Performance enhancment by carbohydrate intake during sport: effects of carbohydrates during and after high-intensity exercise

Endogenous carbohydrate availability does not provide sufficient energy for prolonged moderate to high-intensity exercise. Carbohydrate ingestion during high-intensity exercise can therefore enhance performance.- For exercise lasting 1 to 2.5 hours, athletes are advised to ingest 30-60 g of carbohydrates per hour.- Well-trained endurance athletes competing for longer than 2.5 hours at high intensity can metabolise up to 90 g of carbohydrates per hour, provided that a mixture of glucose and fructose is ingested.- Athletes participating in intermittent or team sports are advised to follow the same strategies but the timing of carbohydrate intake depends on the type of sport.- If top performance is required again within 24 hours after strenuous exercise, the advice is to supplement endogenous carbohydrate supplies quickly within the first few hours post-exercise by ingesting large amounts of carbohydrate (1.2 g/kg/h) or a lower amount of carbohydrate (0.8 g/kg/h) with a small amount of protein (0.2-0.4 g/kg/h)

Exercise training as part of multidisciplinary rehabilitation in cancer survivors:an observational study on changes in physical performance and patient-reported outcomes

PURPOSE: To describe changes in physical performance and patient-reported outcomes in cancer survivors who participated in an exercise program as part of usual-care multidisciplinary rehabilitation and the influence of training adaptations during the coronavirus-19 (COVID-19) pandemic. METHODS: In an observational cohort study, cancer survivors underwent usual-care multidisciplinary rehabilitation including a 10-week exercise program. During the COVID-19 pandemic, the exercise program was adapted with reduced training time and frequency. Mean changes and 95% confidence intervals in physical performance (peak oxygen uptake (VO2peak), peak work rate during a steep ramp test (SRT-WRpeak), 6-min walking distance, muscle strength) and patient-reported outcomes (health-related quality of life, fatigue, anxiety, and depression) were assessed between the start and the end of the exercise program. Linear regression analysis, adjusting for baseline levels of outcomes, was used to investigate differences in changes in outcomes between participants who underwent the original and the adapted program. RESULTS: All outcomes statistically significantly improved over time, regardless of adaptations in the exercise program. VO2peak increased with 9.6% and 7.7% in the original and adapted program, respectively. Significant smaller improvements were observed in SRT-WRpeak (- 3.9%) and upper body muscle strength (- 10.8%) after participation in the adapted compared to the original program. No significant between-group differences were observed for other outcomes. CONCLUSION: Physical performance and patient-reported outcomes statistically and clinically significantly improved in cancer survivors who participated in an exercise program as part of usual-care multidisciplinary rehabilitation. Improvements of performance outcomes were smaller since the training adaptations, though only significant for SRT-WRpeak and upper body strength

Impact of caffeine and protein on postexercise muscle glycogen synthesis

BEELEN, M., J. VAN KRANENBURG, J. M. SENDEN, H. KUIPERS, and L. J. C. VAN LOON. Impact of Caffeine and Protein on Postexercise Muscle Glycogen Synthesis. Med. Sci. Sports Exerc., Vol. 44, No. 4, pp. 692–700, 2012. Background: Both protein and caffeine coingestion with CHO have been suggested to represent effective dietary strategies to further accelerate postexercise muscle glycogen synthesis in athletes. Purpose: This study aimed to assess the effect of protein or caffeine coingestion on postexercise muscle glycogen synthesis rates when optimal amounts of CHO are ingested. Methods: Fourteen male cyclists were studied on three different test days. Each test day started with a glycogen-depleting exercise session. This was followed by a 6-h recovery period, during which subjects received 1.2 gIkgj1 Ihj1 CHO, the same amount of CHO with 0.3 gIkgj1 Ihj1 of a protein plus leucine mixture (CHO + PRO), or 1.7 mgIkgj1 Ihj1 caffeine (CHO + CAF). All drinks were enriched with [U-13C6]-labeled glucose to assess potential differences in the appearance rate of ingested glucose from the gut. Muscle biopsies were collected immediately after cessation of exercise and after 6 h of postexercise recovery. Results: The plasma insulin response was higher in CHO + PRO compared with CHO and CHO + CAF (P G 0.01). Plasma glucose responses and glucose appearance rates did not differ between experiments. Muscle glycogen synthesis rates averaged 31 T 4, 34 T 4, and 31 T 4 mmolIkgj1 dry weightIhj1 in CHO, CHO + PRO, and CHO + CAF, respectively (P = NS). In accordance, histochemical analyses did not show any differences between net changes in Type I and Type II muscle fiber glycogen content between experiments. Conclusions: Coingestion of protein or caffeine does not further accelerate postexercise muscle glycogen synthesis when ample amounts of CHO (1.2 gIkgj1 Ihj1 ) are ingeste

