Arab Journal of Nutrition and Exercise (AJNE) | AJNE: Vol 2, No 1 (2017) | pages: 23-39

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1. Introduction

Dietary supplement use is expanding among athletes who are experimenting with a variety of substances, even illegal ones as to reach a competitive edge [15,25,33]. Ranges of age of cyclists vary and some athletes remain highly competitive into their 40s, although it is likely that performance peaks before 35 years of age. Ageing performance declines in similar way among several sports, yet, there are older, competitive and athletically ambitious athletes, called veterans or masters. Most likely to be founded positive for illegal substances are non-professional cyclists aged 30 to 50 years. Therefore, cycling is one of the most energy-expensive sports and the use of ergogenic aids is most popular [33].

Maintaining performance during endurance exercise is dependent on a variety of dietary factors, such as energy and water balance, appropriate macro and micro-nutrient intake. [19]. Many athletes do not seem to cover their energy demands [27] and are often leaded to limited energy supply [82,59,45,55].

The main nutrient that can improve endurance and reduce fatigue is carbohydrates [20,72], through maintaining blood glucose levels, CHO oxidation rates and preventing glycogen depletion [13]. Athletes consuming high proportion of carbohydrates had a better performance compared to others who consumed moderate quantities [14,38,16]. However, carbohydrates' consumption before and during brief exercise cannot act favorably [13].

Thus, carbohydrates act as ergogenic aid in endurance sports as cycling [13]. Other preferred ergogenic aids of cyclists, except for carbohydrates, are: proteins, caffeine, creatine, sodium bicarbonate beta-alanine and nitrates [18].

Sport beverages gained popularity as they attribute to both energy-giving and hydration- and electrolyte status maintaining in endurance performance. Experienced and older athletes are more likely to prefer sport beverages and to follow a drinking schedule during exercise [88,58]. Energy drinks seem, also, to have a positive effect on performance [78] through hydration and energy supply [37,24] and fatigue reduction [2,14] and thus, they are of vital importance for endurance sports [39]. Elements contained in energy drinks are ginseng, guarana, taurine and caffeine which are not dangerous when received in recommended doses [17].

Caffeine can improve performance [7,79] acting through an enhance in central nervous system and in fat oxidation rate [68,86]. There are many studies suggesting that caffeine improves power and endurance compared to placebo or other supplements [26,57,81,35,54,29]. A moderate dose of caffeine significantly improves performance [44,84], while very low doses of caffeine cannot be ergogenic [6] and a high dose may act against performance [48]. Chronic ingestion of low caffeine doses develops tolerance in low-caffeine consumers. Therefore, individuals with low-habitual intakes should refrain from chronic caffeine supplementation as to maximize performance benefits from acute caffeine ingestion [6].

American Dietetic Association, Dietitians of Canada and the American College of Sports state that anthropometric characteristics influence performance. Body composition and weight are the two main factors that can be manipulated and contribute to potential for athletic success. Specifically, body weight can add to an athlete's endurance, speed and power, while body composition improves agility, strength and appearance. However body mass and composition cannot solely predict the progression of a career and there is no optimal competitive body weight or composition for any sport or athletic group [74,86]. Thus, body weight and composition are important indicators of physical fitness and can improve performance [3,42]. Low body fat and high muscle mass levels are linked with better sports achievements [42].

Mediterranean diet contains an abundance of bioactive food constituents like complex carbohydrates, fibers, vegetable proteins, unsaturated fas, minerals, vitamins, polyphenols and phytosterols that can interact synergistically and affect beneficially metabolic pathways, lowering the risk of cardiometabolic disorders, cognitive decline and all-cause mortality [80,47,75]. Endurance exercise generates oxidative stress and acute inflammation [12], whereas Mediterranean diet improves immune system function [50], mitigates inflammation and enhances performance, recovery and injury repair [76]. For these reasons adherence to Mediterranean diet is essential for athletes following an exhaustive training program such as cyclists. Meddiet score is a useful tool that can evaluate the adherence to Mediterranean dietary pattern [60].

There is limited data regarging nutrition practices and energy needs of elite athletes, especially in Greece [31,67,66,64,63,32,61]. To the best of our knowledge there is no study on the effect of ergogenic aids and meddiet score on Greek cyclists' performance. Therefore, the goals of the present study were to record the prevalence and the type of supplement use among cyclists and to estimate the effect of caffeine, carbohydrates, energy drinks and meddiet score on 200m and 4km cycling time-trial performance in a Greek sample.

