Influence of Carbohydrate Ingestion on Blood Glucose and Performance in Runners

1992 ◽  
Vol 2 (4) ◽  
pp. 317-327 ◽  
Author(s):  
Randall L. Wilber ◽  
Robert J. Moffatt
Keyword(s):  
Blood Glucose ◽  
Glucose Concentration ◽  
Perceived Exertion ◽  
Treadmill Exercise ◽  
Blood Glucose Concentration ◽  
Endurance Performance ◽  
Time To Exhaustion ◽  
Experimental Conditions ◽  
Double Blind ◽  
Carbohydrate Ingestion

Ten trained male runners performed a treadmill exercise test at 80%under two experimental conditions, carbohydrate (CHO, 7% carbohydrate) and placebo (P), to determine the effect of carbohydrate ingestion on endurance performance (treadmill run time), blood glucose concentration, respiratory exchange ratio (RER), and subjective ratings of perceived exertion (RPE). Treatment order was randomized and counterbalanced and test solutions were administered double-blind. Ingestion took place 5 min preexercise (250 ml) and at 15-min intervals during exercise (125 ml). Performance was enhanced by 29.4% (p~ 0.05) during CHO (115 ±25 min) compared to P (92 ± 27 min). Blood glucose concentration was significantly greater during CHO (5.6 ± 0.9 mM) relative to P (5.0 ±0.7 mM). There was a significant increase in mean RER following CHO ingestion (.94±.01) compared to P (.90±.01). Average RPE was significantly less during CHO (14.5±2.3) relative to P (15.4±2.4). These data suggest that time to exhaustion of high-intensity treadmill exercise is delayed as a result of carbohydrate ingestion and that this effect is mediated by favorable alterations in blood glucose concentration and substrate utilization.

Effects of Caffeine Ingestion on Exercise-induced Change during High-Intensity Intermittent Exercise

1995 ◽  
Vol 5 (1) ◽  
pp. 37-44 ◽  
Author(s):  
Isaiah Trice ◽  
Emily M. Haymes
Keyword(s):  
Blood Glucose ◽  
Perceived Exertion ◽  
Intermittent Exercise ◽  
Time To Exhaustion ◽  
Double Blind ◽  
Serum Free Fatty Acid ◽  
Caffeine Ingestion ◽  
Serum Free ◽  
Placebo Trial ◽  
Double Blind Design

In this study a double-blind design was used to determine the effect of caffeine on time to exhaustion and on associated metabolic and circulatory measures. Eight male subjects ingested either caffeine (5 mg/kg body weight) or a placebo 1 hr prior to exercise at 85-90% of maximum workload. Subjects were encouraged to complete three 30-min intermittent cycling periods at 70 rpm with 5 min rest between each. The exercise was terminated when the subject failed to complete three 30-min periods or failed to maintain 70 rpm for at least 15 s consecutively. Serum free fatty acids, glycerol, blood glucose, lactate, perceived exertion, heart rate, andcost were measured. The time to exhaustion was significantly longer during the caffeine trial than during the placebo trial. Serum free fatty acid levels were significantly different between trials. The decline in blood glucose levels was significantly less during the caffeine trial than during the placebo trial. There were no significant differences between trials for the other measures. It was concluded that caffeine increases time to exhaustion when trained subjects cycled intermittently at high levels of intensity.

scholarly journals Effects of two different doses of carbohydrate ingestion on taekwondo-related performance during a simulated tournament

2021 ◽  
Vol 18 (1) ◽  
Author(s):  
Alireza Naderi ◽  
Mohammad Hossein Samanipour ◽  
Amir Sarshin ◽  
Scott C. Forbes ◽  
Majid S. Koozehchian ◽  
...  
Keyword(s):  
Blood Glucose ◽  
Perceived Exertion ◽  
Low Dose ◽  
High Dose ◽  
Ratings Of Perceived Exertion ◽  
Three Solutions ◽  
Double Blind ◽  
Carbohydrate Ingestion ◽  
Gastrointestinal Discomfort ◽  
Different Doses