Determinants of physical activity maintenance and the acceptability of a remote coaching intervention following supervised exercise oncology rehabilitation:a qualitative study

PurposeThe purpose of the study was to investigate perceived determinants of physical activity (PA) maintenance following supervised exercise oncology rehabilitation and the acceptability of a remote coaching intervention during this period.MethodsA phenomenological qualitative study with semi-structured interviews was conducted. Nineteen participants (16 women, 3 men) were recruited from the intervention (n = 12) and control group (n = 7) of a randomized controlled trial on the effectiveness of remote coaching following hospital-based, supervised exercise oncology rehabilitation. Participants in the intervention group received a 6-month remote coaching intervention after completing the exercise program, aimed at stimulating PA maintenance. The interviews were based on the Capability, Opportunity, and Motivation model of Behaviour (COM-B model) and the framework of acceptability (TFA) and were coded using template analysis.ResultsKey themes regarding determinants of PA maintenance were self-efficacy, PA habits, accountability, physical complaints, and facilities. Remote coaching was perceived acceptable because it stimulated PA maintenance by offering a source of structure and social support and thereby increased accountability. Moreover, it improved confidence to perform PA, leading to increased levels of self-efficacy. The remote nature of the intervention was perceived as convenient by some of the participants, while others would have preferred additional physical appointments.ConclusionsCancer survivors considered remote coaching acceptable to stimulate PA maintenance following supervised rehabilitation. Interventions should focus on increasing accountability, self-efficacy, forming habits, and helping cancer survivors to overcome barriers.Implications for Cancer SurvivorsThe ability to maintain PA beyond supervised exercise oncology programs depends on many determinants. Remote coaching interventions have potential to target individually relevant determinants following exercise programs in cancer survivors

Effects of remote coaching following supervised exercise oncology rehabilitation on physical activity levels, physical fitness, and patient-reported outcomes: a randomised controlled trial

Abstract Background Studies have shown that cancer survivors experience difficulties maintaining physical activity levels after participation in a supervised exercise rehabilitation program. This study aimed to assess the effectiveness of a six-month remote coaching intervention, following a supervised exercise oncology rehabilitation program on maintenance of PA levels; and improvement of aerobic capacity, muscle strength and patient-reported outcomes in cancer survivors. Methods Ninety-seven participants from a Dutch University Hospital’s exercise rehabilitation program were randomised to the COACH group (n = 46), receiving 6 months of remote coaching after completing the exercise program, or the CONTROL group (n = 50), receiving no additional intervention. Assessment of PA levels; sedentary time; aerobic capacity; muscle strength; fatigue; health-related quality of life (HRQoL); level of anxiety and depression; and return to work (RTW) rates were conducted at baseline (T0) and six months later (T1). Multiple linear regression was used for between-group statistical comparisons of all outcomes measures. Mean differences at T1 were estimated with corresponding 95% confidence intervals (95%CI). Results No significant between-group differences were observed for all outcomes at T1. An adjusted mean difference in weekly PA of 45 min (95%CI -50;140) was observed between the COACH group and the CONTROL group, favouring the COACH group, yet lacking statistical or clinical significance. Conclusions Our six-month remote coaching intervention did not notably improve PA levels; sedentary time; aerobic capacity; muscle strength; HRQoL; fatigue; anxiety and depression symptoms and RTW rates after participation in a supervised exercise oncology program. Although the participants who received coaching showed slightly higher levels of PA, these differences were not significant. More research is needed to identify patients in need for follow-up interventions following supervised exercise program and to investigate the effectiveness of remote coaching interventions in these patients. Trial registration Dutch Trial Register NL7729, registered 13 may 2019, https://trialsearch.who.int/Trial2.aspx?TrialID=NL7729

A Sucrose Mouth Rinse Does Not Improve 1-hr Cycle Time Trial Performance When Performed in the Fasted or Fed State

