Dietary polyphenol intake in the Canadian population: Findings from the 2015 Canadian Community Health Survey-Nutrition

OBJECTIVES

This study aimed to estimate usual polyphenol intake among Canadians using the nationally representative 2015 Canadian Community Health Survey-Nutrition and to explore the main dietary contributors to polyphenol intake and the sociodemographic and lifestyle factors that may impact polyphenol intake.

METHODS

Dietary information was collected from 19,409 respondents using 24-h dietary recalls. The polyphenol content of foods was estimated using the Phenol-Explorer Database (version 3.6). Daily intake values for total polyphenols (adjusted to energy intake), main classes, and subclasses were calculated for each respondent and dietary recall. Usual intake was estimated by age/sex groups and by sociodemographic and lifestyle characteristics independently for adults and children using the National Cancer Institute method. Given-day arithmetic mean polyphenol intakes and mean proportions of main classes contributing to sum total polyphenol intakes were explored. Population proportions were used to determine dietary contributors.

RESULTS

Usual total polyphenol intake was 1119.3 mg/1000 kcal/day (95% CI: 1090.5, 1148.1) for adults ≥ 19 years and 473.0 mg/1000 kcal/day (95% CI: 454.9, 491.0) for children 2‒18 years. Generally, total polyphenol intakes differed by age, sex, ethnicity, and household education status and were higher among coffee and tea consumers. Most polyphenols came from flavonoids (40.0%) and phenolic acids (49.8%), with children consuming more flavonoids and other polyphenols and adults more phenolic acids. The top food contributors to polyphenol intake were coffee (26.8%), tea (8.9%), fruit juice (4.2%), banana (4.1%), and apple (3.8%).

CONCLUSION

Usual intake of total polyphenols among Canadians differed primarily by age. Non-alcoholic beverages were top contributors to total polyphenol intake.

An Exploration of Dietetic Students' Experiences in a Noncourse-based Service-Learning Opportunity in a Canadian Academic Setting

Purpose: To investigate the experiences of dietetic students in a faculty-supervised, noncourse-based service-learning (NSL) opportunity called Nutrition Ignition! (NI!) to understand how NSL activities contribute to dietetic education.Methods: This study used focus group methodology. A convenience sample was recruited from current members of NI!. Participants completed a brief demographic questionnaire and then engaged in a focus group discussion led by a trained moderator who followed a semi-structured guide. Six focus group discussions were transcribed, and a common theme template was developed by researchers.Results: Out of 46 eligible members of NI!, 33 agreed to participate. The main reasons participants joined NI! were to develop professional skills and to help children in the community. Participants discussed many outcomes from their participation in NI!, including enhanced communication skills, especially in terms of knowledge translation; increased ability to be flexible and adapt to "real-world" situations; deeper awareness of the research process; and expanded world view.Conclusion: This study suggests that NSL is an effective way to build dietetic students' personal and professional skills and provide an additional opportunity in academic settings to prepare dietetic students for entry-level practice.

Acceptability, Helpfulness, and Utility of the Healthy Lunch Box Booklet (HLBB) for Parents and School-Age Children

Purpose: School lunches are of poor nutritional quality in Canada. Parents play an important role in the preparation of school lunches for young children. This study aimed to evaluate the acceptability and helpfulness of the Healthy Lunch Box Booklet (HLBB) to support parents in packing healthy school lunches for their children.Methods: The HLBB was distributed at four schools in London, Ontario to students in full-day Kindergarten to Grade three. Parents were asked to complete an online survey from April to November 2019.Results: Parents (n = 58) reported the HLBB to be helpful (96.3%) and found the sections on new school lunch and snack ideas and nutritional information (e.g., label reading) particularly useful. Some parents also stated that the HLBB created opportunities to interact with their children regarding school lunch preparation. In terms of perceived impacts, parents reported increased confidence (68.6%) and learning something new (79.6%) about school lunch preparation and felt that their children's diet was impacted accordingly.Conclusions: The HLBB was found to be an acceptable and useful nutrition resource that supports parents in packing healthy school lunches for their children and therefore warrants further study.