2. Methods

2.1. Population Sample

Fifty male cyclists aged 32 ± 20 years participated in this randomized double-blind study. Athletes responded to an announcement for this study posted in different cycling local training teams. Fifty cyclists fulfilled the inclusion criteria of the study (having a background for at least 6 sequentially years of training, having competed in the Greek National Championship and not having any orthopaedic/neuromuscular, restraining problems or taking any steroid supplements). The study was carried out in Thessaloniki, Greece, in 2015.

Participants have given their written consent prior to entering the study, which received approval by the Ethics Committee of the Alexander Technological Educational Institute of Thessaloniki, Greece, and is in accordance with the Declaration of Helsinki.

2.2. Procedures

The present study was divided into three meetings.

2.2.1. Anthropometric Characteristics and Body Composition

The first meeting took place one day before the first cycling trial. In the first meeting, an experienced dietitian performed all anthropometric measurements in the morning, after an overnight fasting and all athletes were in minimal clothing. Body weight was measured with the use of a calibrated digital scale with an accuracy of ±100g (Tanita 545N) and body height to the nearest 0.5 cm using a stadiometer, with an accuracy of 0.5 cm (SECA 220). Body mass index (BMI) was calculated as body weight divided by the square of height (kg/m2). Body composition was estimated with the method of bioelectrical impedance analysis using portable bioelectrical impedance device (Tanita 545N). All cyclists were informed about the protocol for body composition assessment. They abstained from any type of exercise one day prior to measurement. Cyclists stood bare feet on the device, maintaining contact with their feet on electrodes and instructed to grasp the retractable handle as to have contact on electrodes with their palms.

2.2.2. Questionnaires

During the first meeting, a qualified dietitian instructed all subjects to complete the meddiet Score [60] and a questionnaire that has been evaluated in a previous study from our lab, regarding their ergogenic supplements' consumption (ie. Type of supplement, reasons for their use, source of information) [62,65].

2.2.3. Cycling Trials

In the second meeting, all athletes completed a field based 200m speed race. In the third meeting, they completed a field based 4km endurance race. Their performance was evaluated according to the ergogenic supplement that each athlete had received, and their meddiet score.

2.3. Statistical Analysis

For the statistical analysis and the elaboration of the results, the computer package SPSS v20 was used. Results are presented as means ± standard deviation and/or percentages where appropriate. The level of significance was set at p<0.05.

3. Results

A total of 50 male cyclists participated in the study, with their age varying from 15 to 50 years.

Table 1 depicts anthropometric characteristics of our sample.

Table 1

Anthropometric characteristics.


Anthropometric characteristics Min Max Mean SD
Weight (kg) 51.00 123.00 74.6 12.2
Height (m) 1.61 1.92 1.77 0.08
Body Fat (%) 5.80 36.40 15.82 8.33
Body Water (%) 50.20 69.10 58.51 4.15
BMI (kg/m2) 19.00 33.40 23.65 2.74

Frequency of training is presented in table 2. Each session lasted 1.5h, approximately.

Table 2

Frequency of training.


Sessions per week N Percentage
1-3 / week 13 26%
3-6 / week 24 47%
6-7 / week 14 27%

Cyclists used 10 different nutritional supplements (Table 3). 44% of the cyclists consumed energy drinks, while caffeine, carbohydrates, proteins and vitamins were used by 24%, 30%, 30% and 22%, respectively. Also, it is worth to mention that 38% of the athletes did not take any supplement in order to improve their performance.

Table 3

Supplements consumption.


Ergogenic aids N Percentage
Energy drinks 22 44%
Athletic drinks 9 18%
Caffeine 12 24%
Carbohydrates 15 30%
Protein / Acids 15 30%
Sodium 1 2%
Vitamins / Minerals 11 22%
Creatine 2 4%
Carnitine 3 6%
Glutamine 4 8%
Nothing 19 38%

Endurance and speed performances were improved with caffeine consumption when compared to no consumption (7.42 ± 3.92 min vs 12.5 ± 3.16 min, p < 0.001 and 20.75 ± 15.69 sec vs 34.07 ± 16.25 sec, p < 0.05, respectively), as well as with energy drinks' consumption (8.77 ± 4.15 min vs 13.25 ± 2.47 min, p < 0.001 and 20.35 ± 14.08 sec vs 39.14 ± 14.38 sec, p < 0.001, respectively). Carbohydrates' intake improved performance in the endurance test (7.60 ± 3.72 min vs 12.86 ± 2.92 min, p < 0.001), but did not have a positive influence in the speed test (25.73 ± 18.68 sec vs 33.08 ± 15.95 sec, p > 0.05) (Table 4).

