 152 ± 36 kJ/kg; carbohydrate: 4.2 ± 1.2 g/kg; protein: 1.7 ± 0.5 g/kg) national leagues (mean ± SD). Furthermore, when data were analyzed by playing position (pooled data), wide midfielders reported higher (p < 0.05) energy (183 ± 33 kJ/kg), carbohydrate (5.4 ± 1.2 g/kg), and fat (1.5 ± 0.4 g/kg) intakes compared to central defenders (energy: 147 ± 37 kJ/kg; carbohydrate: 4.1 ± 1.1 g/kg; fat: 1.2 ± 0.4 g/kg). The dietary intake of SP may differ according to the playing position and competition level, possibly due to different metabolic demands in training and competition.

1H NMR study on the short- and long-term impact of two training programs of sprint running on the metabolic fingerprint of human serum.

Metabonomics is an established strategy in the exploration of the effects of various stimuli on the metabolic fingerprint of biofluids. Here, we present an application of (1)H NMR-based metabonomics on the field of exercise biochemistry. Fourteen men were assigned to either of two training programs, which lasted 8 weeks and involved sets of 80-m maximal runs separated by either 10 s or 1 min of rest. Analysis of pre- and postexercise serum samples, both at the beginning and end of training, by (1)H NMR spectroscopy and subsequent multivariate statistical techniques revealed alterations in the levels of 18 metabolites. Validated O-PLS models could classify the samples in regard to exercise, the separation being mainly due to lactate, pyruvate, alanine, leucine, valine, isoleucine, arginine/lysine, glycoprotein acetyls, and an unidentified metabolite resonating at 8.17 ppm. Samples were also classified safely with respect to training, the separation being mainly due to lactate, pyruvate, methylguanidine, citrate, glucose, valine, taurine, trimethylamine N-oxide, choline-containing compounds, histidines, acetoacetate/acetone, glycoprotein acetyls, and lipids. Samples could not be classified according to the duration of the rest interval between sprints. Our findings underline the power of metabonomics to offer new insights into the short- and long-term impact of exercise on metabolism.

Blood Lactate and Maximal Lactate Accumulation Rate at Three Sprint Swimming Distances in Highly Trained and Elite Swimmers.

We examined the blood lactate response, in terms of the maximal post-exercise concentration (Lamax), time to reach Lamax, and maximal lactate accumulation rate (VLamax), to swimming sprints of 25, 35, and 50 m. A total of 14 highly trained and elite swimmers (8 male and 6 female), aged 14-32, completed the 3 sprints in their specialization stroke with 30 min of passive rest in between. The blood lactate was measured right before and continually (every minute) after each sprint to detect the Lamax. The VLamax, a potential index of anaerobic lactic power, was calculated. The blood lactate concentration, swimming speed, and VLamax differed between the sprints (p < 0.001). The Lamax was highest after 50 m (13.8 ± 2.6 mmol·L-1, mean ± SD throughout), while the swimming speed and VLamax were highest at 25 m (2.16 ± 0.25 m·s-1 and 0.75 ± 0.18 mmol·L-1·s-1). The lactate peaked approximately 2 min after all the sprints. The VLamax in each sprint correlated positively with the speed and with each other. In conclusion, the correlation of the swimming speed with the VLamax suggests that the VLamax is an index of anaerobic lactic power and that it is possible to improve performance by augmenting the VLamax through appropriate training. To accurately measure the Lamax and, hence, the VLamax, we recommend starting blood sampling one minute after exercise.

Effects of Enriched-in-Oleuropein Olive Leaf Extract Dietary Supplementation on Egg Quality and Antioxidant Parameters in Laying Hens.

