scholarly journals Is Hemoglobin Mass at Age 16 a Predictor for National Team Membership at Age 25 in Cross-Country Skiers and Triathletes?

2021 ◽  
Vol 3 ◽  
Author(s):  
Jon Peter Wehrlin ◽  
Thomas Steiner
Keyword(s):  
Carbon Monoxide ◽  
Body Weight ◽  
Endurance Performance ◽  
Important Predictor ◽  
Endurance Athletes ◽  
Young Athletes ◽  
High Performing ◽  
National Team ◽  
Cross Country ◽  
Hemoglobin Mass

We recently measured the development of hemoglobin mass (Hbmass) in 10 Swiss national team endurance athletes between ages 16–19. Level of Hbmass at age 16 was an important predictor for Hbmass and endurance performance at age 19. The aim was to determine how many of these young athletes were still members of Swiss national teams (NT) at age 25, how many already terminated their career (TC), and whether Hbmass at ages 16 and 19 was different between the NT and TC group. We measured Hbmass using the optimized carbon monoxide re-breathing technique in 10 high-performing endurance athletes every 0.5 years beginning at age 16 and ending at age 19. At age 25, two athletes were in the NT group and eight athletes in the TC group. Mean absolute, body weight-, and lean body mass (LBM) related Hbmass at age 16 was 833 ± 61 g, 13.7 ± 0.2 g/kg and 14.2 ± 0.2 g/kg LBM in the NT group and 742 ± 83 g, 12.2 ± 0.7 g/kg and 12.8 ± 0.8 g/kg LBM in the TC group. At age 19, Hbmass was 1,042 ± 89 g, 14.6 ± 0.2 g/kg and 15.4 ± 0.2 g/kg LBM in the NT group and 863 ± 109 g, 12.7 ± 1.1 g/kg and 13.5 ± 1.1 g/kg LBM in the TC group. Body weight- and LBM related Hbmass were higher in the NT group than in the TC group at ages 16 and 19 (p < 0.05). These results indicate, that Hbmass at ages 16 and 19 possibly could be an important predictor for later national team membership in endurance disciplines.

Live high-train low for 24 days increases hemoglobin mass and red cell volume in elite endurance athletes

2006 ◽  
Vol 100 (6) ◽  
pp. 1938-1945 ◽  
Author(s):  
Jon Peter Wehrlin ◽  
Peter Zuest ◽  
Jostein Hallén ◽  
Bernard Marti
Keyword(s):  
Cell Volume ◽  
Sea Level ◽  
Endurance Athletes ◽  
Control Group ◽  
Red Cell ◽  
Red Cell Volume ◽  
National Team ◽  
Before And After ◽  
Hemoglobin Mass ◽  
And Performance

The effect of live high-train low on hemoglobin mass (Hbmass) and red cell volume (RCV) in elite endurance athletes is still controversial. We expected that Hbmass and RCV would increase, when using a presumably adequate hypoxic dose. An altitude group (AG) of 10 Swiss national team orienteers (5 men and 5 women) lived at 2,500 m (18 h per day) and trained at 1,800 and 1,000 m above sea level for 24 days. Before and after altitude, Hbmass, RCV (carbon monoxide rebreathing method), blood, iron, and performance parameters were determined. Seven Swiss national team cross-country skiers (3 men and 4 women) served as “sea level” (500–1,600 m) control group (CG) for the changes in Hbmass and RCV. The AG increased Hbmass (805 ± 209 vs. 848 ± 225 g; P < 0.01) and RCV (2,353 ± 611 vs. 2,470 ± 653 ml; P < 0.01), whereas there was no change for the CG (Hbmass: 849 ± 197 vs. 858 ± 205 g; RCV: 2,373 ± 536 vs. 2,387 ± 551 ml). Serum erythropoietin ( P < 0.001), reticulocytes ( P < 0.001), transferrin ( P < 0.001), soluble transferrin receptor ( P < 0.05), and hematocrit ( P < 0.01) increased, whereas ferritin ( P < 0.05) decreased in the AG. These changes were associated with an increased maximal oxygen uptake (3,515 ± 837 vs. 3,660 ± 770 ml/min; P < 0.05) and improved 5,000-m running times (1,098 ± 104 vs. 1,080 ± 98 s; P < 0.01) from pre- to postaltitude. Living at 2,500 m and training at lower altitudes for 24 days increases Hbmass and RCV. These changes may contribute to enhance performance of elite endurance athletes.