Children's Perceptions of the Ontario Student Nutrition Program (OSNP) in Southwestern Ontario, Canada

Purpose: This study aimed to explore children's lived experiences with the Ontario Student Nutrition Program (OSNP), a free, school-based snack program implemented in elementary schools in Southwestern, Ontario, Canada, to gain insights into future school food programs (SFP).Methods: Focus group discussions (n=17) were conducted with 105 children in Grades 5 to 8 in seven elementary schools. Focus groups were audio-recorded, transcribed, and coded for themes using inductive content analysis.Results: Overall, children appreciated the OSNP and felt that it filled a need in students. Children also reported a willingness to try novel food items. For future SFPs, participants recommended that input be sought from children to ensure food preferences were considered. Children also discussed wanting more appealing food offerings that may include some choice. Finally, children also mentioned wanting a fair and equitable distribution of food in classrooms.Conclusions: Children appreciated the OSNP and reported benefits to themselves and their peers. They also provided some valuable recommendations for future SFPs. If a nationally funded SFP is to be considered in Canada, children expressed the need to make the program equitable, while still allowing schools the flexibility to meet their unique needs and preferences.

Process evaluation of the Centrally Procured School Food Program (CPSFP) in Ontario, Canada: school-level perspectives

This study explored the implementation of the Centrally Procured School Food Program (CPSFP)-a free, universal, volunteer-led snack program for elementary school children. To assess participants' perceptions and experiences with the CPSFP, interviews were conducted in school-level participants (n = 33) using a semi-structured interview guide. Fifteen on-site visits also were conducted at each school to observe implementation practices. Quantitative data were obtained through a general information form where participants provided school characteristics and weekly logbooks where they described program operations and food quality. Most participants expressed positive perceptions of the CPSFP, identifying it as a valuable program for their students. Successful program implementation was associated with an appreciation for the CPSFP and the participation of the school community. Challenges to program implementation included concerns with the volume and types of food provided, issues with classroom food delivery and distribution and communication challenges. Suggestions for improvement included building capacities and enhancing student engagement in the program. Participants provided an in-depth assessment of the implementation of the CPSFP. The lessons learned and suggestions provided may help not only enhance the reach, feasibility and fidelity of the CPSFP, but inform the best practices for similar programs.

Perspectives and Impact of a Parent-Child Intervention on Dietary Intake and Physical Activity Behaviours, Parental Motivation, and Parental Body Composition: A Randomized Controlled Trial

Adults and children in Canada are not meeting physical activity guidelines nor consuming sufficient nutrient-rich foods. High engagement in these unhealthy behaviours can lead to obesity and its associated diseases. Parent-child interventions aimed at obesity prevention/treatment have assisted families with making positive changes to their nutrition and physical activity behaviours. Given that the home environment shapes early health behaviours, it is important to target both parents and children when addressing diet and physical activity. One method that has been shown to improve health outcomes is co-active coaching. The current study explored the impact of a three-month co-active coaching and/or health education intervention on the dietary intake and physical activity behaviours of parents with overweight/obesity and their children (ages 2.5-10; of any weight). Body composition (i.e., body mass index [BMI] and waist circumference), changes in parental motivation with respect to physical activity and dietary behaviours, and parental perceptions of program improvements were collected. A concurrent mixed methods study comprised of a randomized controlled trial and a descriptive qualitative design was utilized. Fifty parent-child dyads were recruited and randomly assigned to the control (n = 25) or intervention (n = 25) group. Assessments were completed at baseline, mid-intervention (six weeks), post-intervention (three months), and six-month follow-up. A linear mixed effects model was utilized for quantitative analysis. Inductive content analysis was used to extract themes from parent interviews. No significant results were observed over time for the dependent measures. Parents in both control and intervention groups reported varied program experiences, including developing changes in perspective, increased awareness of habits, and heightened accountability for making positive changes in themselves, and consequently, their families. Parents also shared barriers they faced when implementing changes (e.g., time, weather, stress). Qualitatively, both groups reported benefitting from this program, with the intervention group describing salient benefits from engaging in coaching. This research expands on the utility of coaching as a method for behaviour change, when compared to education only, in parents with overweight/obesity and their children.