Table 4

Performance in endurance and speed tests according to supplements' consumption.


<Supplements' consumption N Endurance performance (minutes) Speed Performance (seconds)
Yes 12 7.42 ± 3.92 (p = 0.001) 20.75 ± 15.69 (p = 0.016)
Caffeine No 38 12.5 ± 3.16 (p = 0.001) 34.07 ± 16.25 (p = 0.016)
Yes 15 7.60 ± 3.72 (p = 0.001) 25.73 ± 18.68 (p = 0.163)
Carbohydrates No 35 12.86 ± 2.92 (p = 0.001) 33.08 ± 15.95 (p = 0.163)
Yes 22 8.77 ± 4.15 (p = 0.001) 20.35 ± 14.08 (p = 0.001)
Energy drinks No 28 13.25 ± 2.47 (p = 0.001) 39.14 ± 14.38 (p = 0.001)
<Total cyclists regardless supplement consumption 50 11.28 ± 3.97 (p = 0.001) 30.88 ± 16.96 (p = 0.001)

Adherence to the Mediterranean diet was assessed by the meddiet Score (theoretical range: 0-55). Forty-three out of 50 cyclists had a median score regarding the adherence to the Mediterranean diet (score 28-41), while six cyclists had low scores (score 14-27) and only 1 cyclist had great adherence to the Mediterranean diet. Level of adherence to the Mediterranean diet played no significant role in endurance (p = 0.563) and speed test results (p = 0.462) (Table 5).

Table 5

Performance in endurance and speed tests according to adherence to the Mediterranean diet.


Meddiet Score N Performance of resistance (minutes) Performance of speed (seconds)
Score 14-27 6 12.50 ± 3.56 (p = 0.563) 30.63 ± 18.63 (p = 0.462)
Score 28-41 43 11.05 ± 4.06 (p = 0.563) 30.42 ± 16.84 (p = 0.462)
Score 42-55 1 14.00 (p = 0.563) 32.00 (p = 0.462)

4. Discussion

As it regards, the anthropometric variables, Greek cyclists had a mean BMI value of 23.65 ± 2.74 and a mean body fat percentage of 15.82 ± 8.33. Cyclists of the present study had higher values in both BMI and body fat levels compared to 6 professional road cyclists participated in the Tour of Andalusia, a 4stage race covering 647.6 Km [77]. In comparison to other endurance sports, Greek cyclists presented similar BMI and body fat levels with Greek male cross country skiers [63], with the New Zealand Ironman triathlon male athletes [41] and with the non-professional male triathletes, that participated in the Daurada Extreme Man Salou-Costa triathlon [4].

According to [42], high body fat affects negatively cyclists' performance and increased BMI acts against racing effort [40,5]. In [85] investigated the effects of training and anthropometric characteristics on male marathon and ultra-marathon performance and found that body fat levels above 15% can negatively affect performance.

In our sample, most cyclists trained less than 9 hours per week, which is less than the appropriate training load that maximizes athletes' performance, according to [73].

In the present study, 62% of the cyclists took supplements in order to improve their performance. A total of 44% of the cyclists consumed energy drinks, while caffeine, carbohydrates and proteins and vitamins were used by 24% 30%, 30% and 22%, respectively. A small percentage of Greek cyclists consumed carnitine, which lacks scientific evidence for boosting performance [10,86].

A recent study of [87] in 778 Dutch athletes with elite status, reported that when athletes received dietary counseling had a higher consumption of vitamin D, isotonic drinks, recovery drinks, energy bars, isotonic sports drinks with protein, probiotics, beta-alanine and sodium bicarbonate. In contrast when they did not have any counseling, they preferred combined vitamin supplements, calcium, energy gels BCAA/ other amino acids and energy drinks.

Previous studies reported that dietary supplements are used by athletes as to allow them to improve performance through harder training, quicker recover (Ziegler et al., 2003), [52] and prevention from injuries and illness (Ziegler et al., 2003), [69]. The prevalence of dietary supplementation among elite athletes falls in the range of 62–91% for athletes under 20 years of age [56,23,9,22], and 51–99% for elite adult athletes [36,23,9,21,83,87].

The use of dietary supplements is alarming as athletes consume different supplements [69,21,22] that can interact with each other [10,71] or provoke negative consequences such as allergic reactions or toxicity in large doses (Lawson et al., 2007), [71] or have as a result misinformation [49] and inadvertent product contamination [28]. There is lack in universal regulation and consequently there are differences across countries in the ergogenic aids' practice and approach. There is often a gap between scientific evidence and marketing hype [71].