Well-Trained Endurance Athletes’ Knowledge, Insight, and Experience of Caffeine Use

2007 ◽  
Vol 17 (4) ◽  
pp. 328-339 ◽  
Author(s):  
Ben Desbrow ◽  
Michael Leveritt
Keyword(s):  
Body Weight ◽  
Standard Deviation ◽  
Side Effects ◽  
Endurance Performance ◽  
Cross Sectional Study ◽  
Endurance Athletes ◽  
Sectional Study ◽  
Journal Articles ◽  
Cross Sectional ◽  
Food Items

This descriptive cross-sectional study assessed the perceptions, knowledge, and experiences of caffeine use by athletes competing at the 2005 Ironman Triathlon World Championships. Questionnaires were distributed to 140 athletes (105 men and 35 women, 40.3 ± 10.7 y old) representing 16 countries during prerace registration. A large proportion (73%) of these endurance athletes believe that caffeine is ergogenic to their endurance performance, and 84% believe it improves their concentration. The most commonly reported positive caffeine experiences related to in-competition use of cola drinks (65%) and caffeinated gels (24%). The athletes’ ability to accurately quantify the caffeine content of common food items was limited. The most popular sources of caffeine information were self-experimentation (16%), fellow athletes (15%), magazines (13%), and journal articles (12%). Over half the athletes (53%) could not identify an amount of caffeine required to improve their triathlon performance. Mean (± standard deviation) suggested doses were 3.8 (± 3) mg/kg body weight. Few side effects associated with taking caffeine during exercise were reported.

The Efficacy of Carbohydrate Supplementation and Chronic High-Carbohydrate Diets for Improving Endurance Performance

1999 ◽  
Vol 9 (1) ◽  
pp. 92-115 ◽  
Author(s):  
Kevin Allen Jacobs ◽  
W. Michael Sherman
Keyword(s):  
Body Weight ◽  
Endurance Performance ◽  
Endurance Athletes ◽  
Moderate Intensity ◽  
Review Of The Literature ◽  
Moderate Intensity Exercise ◽  
Carbohydrate Supplementation ◽  
Dietary Recommendation ◽  
High Carbohydrate ◽  
And Performance

Carbohydrate (CHO) is the body's most limited fuel and the most heavily metabolized during moderate-intensity exercise. For this reason it is recommended that endurance athletes consume a high-CHO diet (8-10 g CHO ⋅ kg body weight−1 ⋅ day−1) to enhance training and performance. A review of the literature supports the benefits of CHO supplementation on endurance performance. The benefits of chronic high-CHO diets on endurance performance are not as clear. Recent evidence suggests that a high-CHO diet may be necessary for optimal adaptations to training. However, the paucity of data in this area precludes any concrete conclusions. The practicality of high-CHO diets is not well understood. The available evidence would indicate that a high-CHO diet is the best dietary recommendation for endurance athletes.

An Assessment of Carbohydrate Intake in Collegiate Distance Runners

1995 ◽  
Vol 5 (3) ◽  
pp. 206-211 ◽  
Author(s):  
Jill A. Tanaka ◽  
Hirofumi Tanaka ◽  
William Landis
Keyword(s):  
Body Weight ◽  
Muscle Glycogen ◽  
Endurance Athletes ◽  
Training Period ◽  
Dietary Recommendations ◽  
Distance Runners ◽  
Daily Amount ◽  
The Mean ◽  
Feeding Regimen ◽  
Cross Country

To determine the extent to which well-trained endurance athletes practice the dietary recommendations for maximizing muscle glycogen resynthesis, collegiate cross-country runners (14 males and 10 females) kept 4-day dietary and activity records during a training period and a competitive period in the regular cross-country season. The mean running mileages for men and women were 16.0 ± 1.0 and 10.7 ± 0.6 km/day during the training period and 14.6 ± 0.8 and 8.7 ± 0.5 km/day during the competitive period, respectively. Males reported adequate energy intake in both phases, whereas females fell short of the RDA. However, the percentage of calories from carbohydrate was found to be inadequate (< 60%) for male runners. Although female runners derived 65-67% of calories from carbohydrate, the daily amount of carbohydrate taken was insufficient (< 10 g/kg body weight). Carbohydrate was ingested immediately postexercise approximately 50% of the time or less, with even far less taken in suggested quantities (−1 g carbohydrate/kg body weight). There were no significant differences in dietary trends between training and competitive phases. The results suggest that these endurance athletes were not practicing the recommended feeding regimen for optimal muscle glycogen restoration.

scholarly journals Efficacy of Popular Diets Applied by Endurance Athletes on Sports Performance: Beneficial or Detrimental? A Narrative Review

Nutrients ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 491
Author(s):  
Aslı Devrim-Lanpir ◽  
Lee Hill ◽  
Beat Knechtle
Keyword(s):  
Gastrointestinal Symptoms ◽  
Endurance Performance ◽  
Endurance Athletes ◽  
Intermittent Fasting ◽  
Nutritional Strategy ◽  
Current Perspective ◽  
Vegetarian Diets ◽  
Fat Diets ◽  
The Impact ◽  
Harsh Conditions

Endurance athletes need a regular and well-detailed nutrition program in order to fill their energy stores before training/racing, to provide nutritional support that will allow them to endure the harsh conditions during training/race, and to provide effective recovery after training/racing. Since exercise-related gastrointestinal symptoms can significantly affect performance, they also need to develop strategies to address these issues. All these factors force endurance athletes to constantly seek a better nutritional strategy. Therefore, several new dietary approaches have gained interest among endurance athletes in recent decades. This review provides a current perspective to five popular diet approaches: (a) vegetarian diets, (b) high-fat diets, (c) intermittent fasting diets, (d) gluten-free diet, and (e) low fermentable oligosaccharides, disaccharides, monosaccharides and polyols (FODMAP) diets. We reviewed scientific studies published from 1983 to January 2021 investigating the impact of these popular diets on the endurance performance and health aspects of endurance athletes. We also discuss all the beneficial and harmful aspects of these diets, and offer key suggestions for endurance athletes to consider when following these diets.