Assessment of Phenolic Compound Intake from Plant-Derived Products in Adolescents from Ontario, Canada

Purpose: To better understand which plant-derived products contribute to the usual daily total polyphenol content (TPC) intake of Canadian adolescents. Methods: A convenience sample from 2 southwestern Ontario high schools was obtained (n = 108). Students of all gender and ethnicity were invited to participate if they were enrolled in grades 9-12 and were between the ages of 13 and 18 years. To measure the usual intake of TPC found in fruits, vegetables, fruit juices, nuts and legumes, tea, and coffee and coffee-based beverages, participants completed a food frequency questionnaire. TPC of the tea, coffee and coffee-based beverages, and fruit juices were determined spectrophotometrically, and the TPC of all other food items were calculated using the Phenol-Explorer Database. Results: Participants' median consumption of TPC was 974 mg/day (25th, 75th percentile; 559, 2161, respectively). Fruit contributed 69% to TPC intake with 24% from vegetables; 3% from juice; 2% from tea, coffee, and coffee-based beverages; and 0% from nuts and pulses. No sex differences were found. Conclusion: The results of this exploratory study suggest that fruit is the major contributor to the daily TPC intake of adolescents in Ontario, Canada; however, a larger-scale study is warranted to confirm these findings.

Adolescent Attitudes and Beliefs Regarding Caffeine and the Consumption of Caffeinated Beverages

OBJECTIVES

To explore adolescents' attitudes and beliefs toward the consumption of caffeinated beverages and factors influencing their caffeinated beverage choice and consumption patterns.

DESIGN

Twenty focus groups were conducted with grades 9 to 12 secondary school students.

SETTING

Two secondary schools in London, Ontario, Canada.

PARTICIPANTS

This study included 166 adolescents, 42% of whom were male and 72% of whom were in grades 9 and 10.

PHENOMENON OF INTEREST

Adolescent views regarding caffeine and caffeinated beverages.

ANALYSIS

Three researchers independently conducted inductive content analysis on the data using the principles of the immersion-crystallization method.

RESULTS

Awareness levels regarding types of caffeinated beverages and their negative health effects were high in adolescents whereas awareness of other aspects of caffeine itself and recommended consumption levels were low. Adolescents also identified reasons for caffeine use, including providing energy, taste, accessibility, and image enhancement. Influences for caffeine use most noted by participants included parental role modeling, media and advertising, and social norms.

CONCLUSIONS AND IMPLICATIONS

Further education is needed to correct the misconceptions adolescents have regarding certain aspects of caffeine. By gaining a deeper understanding of adolescents' caffeine use, effective educational strategies may be developed to reduce its use and mitigate potential harms.

Sugar-Sweetened Beverages: Children's Perceptions, Factors of Influence, and Suggestions for Reducing Intake

OBJECTIVES

This study aimed to gain an in-depth understanding of children's perceptions of sugar-sweetened beverages (SSBs).

DESIGN

Nine focus groups were conducted in grade 5 and 6 elementary schoolchildren.

SETTING

Nine urban and rural elementary schools in London, Ontario, Canada.

PARTICIPANTS

Fifty-one children, 58% of which were male, 52% of whom were in grade 5, and 84% of whom were Caucasian.

PHENOMENON OF INTEREST

Children's views on sugar-sweetened beverages.

ANALYSIS

Three researchers conducted inductive content analysis on the data independently using the principles of the immersion-crystallization method.

RESULTS

Participants had a high level of awareness of beverages and their health effects, which was primarily targeted at the sugar content. Dominant factors that influenced children's beverage choices and consumption patterns included taste, parental control practices, accessibility, and advertising. Participants identified a wide array of strategies to reduce SSB consumption in children, including educational strategies for both children and parents and policy-level changes at both the government and school levels.

CONCLUSIONS AND IMPLICATIONS

Despite a high level of awareness of SSBs, children believed that further education and policies regarding SSBs were warranted. These data may prove helpful in designing effective interventions targeted at children and parents to reduce SSB consumption by children.

Does caffeine alter muscle carbohydrate and fat metabolism during exercise?

Caffeine, an adenosine receptor antagonist, has been studied for decades as a putative ergogenic aid. In the past 2 decades, the information has overwhelmingly demonstrated that it indeed is a powerful ergogenic aid, and frequently theories have been proposed that this is due to alterations in fat and carbohydrate metabolism. While caffeine certainly mobilizes fatty acids from adipose tissue, rarely have measures of the respiratory exchange ratio indicated an increase in fat oxidation. However, this is a difficult measure to perform accurately during exercise, and small changes could be physiologically important. The few studies examining human muscle metabolism directly have also supported the fact that there is no change in fat or carbohydrate metabolism, but these usually have had a small sample size. We combined the data from muscle biopsy analyses of several similar studies to generate a sample size of 16-44, depending on the measure. We examined muscle glycogen, citrate, acetyl-CoA, glucose-6-phosphate, and cyclic adenosine monophosphate (cAMP) in resting samples and in those obtained after 10-15 min of exercise at 70%-85% maximal oxygen consumption. Exercise decreased (p < 0.05) glycogen and increased (p < 0.05) citrate, acetyl-CoA, and glucose-6-phosphate. The only effects of caffeine were to increase (p < 0.05) citrate in resting muscle and cAMP in exercise. There is very little evidence to support the hypothesis that caffeine has ergogenic effects as a result of enhanced fat oxidation. Individuals may, however, respond differently to the effects of caffeine, and there is growing evidence that this could be explained by common genetic variations.