Carbohydrate mouth rinsing during exercise has been suggested to enhance performance of short (45–60 min) bouts of high-intensity ( > 75% VO2peak) exercise. Recent studies indicate that this performance enhancing effect may be dependent on the prandial state of the athlete. The purpose of this study was to define the impact of a carbohydrate mouth rinse on ~1-hr time trial performance in both the fasted and fed states. Using a double-blind, crossover design, 14 trained male cyclists (27 ± 6 years; 5.0 ± 0.5 W·kg-1) were selected to perform 4 time trials of ~1 hr (1,032 ± 127 kJ) on a cycle ergometer while rinsing their mouths with a 6.4% sucrose solution (SUC) or a noncaloric sweetened placebo (PLA) for 5 s at the start and at every 12.5% of their set amount of work completed. Two trials were performed in an overnight fasted state and two trials were performed 2 h after consuming a standardized breakfast. Performance time did not differ between any of the trials (fasted-PLA: 68.6 ± 7.2; fasted-SUC: 69.6 ± 7.5; fed-PLA: 67.6 ± 6.6; and fed-SUC: 69.0 ± 6.3 min; Prandial State × Mouth Rinse Solution p = .839; main effect prandial state p = .095; main effect mouth rinse solution p = .277). In line, mean power output and heart rate during exercise did not differ between trials. In conclusion, a sucrose mouth rinse does not improve ~1-hr time trial performance in well-trained cyclists when performed in either the fasted or the fed state

Fructose and Sucrose Intake Increase Exogenous Carbohydrate Oxidation during Exercise

Peak exogenous carbohydrate oxidation rates typically reach ~1 g∙min−1 during exercise when ample glucose or glucose polymers are ingested. Fructose co‐ingestion has been shown to further increase exogenous carbohydrate oxidation rates. The purpose of this study was to assess the impact of fructose co‐ingestion provided either as a monosaccharide or as part of the disaccharide sucrose on exogenous carbohydrate oxidation rates during prolonged exercise in trained cyclists. Ten trained male cyclists (VO2peak: 65 ± 2 mL∙kg−1∙min−1) cycled on four different occasions for 180 min at 50% Wmax during which they consumed a carbohydrate solution providing 1.8 g∙min−1 of glucose (GLU), 1.2 g∙min−1 glucose + 0.6 g∙min−1 fructose (GLU + FRU), 0.6 g∙min−1 glucose + 1.2 g∙min−1 sucrose (GLU + SUC), or water (WAT). Peak exogenous carbohydrate oxidation rates did not differ between GLU + FRU and GLU + SUC (1.40 ± 0.06 vs. 1.29 ± 0.07 g∙min−1, respectively, p = 0.999), but were 46% ± 8% higher when compared to GLU (0.96 ± 0.06 g∙min−1: p < 0.05). In line, exogenous carbohydrate oxidation rates during the latter 120 min of exercise were 46% ± 8% higher in GLU + FRU or GLU + SUC compared with GLU (1.19 ± 0.12, 1.13 ± 0.21, and 0.82 ± 0.16 g∙min−1, respectively, p < 0.05). We conclude that fructose co‐ingestion (0.6 g∙min−1) with glucose (1.2 g∙min−1) provided either as a monosaccharide or as sucrose strongly increases exogenous carbohydrate oxidation rates during prolonged exercise in trained cyclists

Casein Protein Processing Strongly Modulates Post-Prandial Plasma Amino Acid Responses In Vivo in Humans

Micellar casein is characterized as a slowly digestible protein source, and its structure can be modulated by various food processing techniques to modify its functional properties. However, little is known about the impact of such modifications on casein protein digestion and amino acid absorption kinetics and the subsequent post-prandial plasma amino acid responses. In the present study, we determined post-prandial aminoacidemia following ingestion of isonitrogenous amounts of casein protein (40 g) provided as micellar casein (Mi-CAS), calcium caseinate (Ca-CAS), or cross-linked sodium caseinate (XL-CAS). Fifteen healthy, young men (age: 26 ± 4 years, BMI: 23 ± 1 kg·m−2) participated in this randomized cross-over study and ingested 40 g Mi-Cas, Ca-CAS, and XL-CAS protein, with a ~1 week washout between treatments. On each trial day, arterialized blood samples were collected at regular intervals during a 6 h post-prandial period to assess plasma amino acid concentrations using ultra-performance liquid chromatography. Plasma amino acid concentrations were higher following the ingestion of XL-CAS when compared to Mi-CAS and Ca-CAS from t = 15 to 90 min (all p 0.05). In conclusion, cross-linked sodium caseinate is more rapidly digested when compared to micellar casein and calcium caseinate. Protein processing can strongly modulate the post-prandial rise in plasma amino acid bioavailability in vivo in humans