Regarding the impact of supplementation on cycling performance, the present study concluded that energy drinks' consumption was associated with better performance in both endurance (p = 0.001) and speed races (p = 0.001), a finding which comes in agreement with other studies in cyclists showing that performance was improved with energy drinks comparing to placebo [37,24][1]. We should bare in mind that energy drinks should be consumed in rational proportions as to act in favor of exercise, otherwise they may become dangerous, causing hypertension, cardiac dysrhythmias, tachycardia or heart failure [17,24,71].

Accordingly, in the present study, carbohydrates showed a positive impact on athletic performance during the endurance test (p = 0.001), similar with other experimental studies in cyclists [46,20]. However, regarding the speed test of 200m, the consumption of carbohydrates from our cyclists did not have any ergogenic benefit (p = 0.163), which is suggested by [13].

Finally, our results indicated that caffeine consumption improved performance in both endurance and speed races, when comparing to other cyclists who did not consume caffeine. The ergogenic impact of caffeine is supported by a plethora of studies [26,35,8,30,34]. However, caffeine intake can provoke side effects such as headache, hypertension, tachycardia and gastrointestinal upset [51,11] and acts differently in every athlete [70].

Regarding the results from the meddiet Score, 86% of our cyclists had a median adherence to the Mediterranean diet, whereas 12% had a low adherence. This finding is in accordance with a study in 45 young Spanish cyclists, reporting that approximately 20% of them did not comply to the Mediterranean diet, confirming a gradual abandoning of the Mediterranean Diet [76].

In the present study, there was no significant effect of the Mediterranean diet on speed or endurance cycling performance. To the best of our knowledge there is no study estimating the effect of Mediterranean diet on sport performance.

5. Conclusion

The current study provides insight into supplement use of Greek cyclists. The consumption of carbohydrates, caffeine and energy drinks was beneficial for the cycling performance. Athletes lack knowledge about ergogenic aids, as they are often consulted by their coaches who had limited nutrition and ergogenic aids information. The presence of certified sports dietitians is vital in order to maximize athletes' records and protect them from receiving useless aids.

Further research is needed to evaluate supplement use of athletes, in combination with their nutrition status and Mediterranean diet adherence in larger groups of athletes. Variables, like duration of supplementation, quantity and type of supplements should be considered in future studies as they might have beneficial or adverse effects on cyclists' performance. Given the widespread use of supplements, dietitians and physicians have to collaborate in order to counsel cyclists about supplements' effectiveness, safety and legality.

6. Limitations

The results regarding the impact of ergogenic aids such as caffeine, carbohydrates and energy drinks on cycling performance should be presented with reservation, as the sample was small and we did not take into account the quantity, frequency and combined use of ergogenic supplements received by each athlete.

References

1 

Abian P., Del Coso J., Salinero J. J., Gallo-Salazar C., Areces F., Ruiz-Vicente D., Lara B., Soriano L., Muñoz V., Abian-Vicen J., The ingestion of a caffeinated energy drink improves jump performance and activity patterns in elite badminton players, Journal of Sports Sciences, Year: 2015, Volume: 33, Issue: 10, Page: 1042-1050. DOI: 10.1080/02640414.2014.981849

2 

Anastasiou C. A., Kavouras S. A., Koutsari C., Georgakakis C., Skenderi K., Beer M., Sidossis L. S., Effect of maltose-containing sports drinks on exercise performance, International Journal of Sport Nutrition and Exercise Metabolism, Year: 2004, Volume: 14, Issue: 6, Page: 609-625. DOI: 10.1123/ijsnem.14.6.609

3 

Arrese A. L., Ostáriz E. S., Skinfold thicknesses associated with distance running performance in highly trained runners, Journal of Sports Sciences, Year: 2006, Volume: 24, Issue: 1, Page: 69-76. DOI: 10.1080/02640410500127751

4 

Barrero A., Erola P., Bescós R., Energy balance of triathletes during an ultra-endurance event, Nutrients, Year: 2015, Volume: 7, Issue: 1, Page: 209-222. DOI: 10.3390/nu7010209

5 

Beattie K., Carson BP., Lyons M., Kenny IC., The Effect of Maximal- Explosive-Strength Training on Performance Indicators in Cyclists, Int J Sports Physiol Perform, Year: 2016, Page: 25