scholarly journals Liver-Metabolizing Genes and Their Relationship to the Performance of Elite Spanish Male Endurance Athletes; a Prospective Transversal Study

2019 ◽  
Vol 5 (1) ◽  
Author(s):  
David Varillas Delgado ◽  
Juan José Tellería Orriols ◽  
Carlos Martín Saborido
Keyword(s):  
Binary Logistic Regression ◽  
Endurance Performance ◽  
Endurance Athletes ◽  
Genetic Profile ◽  
Glutathione S Transferase ◽  
Binary Logistic Regression Model ◽  
Genotypic Distribution ◽  
Endurance Runner ◽  
Cytochrome P450 Family ◽  
First Time

Abstract Background The genetic profile that is needed to define an endurance athlete has been studied during recent years. The main objective of this work is to approach for the first time the study of genetic variants in liver-metabolizing genes and their role in endurance performance by comparing the allelic and genotypic frequencies in elite endurance athletes to the non-athlete population. Methods Genotypic and allelic frequencies were determined in 123 elite endurance athletes (75 professional road cyclists and 48 endurance elite runners) and 122 male non-athlete subjects (sedentary). Genotyping of cytochrome P450 family 2 subfamily D member 6 (CYP2D6 rs3892097), glutathione-S transferase mu isoform 1 (GSTM1), glutathione S-transferase pi (GSTP rs1695) and glutathione S-transferase theta (GSTT) genes was performed by polymerase chain reaction (PCR). The combination of the polymorphisms for the “optimal” polygenic profile has been quantified using the genotype score (GS). Results Statistical differences were found in the genetic distributions between elite endurance athletes and non-athletes in CYP2D6 (p < 0.001) and GSTT (p = 0.014) genes. The binary logistic regression model showed a favourable OR (odds ratio) of being an elite endurance runner against a professional road cyclist (OR: 2.403, 95% CI: 1.213–4.760 (p = 0.002)) in the polymorphisms studied. Conclusions Genotypic distribution of liver-metabolizing genes in elite endurance athletes is different to non-athlete subjects, with a favourable gene profile in elite endurance athletes in terms of detoxification capacity.

Relationship between total hemoglobin mass and competitive performance in endurance athletes

2019 ◽  
Vol 59 (3) ◽  
Author(s):  
Irina E. Zelenkova ◽  
Sergey V. Zotkin ◽  
Pavel V. Korneev ◽  
Sergey V. Koprov ◽  
Alexander A. Grushin
Keyword(s):  
Endurance Athletes ◽  
Competitive Performance ◽  
Total Hemoglobin ◽  
Hemoglobin Mass

Autonomic and Perceptual Responses to Induction of a Ketogenic Diet in Free-Living Endurance Athletes: A Randomized, Crossover Trial

2020 ◽  
pp. 1-7
Author(s):  
Ed Maunder ◽  
Deborah K. Dulson ◽  
David M. Shaw
Keyword(s):  
Heart Rate ◽  
Heart Rate Variability ◽  
Exercise Capacity ◽  
Ketogenic Diet ◽  
Physiological Stress ◽  
Endurance Performance ◽  
Endurance Athletes ◽  
Recovery Stress ◽  
Individual Level ◽  
Dietary Shift

Purpose: Considerable interindividual heterogeneity has been observed in endurance performance responses following induction of a ketogenic diet (KD). It is plausible that a physiological stress response in the period following the dramatic dietary shift associated with transition to a KD may explain this heterogeneity. Methods: In a randomized, crossover study design, 8 trained male runners completed an incremental exercise test and ran to exhaustion at 70%VO2max before and after a 31-day rigorously controlled habitual diet or KD intervention, and recorded heart rate variability (root mean square of the sum of successive differences in R–R intervals [rMSSD]) upon waking each morning along with the recovery–stress questionnaire for athletes each week. Data were analyzed using linear mixed models. Results: A significant reduction in rMSSD was observed in the KD (−9.77 [4.03] ms, P = .02), along with an increase in day-to-day variability in rMSSD (2.1% [1.0%], P = .03). The reduction in rMSSD in the KD for the subgroup of individuals exhibiting impaired exercise capacity following induction of the KD approached significance (Δ −22 [15] ms, P = .06, N = 4); whereas no effect was observed in those who exhibited unchanged exercise capacity (Δ 5 [18] ms, P = .61, N = 4). No main effects were observed for recovery–stress questionnaire for athletes. Conclusions: Our data suggest those working with endurance athletes transitioning onto a KD may consider using noninvasive, inexpensive resting heart rate variability measures to gain individual-level insights into the likely short-term effects on exercise capacity.

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