Abstract Background Carbohydrate (CHO) ingestion enhances exercise performance; however, the efficacy of CHO intake on repeated bouts of exercise simulating a taekwondo tournament is unknown. Therefore, the purpose was to compare the effects of two different doses of CHO on a sports-specific kicking test during a simulated taekwondo tournament compared to placebo (PLA). Methods In a double-blind, randomized-placebo controlled, cross-over trial, eleven junior male professional taekwondo athletes (age: 16 ± 0.8 years, body mass: 55.3 ± 7.3 kg) ingested one of three solutions: (i) high dose (C45): 45 g of CHO (60 g∙h− 1), (ii) low dose (C22.5): 22.5 g of CHO (30 g∙h− 1; both solutions containing 2:1 glucose:fructose), or a PLA immediately following each kicking test. The kicking test was repeated 5 times, separated by 45 mins of rest, simulating a typical taekwondo competition day. Ratings of perceived exertion (RPE) and gastrointestinal discomfort (GI) scores were collected immediately after, and blood glucose before each test. Results The results revealed that C45 and C22.5 did not improve total, successful, or percentage of successful kicks compared to PLA (p > 0.05). Blood glucose was significantly higher following both CHO conditions compared with PLA across all five tests (p < 0.05). There were no differences between treatments or across tests for RPE (p > 0.05). Conclusion CHO intake, independent of the dose, did not alter taekwondo kick performance during a simulated taekwondo tournament.

scholarly journals The Comparative Effect on Satiety and Subsequent Energy Intake of Ingesting Sucrose or Isomaltulose Sweetened Trifle: A Randomized Crossover Trial

Nutrients ◽  
2018 ◽  
Vol 10 (10) ◽  
pp. 1504 ◽  
Author(s):  
Fiona Kendall ◽  
Olivia Marchand ◽  
Jillian Haszard ◽  
Bernard Venn
Keyword(s):  
Blood Glucose ◽  
Energy Intake ◽  
Glucose Concentration ◽  
Crossover Trial ◽  
Blood Glucose Concentration ◽  
Area Under The Curve ◽  
Double Blind ◽  
Satiety Response ◽  
Diet Records ◽  
Significant Difference

The effect that blood glucose concentration has on feelings of satiety is unclear. Our aims were to assess satiety and subsequent energy intake following the ingestion of trifle sweetened with sucrose or isomaltulose whilst measuring plasma glucose concentration to confirm glycemic differences between trifles. Seventy-seven healthy adults participated in a double-blind crossover trial where trifle sweetened with sucrose or isomaltulose was consumed on separate days with a two-week washout. Blood was sampled at the baseline, 1 and 2 h postprandially, and satiety assessed using visual analogue scales (VAS). Weighed diet records were taken on test days. A statistically significant difference in blood glucose concentration between trifles was found at 60 min following consumption, with the isomaltulose trifle having a 0.69 mmol/L (95% confidence interval: −1.07, −0.31) lower concentration when compared with the sucrose trifle. Mean satiety response by area-under-the-curve (AUC) was not significantly different between trifles. Mean (SD) appetite scores for the sucrose and isomaltulose trifles were 4493 (2393) and 4527 (2590) mm·min, respectively, with a between trifle difference of −9 (95% CI: −589, 572) mm·min. Mean (SD) energy intake for the remainder of the day following trifle consumption was 3894 kJ (1950 kJ) and 3530 kJ (1926 kJ) after the sucrose and isomaltulose trifles, respectively, and was not significantly different (p = 0.133). The differing glycemic response to trifle was not related to satiety or to subsequent energy intake.

Effects of Coenzyme Athletic Performance System as an Ergogenic Aid on Endurance Performance to Exhaustion

1992 ◽  
Vol 2 (3) ◽  
pp. 272-286 ◽  
Author(s):  
Ian P. Snider ◽  
Terry L. Bazzarre ◽  
Scott D. Murdoch ◽  
Allan Goldfarb
Keyword(s):  
Blood Glucose ◽  
Athletic Performance ◽  
Performance Test ◽  
Endurance Performance ◽  
Crossover Design ◽  
Time To Exhaustion ◽  
Double Blind ◽  
Placebo Trial ◽  
Performance System ◽  
The Mean

This study examined the effects of the Coenzyme Athletic Performance System (CAPS) on endurance performance to exhaustion. CAPS contains 100 mg coenzyme Q10,500 mg cytochrome C, 100 mg inosine, and 200 IU vitamin E. Eleven highly trained male triathletes were given three daily doses of either CAPS or placebo (dicalcium phosphate) for two 4-week periods using a double-blind crossover design. A 4-week washout period separated the two treatment periods. An exhaustive performance test, consisting of 90 minutes of running on a treadmill (70%) followed by cycling (70%) until exhaustion, was conducted after each treatment period. The mean (±SEM) time to exhaustion for the subjects using CAPS (223 ±17 min) was not significantly different (p=0.57) from the placebo trial (215 ±9 min). Blood glucose, lactate, and free fatty acid concentrations at exhaustion did not differ between treatments (p< 0.05). CAPS had no apparent benefit on exercise to exhaustion.

scholarly journals Caffeine and sodium bicarbonate supplementation alone or together improve karate performance