6 

Beaumont R., Cordery P., Funnell M., Mears S., James L., Watson P., Chronic ingestion of a low dose of caffeine induces tolerance to the performance benefits of caffeine, Journal of Sports Sciences, Year: 2016, Page: 1-8. DOI: 10.1080/02640414.2016.1241421

7 

Black C. D., Waddell D. E., Gonglach A. R., Caffeine's ergogenic effects on cycling: Neuromuscular and perceptual factors, Medicine & Science in Sports & Exercise, Year: 2015, Volume: 47, Issue: 6, Page: 1145-1158. DOI: 10.1249/MSS.0000000000000513

8 

Bortolotti H., Altimari L. R., Vitor-Costa M., Cyrino E. S., Performance during a 20-km cycling time-trial after caffeine ingestion, Journal of the International Society of Sports Nutrition, Year: 2014, Volume: 11, Issue: 1, article no. 45, DOI: 10.1186/s12970-014-0045-8

9 

Braun H., Koehler K., Geyer H., Kleinert J., Mester J., Schänzer W., Dietary supplement use among elite young German athletes, International Journal of Sport Nutrition and Exercise Metabolism, Year: 2009, Volume: 19, Issue: 1, Page: 97-109. DOI: 10.1123/ijsnem.19.1.97

10 

Broad E. M., Maughan R. J., Galloway S. D. R., Effects of four weeks L-Carnitine L-tartrate ingestion on substrate utilization during prolonged exercise, International Journal of Sport Nutrition and Exercise Metabolism, Year: 2005, Volume: 15, Issue: 6, Page: 665-679. DOI: 10.1123/ijsnem.15.6.665

11 

Brooks J. H., Wyld K., Caffeine Supplementation as an Ergogenic Aid for Muscular Strength and Endurance: A Recommendation for Coaches and Athletes, Journal of Athletic Enhancement, Year: 2016, Volume: 5, Issue: 4, DOI: 10.4172/2324-9080.1000235

12 

Bruunsgaard H., Physical activity and modulation of systemic low-level inflammation, Journal of Leukocyte Biology, Year: 2005, Volume: 78, Issue: 4, Page: 819-835. DOI: 10.1189/jlb.0505247

13 

Burke L. M., Hawley J. A., Wong S. H. S., Jeukendrup A. E., Carbohydrates for training and competition, Journal of Sports Sciences, Year: 2011, Volume: 29, Issue: 1, Page: S17-S27. DOI: 10.1080/02640414.2011.585473

14 

Burke L. M., Millet G., Tarnopolsky M. A., Nutrition for distance events, Journal of Sports Sciences, Year: 2007, Volume: 25, Issue: 1, Page: 29-38. DOI: 10.1080/02640410701607239

15 

Calfee R., Fadale P., Popular ergogenic drugs and supplements in young athletes, Pediatrics, Year: 2006, Volume: 117, Issue: 3, Page: e577-e589. DOI: 10.1542/peds.2005-1429

16 

Chlíbková D., Knechtle B., Rosemann T., Tomášková I., Chadim V., Shortall M., Nutrition habits in 24-hour mountain bike racers, SpringerPlus, Year: 2014, Volume: 3, Issue: 1, article no. 715, Page: 1-11. DOI: 10.1186/2193-1801-3-715

17 

Clauson K. A., Shields K. M., McQueen C. E., Persad N., Safety issues associated with commercially available energy drinks, Journal of the American Pharmacist Association, Year: 2008, Volume: 48, Issue: 3, Page: e55-e63. DOI: 10.1331/JAPhA.2008.07055

18 

Close G. L., Hamilton D. L., Philp A., Burke L. M., Morton J. P., New strategies in sport nutrition to increase exercise performance, Free Radical Biology & Medicine, Year: 2016, Volume: 98, Page: 144-158. DOI: 10.1016/j.freeradbiomed.2016.01.016

19 

. P. C., . C. M., . C. W., . W. O., Nutritional intake during a 244 km multisport ultraendurance race, Pakistan Journal of Nutrition, Year: 2002, Volume: 1, Issue: 3, Page: 124-126. DOI: 10.3923/pjn.2002.124.126

20 

Correia-Oliveira C. R., Bertuzzi R., Dal'Molin Kiss M. A. P., Lima-Silva A. E., Strategies of dietary carbohydrate manipulation and their effects on performance in cycling time trials, Sports Medicine, Year: 2013, Volume: 43, Issue: 8, Page: 707-719. DOI: 10.1007/s40279-013-0054-9