The objective of the present study was to evaluate the effects of an olive leaf extract obtained with an up-to-date laboratory method, when supplemented at different levels in laying hens' diets, on egg quality, egg yolk antioxidant parameters, fatty acid content, and liver pathology characteristics. Thus, 96 laying hens of the ISA-Brown breed were allocated to 48 experimental cages with two hens in each cage, resulting in 12 replicates per treatment. Treatments were: T1 (Control: basal diet); T2 (1% olive leaf extract); T3 (2.5% olive leaf extract); T4 (Positive control: 0.1% encapsulated oregano oil). Eggshell weight and thickness were improved in all treatments compared to the control, with T2 being significantly higher till the end of the experiment (p < 0.001). Egg yolk MDA content was lower for the T2 and T4 groups, while total phenol content and Haugh units were greater in the T2. The most improved fatty acid profile was the one of T3 yolks. The α-tocopherol yolk content was higher in all groups compared to T1. No effect was observed on cholesterol content at any treatment. Based on the findings, it can be inferred that the inclusion of olive leaf extract at a concentration of 1% in the diet leads to enhancements in specific egg quality attributes, accompanied by an augmentation of the antioxidant capacity.

Phenotypical Variation of Ruminal Volatile Fatty Acids and pH during the Peri-Weaning Period in Holstein Calves and Factors Affecting Them.

Two hundred and forty-three clinically healthy Holstein calves from eight commercial dairy farms were used to: (a) describe the evolutionary course of ruminal VFA concentration and pH during the peri-weaning period and (b) assess management factors affecting their phenotypical variation of these parameters. Management practices were recorded individually for each calf as these were not fixed within farms. Samples of ruminal fluid were collected at -7 d, 0 d, and 7 d relative to weaning. Gas chromatography was used to measure ruminal VFAs, and pH was measured on site. Linear mixed models for repeated measurements were used to assess the effects of management factors and their interactions. A large among-calves phenotypical variability was observed. Estimated marginal means showed that concentrations of acetate, butyrate, and total VFAs (but not of propionate) significantly decreased, while acetate propionate increased, from -7 d to 7 d. Age at weaning and body weight at -7 d were positively associated with total and several individual VFA concentrations. Group housing and late forage feeding pre-weaning were associated with higher VFA concentrations; the same factors, as well as step-weaning, were associated with pH values around 6. Feeding 7-8 L of milk replacer daily did not preclude a smooth transition, irrespective of weaning method.

Muscle metabolism and performance improvement after two training programmes of sprint running differing in rest interval duration.

Repeated-sprint training often involves short sprints separated by inadequate recovery intervals. The effects of interval duration on metabolic and performance parameters are unclear. We compared the effects of two training programmes, differing in rest interval duration, on muscle (vastus lateralis) metabolism and sprint performance. Sixteen men trained three times a week for 8 weeks, each training session comprising 2-3 sets of two 80-m sprints. Sprints were separated by 10 s (n = 8) or 1 min (n = 8). Both training programmes improved performance in the 100-, 200-, and 300-m sprints, but the improvement was greater in the 10-s group during the final 100 m of the 200- and 300-m runs. Independent of interval duration, training mitigated the drop of muscle ATP after two 80-m sprints. The drop in phosphocreatine and the increases in glucose-6-phosphate and fructose-6-phosphate after two 80-m sprints were greater in the 10-s group. In conclusion, training with a limited number of repeated short sprints (≤10 s) may be more effective in improving speed maintenance in 200- and 300-m runs when performed with a 1:1 rather than a 1:6 exercise-to-rest ratio. This may be due to a greater activation of glycolysis caused, in part, by the limited resynthesis of phosphocreatine during the very short rest interval.

Effects of Periodic Religious Fasting for Decades on Nutrient Intakes and the Blood Biochemical Profile.