Caffeine's impairment of insulin-mediated glucose disposal cannot be solely attributed to adrenaline in humans

Caffeine (CAF) impedes insulin-mediated glucose disposal (IMGD) and increases plasma adrenaline concentrations ([ADR]; 0.6 nm). While the antagonism of ADR abolishes the CAF effect, infusion of ADR (0.75 nm) has no effect on IMGD. We have now examined CAF and ADR in concert to determine whether or not they elicit an additive response on IMGD. We hypothesized that CAF + ADR would elicit a greater effect than either CAF or ADR alone (i.e. that CAF effects would not be solely attributed to ADR). Subjects (n = 8) completed four trials in a randomized manner. An isoglycaemic-hyperinsulinaemic clamp was performed 30 min after the following treatments were administered: (1) placebo capsules and saline infusion ([ADR] = 0.29 nm) (PL trial), (2) CAF capsules (dose = 5 mg kg(-1)) and saline infusion ([ADR] = 0.62 nm) (CAF trial), (3) PL capsules and ADR infusion ([ADR] = 1.19 nm) (ADR trial), and (4) CAF capsules (dose = 5 mg kg(-1)) and ADR infusion ([ADR] = 0.93 nm) (CAF + ADR trial). As expected, CAF, ADR and CAF + ADR decreased (P <or= 0.05) IMGD compared to PL. CAF + ADR resulted in a more pronounced decrease in IMGD versus PL (42%) compared to CAF (26%) or ADR (24%) alone; however, the effect was not fully additive (P = 0.08). Furthermore, CAF decreased IMGD to a similar magnitude as ADR despite a 50% lower [ADR]. In summary, while ADR contributes to the CAF-induced impairment in IMGD, it is not solely responsible for caffeine's effects.

Acute caffeine ingestion does not impair glucose tolerance in persons with tetraplegia

Acute caffeine (Caf) ingestion impairs glucose tolerance in able-bodied humans during an oral glucose tolerance test (OGTT). The mechanism responsible for this effect remains unclear, however, it is suggested to be due to the accompanying increase in epinephrine concentration. We examined whether or not Caf would elicit a glucose intolerance in persons with tetraplegia (TP) who do not exhibit an increased epinephrine response following Caf ingestion. All TP [n = 14; 9 incomplete (Inc) lesion, 5 complete (Com) lesion] completed two OGTT 1 h after consuming either gelatin (Pl) or Caf capsules (dose = 4 mg/kg). Blood samples were collected at baseline (time = 0 min), 1 h after capsule ingestion (time = 60 min), and every 30 min during the OGTT (time = 90-180 min). Glucose, insulin, proinsulin, and C-peptide responses were similar (P > 0.05) between treatments, demonstrating no effect of Caf on glucose tolerance. This lack of a Caf effect may be due to the low epinephrine concentration that remained unchanged (P > 0.05) throughout all experiments. Interestingly, the Com exhibited a 50% higher glucose response (P <or= 0.05) and a 46% (P > 0.05) lower insulin response (vs. Inc), suggesting a more pronounced glucose intolerance within this subgroup. Furthermore, nine TP (5 Com, 4 Inc) had glucose levels of >or= 7.8 mM at the end of the OGTT (time = 180 min), classifying them as glucose intolerant. In summary, acute Caf ingestion does not increase epinephrine concentration or impair glucose tolerance in TP.