2019 ◽  
Vol 16 (1) ◽  
Author(s):  
Sajjad Rezaei ◽  
Kazem Akbari ◽  
Daniel E. Gahreman ◽  
Amir Sarshin ◽  
Montassar Tabben ◽  
...  
Keyword(s):  
Sodium Bicarbonate ◽  
Athletic Performance ◽  
Perceived Exertion ◽  
Controlled Trial ◽  
Physiological Responses ◽  
Time To Exhaustion ◽  
Experimental Conditions ◽  
Double Blind ◽  
Rate Of Perceived Exertion ◽  
Ergogenic Effects

Abstract Background The ergogenic properties of acute caffeine (CAF) and sodium bicarbonate (NaHCO3) ingestion on athletic performance have been previously investigated. However, each sport has unique physiological and technical characteristics which warrants optimizing supplementations strategies for maximizing performance. This study examined the effects of CAF and NaHCO3 ingestion on physiological responses and rate of perceived exertion during a Karate-specific aerobic test (KSAT) in competitive karatekas. Methods In a double-blind, crossover, randomized placebo-controlled trial, eight Karatekas underwent five experimental conditions including control (CON), placebo (PLA), CAF, NaHCO3, and CAF + NaHCO3 before completing KSAT. Capsules containing 6 mg/kg BW CAF were consumed 50 min prior to a KSAT whilst 0.3 g/kg BW NaHCO3 was consumed for 3 days leading to and 120, 90, and 60 min prior to a KSAT. Time to exhaustion (TTE), rate of perceived exertion (RPE), and blood lactate (BL) were measured before, immediately after and 3 min following KSAT. Results TTE was significantly greater following CAF, NaHCO3, and CAF + NaHCO3 consumption compared to PLA and CON. However, the differences between CAF, NaHCO3, and CAF + NaHCO3 were not statistically significant (p > 0.05). BL increased significantly from baseline to immediately after and 3 min following KSAT in all conditions (p < 0.01), while RPE at the end of KSAT was not significantly different between conditions (p = 0.11). Conclusions Karate practitioners may benefit from the ergogenic effects of CAF and NaHCO3 when consumed separately or together.

Acute ingestion of hydrogen-rich water does not improve incremental treadmill running performance in endurance-trained athletes

2020 ◽  
Vol 45 (5) ◽  
pp. 513-519 ◽  
Author(s):  
Cheong Hwa Ooi ◽  
Siew Kit Ng ◽  
Eshaifol Azam Omar
Keyword(s):  
Oxygen Uptake ◽  
Maximal Oxygen Uptake ◽  
Perceived Exertion ◽  
Controlled Trial ◽  
Physiological Responses ◽  
Endurance Performance ◽  
Treadmill Running ◽  
Time To Exhaustion ◽  
Double Blind ◽  
Acute Ingestion

There is emerging evidence that hydrogen-rich water (H2-water) has beneficial effects on the physiological responses to exercise. However, few studies investigate its ergogenic potential. This randomized controlled trial examined the effects of H2-water ingestion on physiological responses and exercise performance during incremental treadmill running. In a double-blind crossover design, 14 endurance-trained male runners (age, 34 ± 4 years; body mass, 63.1 ± 7.2 kg; height, 1.72 ± 0.05 m) were randomly assigned to ingest 2 doses of 290-mL H2-water or placebo on each occasion. The first bolus was given before six 4-min submaximal running bouts, and the second bolus was consumed before the maximal incremental running test. Expired gas, heart rate (HR), and ratings of perceived exertion (RPE) were recorded; blood samples were collected at the end of each submaximal stage and post maximal running test. Cardiorespiratory responses, RPE, and blood gas indices were not significantly different at each submaximal running intensity (range: 34%–91% maximal oxygen uptake) between H2-water and placebo trials. No statistical difference was observed in running time to exhaustion (618 ± 126 vs. 619 ± 113 s), maximal oxygen uptake (56.9 ± 4.4 vs. 57.1 ± 4.7 mL·kg−1·min−1), maximal HR (184 ± 7 vs. 184 ± 7 beat·min−1), and RPE (19 ± 1 vs. 19 ± 1) in the runners between the trials. The results suggest that the ingestion of 290 mL of H2-water before submaximal treadmill running and an additional dose before the subsequent incremental running to exhaustion were not sufficiently ergogenic in endurance-trained athletes. Novelty Acute ingestion of H2-water does not seem to be ergogenic for endurance performance. A small dose of H2-water does not modulate buffering capacity during intense endurance exercise in athletes.

Sign in / Sign up

Export Citation Format

Share Document