The aim of the present study was to examine differences and correlations in nutrient intakes and serum parameters related to nutrient intake (lipid profile, vitamins, and trace elements) in 200 lifelong Christian Orthodox Church (COC) fasters with periodic abstinence from certain foods (predominantly of animal origin) for approximately half of the year and 200 non-fasting controls, all of whom did not take dietary supplements. Nutrient intakes were assessed through three-day dietary recalls. Blood samples were drawn for the analysis of potential biomarkers of nutrient intake. Fasters had lower energy intake, due to lower fat and protein intake, compared to non-fasters (p < 0.05). Fasters also had lower intakes of vitamins A, B1, B2, B6, B12, D, folate, pantothenate, sodium, calcium, zinc, and phosphorus. Most participants (in both groups) did not meet the recommended dietary allowances of most vitamins and elements. Most serum biochemical parameters did not reflect the differences in nutrient intakes between groups, and none exhibited a correlation coefficient above 0.5 with nutrient intakes. Our findings suggest that COC fasting is associated with reduced intake of many nutrients, although this does not seem to have an impact on the blood biochemical profile.

Therapeutic Benefits of Short-Arm Human Centrifugation in Multiple Sclerosis-A New Approach.

Short-arm human centrifugation (SAHC) is proposed as a robust countermeasure to treat deconditioning and prevent progressive disability in a case of secondary progressive multiple sclerosis. Based on long-term physiological knowledge derived from space medicine and missions, artificial gravity training seems to be a promising physical rehabilitation approach toward the prevention of musculoskeletal decrement due to confinement and inactivity. So, the present study proposes a novel infrastructure based on SAHC to investigate the hypothesis that artificial gravity ameliorates the degree of disability. The patient was submitted to a 4-week training programme including three weekly sessions of 30 min of intermittent centrifugation at 1.5-2 g. During sessions, cardiovascular, muscle oxygen saturation (SmO2) and electroencephalographic (EEG) responses were monitored, whereas neurological and physical performance tests were carried out before and after the intervention. Cardiovascular parameters improved in a way reminiscent of adaptations to aerobic exercise. SmO2 decreased during sessions concomitant with increased g load, and, as training progressed, SmO2 of the suffering limb dropped, both effects suggesting increased oxygen use, similar to that seen during hard exercise. EEG showed increased slow and decreased fast brain waves, with brain reorganization/plasticity evidenced through functional connectivity alterations. Multiple-sclerosis-related disability and balance capacity also improved. Overall, this study provides novel evidence supporting SAHC as a promising therapeutic strategy in multiple sclerosis, based on mechanical loading, thereby setting the basis for future randomized controlled trials.

(1)H NMR-based metabonomic investigation of the effect of two different exercise sessions on the metabolic fingerprint of human urine.

Physical exercise modifies animal metabolism profoundly. Until recently, biochemical investigations related to exercise focused on a small number of biomolecules. In the present study, we used a holistic analytical approach to investigate changes in the human urine metabolome elicited by two exercise sessions differing in the duration of the rest interval between repeated efforts. Twelve men performed three sets of two 80 m maximal runs separated by either 10 s or 1 min of rest. Analysis of pre- and postexercise urine samples by (1)H NMR spectroscopy and subsequent multivariate statistical analysis revealed alterations in the levels of 22 metabolites. Urine samples were safely classified according to exercise protocol even when applying unsupervised methods of statistical analysis. Separation of pre- from postexercise samples was mainly due to lactate, pyruvate, hypoxanthine, compounds of the Krebs cycle, amino acids, and products of branched-chain amino acid (BCAA) catabolism. Separation of the two rest intervals was mainly due to lactate, pyruvate, alanine, compounds of the Krebs cycle, and 2-oxoacids of BCAA, all of which increased more with the shorter interval. Metabonomics provides a powerful methodology to gain insight in metabolic changes induced by specific training protocols and may thus advance our knowledge of exercise biochemistry.

Acute resistance exercise results in catecholaminergic rather than hypothalamic-pituitary-adrenal axis stimulation during exercise in young men.