The glucose intolerance induced by caffeinated coffee ingestion is less pronounced than that due to alkaloid caffeine in men

Although acute alkaloid caffeine (CAF) ingestion results in an impaired glucose tolerance, chronic coffee (RCOF) ingestion decreases the risk of developing type 2 diabetes. This study examines the hypothesis that CAF ingestion impairs glucose tolerance to a greater extent than RCOF and that the ingestion of decaffeinated coffee (DECAF) results in a positive effect. Eleven healthy males underwent 4 double-blinded randomized trials. Each trial included the ingestion of either: 1) CAF in capsule form (4.45 mg/kg body weight), 2) RCOF (4.45 mg/kg body weight caffeine), 3) dextrose (placebo, PL) in capsule form, or 4) DECAF (equal in volume to the RCOF trial), followed 1-h later by a 2-h oral glucose tolerance test. Blood samples were collected at baseline (-30), 0 (time of treatment ingestion), 60 (initiation of oral glucose tolerance test), 75, 90, 120, 150, and 180 min. Area under the curve for glucose and insulin were higher (P < or = 0.05) following CAF than both PL and DECAF and, although a similar trend (P = 0.07) was observed following RCOF compared with DECAF, the effect was less pronounced. Interestingly, DECAF resulted in a 50% lower glucose response (P < or = 0.05) than PL, suggesting that the effects of PL and DECAF on glucose tolerance are not the same. These findings suggest that the effects of CAF and RCOF are not identical and may provide a partial explanation as to why acute CAF ingestion impairs glucose tolerance while chronic RCOF ingestion protects against type 2 diabetes.

The effect of caffeine on glucose kinetics in humans--influence of adrenaline

While caffeine impedes insulin-mediated glucose disposal in humans, its effect on endo-genous glucose production (EGP) remains unknown. In addition, the mechanism involved in these effects is unclear, but may be due to the accompanying increase in adrenaline concentration. We studied the effect of caffeine on EGP and glucose infusion rates (GIR), and whether or not adrenaline can account for all of caffeine's effects. Subjects completed three isoglycaemic-hyperinsulinaemic clamps (with 3-[(3)H]glucose infusion) 30 min after ingesting: (1) placebo capsules (n= 12); (2) caffeine capsules (5 mg kg(-1)) (n= 12); and either (3) placebo plus a high-dose adrenaline infusion (HAdr; adrenaline concentration, 1.2 nM; n= 8) or (4) placebo plus a low-dose adrenaline infusion (LAdr; adrenaline concentration, 0.75 nM; n= 6). With caffeine, adrenaline increased to 0.6 nM but no effect on EGP was observed. While caffeine and HAdr decreased GIR by 13 (P < 0.05) and 34% (P < 0.05) versus the placebo, respectively, LAdr did not result in a significant reduction (5%) in GIR versus the placebo. Due to the fact that both caffeine and LAdr resulted in similar adrenaline concentrations, but resulted in different decreases in GIR, it is concluded that adrenaline alone does not account for the effects of caffeine and additional mechanisms must be involved.

Glycogenin activity and mRNA expression in response to volitional exhaustion in human skeletal muscle

Glycogenolysis results in the selective catabolism of individual glycogen granules by glycogen phosphorylase. However, once the carbohydrate portion of the granule is metabolized, the fate of glycogenin, the protein primer of granule formation, is not known. To examine this, male subjects ( n = 6) exercised to volitional exhaustion (Exh) on a cycle ergometer at 75% maximal O2uptake. Muscle biopsies were obtained at rest, 30 min, and Exh (99 ± 10 min). At rest, total glycogen concentration was 497 ± 41 and declined to 378 ± 51 mmol glucosyl units/kg dry wt following 30 min of exercise ( P < 0.05). There were no significant changes in proglycogen, macroglycogen, glycogenin activity, or mRNA in this period ( P ≥ 0.05). Exh resulted in decreases in total glycogen, proglycogen, and macroglycogen as well as glycogenin activity ( P < 0.05). These decrements were associated with a 1.9 ± 0.4-fold increase in glycogenin mRNA over resting values ( P < 0.05). Glycogenolysis in the initial exercise period (0–30 min) was not adequate to induce changes in glycogenin; however, later in exercise when concentration and granule number decreased further, decrements in glycogenin activity and increases in glycogenin mRNA were demonstrated. Results show that glycogenin becomes inactivated with glycogen catabolism and that this event coincides with an increase in glycogenin gene expression as exercise and glycogenolysis progress.