Exercise is a paradigm of a stress situation. The adaptive response to stressors comprises the activation of the hypothalamic-pituitary-adrenal (HPA) axis and components of the autonomic sympathetic system. An aseptic inflammatory reaction is triggered by exercise, involving the stimulation of the so-called proinflammatory cytokines, such as tumor necrosis factor α (TNFα), interleukin-1 (IL-1), and IL-6. The anti-inflammatory cytokines IL-2, IL-8, and IL-10 increase moderately during resistance exercise. To investigate the effect of a short bout of resistance exercise on components of the stress and inflammatory responses during the exercise period, 17 healthy, young, untrained male volunteers were studied during 3 equal consecutive cycles of resistance exercises of 30 min total duration. Blood sampling was performed at baseline and at the end of each cycle. Lactate, cortisol, catecholamines (epinephrine, norepinephrine), IL-1α, IL-1ß, IL-2, IL-6, IL-8, IL-10, epidermal growth factor (EGF), and monocyte chemotactic protein-1 (MCP-1) were measured at all time-points. Circulating levels of catecholamines and lactate increased significantly (P < 0.05) whereas cortisol did not. During the time course of the exercise, circulating levels of TNFα, IL-2, and EGF increased, whereas MCP-1 decreased significantly. IL-1α, IL-1ß, IL-6, IL-8, and IL-10 levels did not change significantly. Statistically significant positive linear correlations were found between areas under the curve for increases in levels of IL-2 and TNFα, TNFα and cortisol, as well as epinephrine and norepinephrine. We conclude that acute resistance exercise results in catecholaminergic, but not HPA axis stimulation during exercise, in parallel with a mild inflammatory reaction. The absence of a major inflammatory reaction and of a cortisol increase during acute resistance exercise makes this a good candidate for the exercise of sedentary individuals.

Effect of chronic exercise on DNA fragmentation and on lipid profiles in rat skeletal muscle.

The concentration and fatty acid composition of phospholipids in animal cells are important determinants of membrane function. Membrane function may influence apoptosis, a biological process that is crucial for the normal development and function of the body. Few and conflicting data exist regarding the effect of chronic exercise on apoptosis in skeletal muscle, and no data exist regarding the effect of chronic exercise on the fatty acid composition of individual muscle phospholipids. We therefore examined the effects of 8 weeks of voluntary wheel running on DNA fragmentation (an index of apoptosis) and on the concentration and fatty acid composition of individual muscle phospholipids and ceramide (a lipid involved in apoptotic signalling) in rat gastrocnemius muscle by comparing 11 trained and 14 untrained male Wistar rats. The trained animals had significantly (P < 0.05) higher cytochrome c oxidase activity (an index of aerobic adaptation) and lower phosphatidyl inositol concentration compared with their untrained counterparts. Groups did not differ in DNA fragmentation or any other lipid parameter. Our findings suggest that chronic wheel running did not affect apoptosis or the concentration and fatty acid composition of most phospholipids and ceramide in rat gastrocnemius muscle. Given the participation of several phospholipids and ceramide in apoptotic signalling, it appears that the lack of changes in the lipid parameters is in agreement with the lack of change in DNA fragmentation with exercise.

Exercise in the management of obesity.

Obesity is a multifactorial disease with increasing incidence and burden on societies worldwide. Obesity can be managed through everyday behavioral changes involving energy intake and energy expenditure. Concerning the latter, there is strong evidence that regular exercise contributes to body weight and fat loss, maintenance of body weight and fat reduction, and metabolic fitness in obesity. Appropriate exercise programs should ideally combine large negative energy balance, long-term adherence, and beneficial effects on health and well-being. Endurance training appears to be the most effective in this respect, although resistance training and high-intensity interval training play distinct roles in the effectiveness of exercise interventions. With weight regain being so common, weight loss maintenance is probably the greatest challenge in the successful treatment of obesity. There is an established association between higher levels of physical activity and greater weight loss maintenance, based on the abundance of evidence from prospective observational studies and retrospective analyses. However, proving a causative relationship between exercise and weight loss maintenance is difficult at present. Exercise has the potential to alleviate the health consequences of obesity, even in the absence of weight loss. All in all, exercise constitutes an indispensable, yet often underestimated, tool in the management of obesity.

Long-term exercise increases the DNA binding activity of peroxisome proliferator-activated receptor gamma in rat adipose tissue.

The aim of the present study was to examine the effect of 8 weeks of voluntary wheel running on the gene expression, at the protein level, of 2 enzymes involved in lipogenesis (fatty acid synthase [FAS] and diacylglycerol acyl transferase 1), 2 proteins involved in lipolysis (hormone-sensitive lipase [HSL] and perilipin), and 3 transcription factors mediating the induction of genes involved in lipid metabolism (the alpha, gamma, and delta members of the peroxisome proliferator-activated receptor, or PPAR, family) in rat liver, gastrocnemius muscle, epididymal fat, and subcutaneous fat. Proteins were measured through Western blot analysis in the tissues of 11 trained and 14 untrained rats. The trained rats had lower FAS in the liver; higher FAS, HSL, and perilipin in epididymal fat; and higher HSL in subcutaneous fat. In addition, the trained rats had higher total protein concentrations in both fat depots. No significant differences in the liver, muscle, or adipose tissue PPAR contents were found between groups. However, the DNA binding activity of PPARgamma, measured through an enzyme immunoassay-based method, was higher in both fat depots of the trained rats. Our findings suggest that long-term wheel running had significant effects on the concentrations of proteins playing key roles in lipogenesis and lipolysis in rat liver and adipose tissue. These effects may be due to PPAR activation rather than induction, rendering the transcriptional regulation of target genes more economical and flexible. The activation of PPARgamma with exercise may mediate its beneficial effect on insulin sensitivity.

Resistance exercise does not affect the serum concentrations of cell adhesion molecules.

BACKGROUND: Cell adhesion molecules are proteins expressed on the surface of a variety of cells and mediate the leucocyte response to inflammation. Some of these molecules are released to the plasma as soluble forms, whose presence indicates the degree of vascular endothelial activation or dysfunction. Increased concentrations of soluble adhesion molecules are thought to hamper the immune response and mediate the atherosclerotic inflammatory process. Studies on the effect of exercise on the concentrations of soluble adhesion molecules have almost exclusively used aerobic exercise. AIM: To assess the effect of resistance exercise on the serum concentrations of five cell adhesion molecules during and immediately after 30 min of exercise in lean and obese participants. METHODS: Fourteen healthy young men (eight lean and six obese) performed 3 sets of 10 resistance exercises with 10-12 repetitions at 70-75% of one repetition maximum in a circuit training fashion. Venous blood samples were drawn at baseline and at the end of the first, second and third sets. The serum concentrations of vascular cell adhesion molecule-1, intercellular cell adhesion molecule-1, E-selectin, P-selectin and L-selectin were measured in a biochip array analyser. RESULTS: No significant changes were observed in the concentrations of these cell adhesion molecules during exercise, or between lean and obese participants. CONCLUSION: Our data indicate that resistance exercise of moderate to high intensity does not affect the serum concentrations of cell adhesion molecules in healthy young lean or obese men, suggesting no considerable negative effect on immune function.

IGF-1 Gene Expression in Rat Colonic Mucosa After Different Exercise Volumes.