Increases in glycogenin and glycogenin mRNA accompany glycogen resynthesis in human skeletal muscle

Glycogenin is the self-glycosylating protein primer that initiates glycogen granule formation. To examine the role of this protein during glycogen resynthesis, eight male subjects exercised to exhaustion on a cycle ergometer at 75% Vo2 max followed by five 30-s sprints at maximal capacity to further deplete glycogen stores. During recovery, carbohydrate (75 g/h) was supplied to promote rapid glycogen repletion, and muscle biopsies were obtained from the vastus lateralis at 0, 30, 120, and 300 min postexercise. At time 0, no free (deglycosylated) glycogenin was detected in muscle, indicating that all glycogenin was complexed to carbohydrate. Glycogenin activity, a measure of the glycosylating ability of the protein, increased at 30 min and remained elevated for the remainder of the study. Quantitative RT-PCR showed elevated glycogenin mRNA at 120 min followed by increases in protein levels at 300 min. Glycogenin specific activity (glycogenin activity/relative protein content) was also elevated at 120 min. Proglycogen increased at all time points, with the highest rate of resynthesis occurring between 0 and 30 min. In comparison, macroglycogen levels did not significantly increase until 300 min postexercise. Together, these results show that, during recovery from prolonged exhaustive exercise, glycogenin mRNA and protein content and activity increase in muscle. This may facilitate rapid glycogen resynthesis by providing the glycogenin backbone of proglycogen, the major component of glycogen synthesized in early recovery.

Caffeine ingestion before an oral glucose tolerance test impairs blood glucose management in men with type 2 diabetes

Caffeine ingestion negatively affects insulin sensitivity during an oral glucose tolerance test (OGTT) in lean and obese men, but this has not been studied in individuals with type 2 diabetes. We examined the effects of caffeine ingestion on insulin and glucose homeostasis in obese men with type 2 diabetes. Men (n = 12) with type 2 diabetes (age = 49 +/- 2 y, BMI = 32 +/- 1 kg/m(2)) underwent 2 trials, 1 wk apart, in a randomized, double-blind design. Each trial was conducted after withdrawal from caffeine, alcohol, exercise, and oral hypoglycemic agents for 48 h and an overnight fast. Subjects randomly ingested caffeine (5 mg/kg body weight) or placebo capsules and 1 h later began a 3 h 75 g OGTT. Caffeine increased (P < 0.05) serum insulin, proinsulin, and C-peptide concentrations during the OGTT relative to placebo. Insulin area under the curve was 25% greater (P < 0.05) after caffeine than after placebo ingestion. Despite this, blood glucose concentration was also increased (P < 0.01) in the caffeine trial. After caffeine ingestion, blood glucose remained elevated (P < 0.01) at 3 h postglucose load (8.9 +/- 0.7 mmol/L) compared with baseline (6.7 +/- 0.4 mmol/L). The insulin sensitivity index was lower (14%, P = 0.02) after caffeine than after placebo ingestion. Overall, despite elevated and prolonged proinsulin, C-peptide, and insulin responses after caffeine ingestion, blood glucose was also increased, suggesting an acute caffeine-induced impairment in blood glucose management in men with type 2 diabetes.

Caffeine ingestion does not impede the resynthesis of proglycogen and macroglycogen after prolonged exercise and carbohydrate supplementation in humans

The purpose of this study was to examine the effects of caffeine (Caf) ingestion on pro- (PG) and macroglycogen (MG) resynthesis in 10 healthy men. Subjects completed two trials, consisting of a glycogen-depleting exercise, while ingesting either Caf or placebo capsules. Throughout recovery, biopsies were taken at 0 (exhaustion), 30, 120, and 300 min, and 75 g of carbohydrate were ingested at 0, 60, 120, 180, and 240 min. Whereas Caf ingestion resulted in a higher blood glucose concentration and decreased glycogen synthase fractional velocity (P <or= 0.05), no effect was observed in either the amount or rate of PG and MG resynthesis. PG concentration increased significantly at each time point during recovery, whereas MG concentration remained unchanged until 120 min. The net rate of PG resynthesis was 115 mmol x kg dw(-1) x h(-1) during the first 30 min of recovery, and then it significantly decreased by 62% throughout the remaining 4.5 h of recovery. The net rate of MG resynthesis was 77% lower than the net rate of PG resynthesis during the first 30 min of recovery and remained constant throughout 5 h of recovery despite increasing levels of insulin. In conclusion, Caf ingestion does not impede the resynthesis of PG or MG after an extensive depletion of muscle glycogen and with the provision of exogenous dietary carbohydrate.