The evidence is increasing for a close link between the insulin/insulin-like growth factor (IGF) system and colon cancer prevention by physical exercise. To reveal exercise-induced alterations in colon mucosa, gene expression of IGF-1 and related genes and serum IGF-1 were investigated. Twenty male Wistar rats performed a 12 week voluntary exercise program. Nine rats served as the control group. Gene expression of IGF-1, IGF-1 receptor (IGF-1R) and IGF-binding protein 3 (IGF-BP3) were quantified by real-time RT-PCR. Circulating IGF-1 was analyzed exercise volume-dependent. Based on 3 distinguished groups with low (L-EX, <2629 m·night(-1)), medium (M-EX, 3003-7458 m·night(-1)) and high exercise volume (H-EX, >8314 m·night(-1)), we observed lower serum IGF-1 levels (P < 0.05) in all exercise groups as compared to the control group and IGF-1 levels declined proportional to the increase in exercise volume. A significant (p < 0.05) positive correlation was found between IGF-1 concentration and body mass (r = 0.50) and a significant negative correlation exists between body mass and exercise volume (r = -0.50). Significant differences in colonic mRNA levels of IGF-1, IGF-1R and IGF-BP3 could not be observed. Based on our data we propose that the exercise as well as the body mass reduction leads to a decrease in circulating IGF-1 and this might represent a prime link to colon cancer prevention. Key pointsThere were significantly lower serum IGF-1 levels in all exercise groups as compared to the control group.GF-1 levels declined proportional to the increase in exercise volume.A significant positive correlation was found between IGF-1 concentration and body mass and a significant negative correlation was found between body mass and exercise volume.Significant differences in colonic mRNA levels of IGF-1, IGF-1R and IGF-BP3 could not be observed.

Increased Triacylglycerol Lipase Activity in Adipose Tissue of Lean and Obese Men During Endurance Exercise.

Context: Although there is increasing information on the mechanism of lipolysis in adipose tissue, the effect of exercise on individual factors of lipolysis is less well understood. Objective: We compared changes in adipose-tissue triacylglycerol lipase activity and gene expression of adipose triacylglycerol lipase (ATGL), hormone-sensitive lipase (HSL), monoacylglycerol lipase, perilipin 1, and comparative gene identification 58 (CGI-58) during exercise between lean and obese men. Design and Participants: Seven lean and nine obese men cycled for 30 minutes at a heart rate of 130 to 140 beats per minute. At baseline and 5, 10, 20, and 30 minutes of exercise, we sampled subcutaneous adipose tissue for triacylglycerol lipase activity and mRNA determination, and blood for glycerol, nonesterified fatty acid, glucose, lactate, insulin, and catecholamine determination. Setting: The study was conducted at a university research unit. Results: Triacylglycerol lipase activity increased at 10 minutes of exercise in the lean men and returned to baseline at 20 and 30 minutes. In the obese men, it was higher than baseline at 10, 20, and 30 minutes and higher than the corresponding values in the lean men at 20 and 30 minutes. No changes in mRNA levels were found during exercise, but the obese men had lower mRNA levels of ATGL, HSL, and CGI-58 compared with the lean men. Conclusion: Our findings suggest different patterns of lipolytic stimulation during endurance exercise between lean and obese men. Differences in lipolytic rates seem to be due to differences in protein amount or activity, not mRNA levels.

Duration of coffee- and exercise-induced changes in the fatty acid profile of human serum.

Prolonged moderate exercise increases the concentration of nonesterified fatty acids (NEFA) and the ratio of unsaturated to saturated (U/S) NEFA in human plasma. The present study examined the duration of these effects and compared them with the effects of coffee ingestion. On separate days and in random order, seven men and six women 1) cycled for 1 h, 2) ingested coffee containing 5 mg caffeine/kg body mass, 3) ingested coffee followed by exercise 1 h later, and 4) did nothing. Blood samples were drawn at 0, 1, 2, 4, 8, 12, and 24 h. Serum was analyzed for lactate, glucose, glycerol, individual NEFA, triacylglycerols, total cholesterol, and HDL cholesterol. Exercise elevated the U/S NEFA and the percentage of oleate, while decreasing the percentages of palmitate and stearate, at the end of exercise but not subsequently. Consumption of coffee triggered a lower lipolytic response with no alterations in U/S or percentages of individual NEFA. These findings may prove useful in discovering mechanisms mediating the effects of exercise training on the fatty acid profile of human tissues.