21 

Dascombe B. J., Karunaratna M., Cartoon J., Fergie B., Goodman C., Nutritional supplementation habits and perceptions of elite athletes within a state-based sporting institute, Journal of Science and Medicine in Sport, Year: 2010, Volume: 13, Issue: 2, Page: 274-280. DOI: 10.1016/j.jsams.2009.03.005

22 

Diehl K., Thiel A., Zipfel S., Mayer J., Schnell A., Schneider S., Elite adolescent athletes' use of dietary supplements: Characteristics, opinions, and sources of supply and information, International Journal of Sport Nutrition and Exercise Metabolism, Year: 2012, Volume: 22, Issue: 3, Page: 165-174. DOI: 10.1123/ijsnem.22.3.165

23 

Erdman K. A., Fung T. S., Doyle-Baker P. K., Verhoef M. J., Reimer R. A., Dietary supplementation of high-performance Canadian athletes by age and gender, Clinical Journal of Sport Medicine, Year: 2007, Volume: 17, Issue: 6, Page: 458-464. DOI: 10.1097/JSM.0b013e31815aed33

24 

Eudy A. E., Gordon L. L., Hockaday B. C., Lee D. A., Lee V., Luu D., Martinez C. A., Ambrose P. J., Efficacy and safety of ingredients found in preworkout supplements, American Journal of Health-System Pharmacy, Year: 2013, Volume: 70, Issue: 7, Page: 577-588. DOI: 10.2146/ajhp120118

25 

Foddy B., Savulescu J., Ethics of Performance Enhancement in Sport: Drugs and Gene Doping, Principles of Health Care Ethics: Second Edition, Year: 2007, Page: 511-519. DOI: 10.1002/9780470510544.ch70

26 

Ganio M. S., Klau J. F., Casa D. J., Armstrong L. E., Maresh C. M., Effect of caffeine on sport-specific endurance performance: a systematic review, The Journal of Strength and Conditioning Research, Year: 2009, Volume: 23, Issue: 1, Page: 315-324. DOI: 10.1519/jsc.0b013e31818b979a

27 

Geesmann B., Mester J., Koehler K., Energy balance, macronutrient intake, and hydration status during a 1,230 km ultra-endurance bike marathon, International Journal of Sport Nutrition and Exercise Metabolism, Year: 2014, Volume: 24, Issue: 5, Page: 497-506. DOI: 10.1123/ijsnem.2013-0169

28 

Geyer H., Parr M. K., Koehler K., Mareck U., Schänzer W., Thevis M., Nutritional supplements cross-contaminated and faked with doping substances, Journal of Mass Spectrometry, Year: 2008, Volume: 43, Issue: 7, Page: 892-902. DOI: 10.1002/jms.1452

29 

Glaister M., Pattison J. R., Muniz-Pumares D., Patterson S. D., Foley P., Effects of dietary nitrate, caffeine, and their combination on 20-km cycling time trial performance, The Journal of Strength and Conditioning Research, Year: 2015, Volume: 29, Issue: 1, Page: 165-174. DOI: 10.1519/JSC.0000000000000596

30 

Graham-Paulson T., Perret C., Goosey-Tolfrey V., Improvements in cycling but not handcycling 10 km time trial performance in habitual caffeine users, Nutrients, Year: 2016, Volume: 8, Issue: 7, article no. 393, DOI: 10.3390/nu8070393

31 

Hassapidou M. N., Manstrantoni A., Dietary intakes of elite female athletes in Greece, Journal of Human Nutrition and Dietetics, Year: 2001, Volume: 14, Issue: 5, Page: 391-396. DOI: 10.1046/j.1365-277X.2001.00307.x

32 

Hassapidou M. N., Fourtounopoulos D., Efstratiou E., Kitsou S., Papakitsos C., Dietary intakes of Greek basketball players, Nutrition & Food Science, Year: 2003, Volume: 33, Issue: 1, Page: 23-27. DOI: 10.1108/00346650310459536

33 

Henning A. D., Dimeo P., The complexities of anti-doping violations: A case study of sanctioned cases in all performance levels of USA cycling, Performance Enhancement and Health, Year: 2015, DOI: 10.1016/j.peh.2015.08.001

34 

Higgins S., Straight C. R., Lewis R. D., The effects of preexercise caffeinated coffee ingestion on endurance performance: An evidence-based review, International Journal of Sport Nutrition and Exercise Metabolism, Year: 2016, Volume: 26, Issue: 3, Page: 221-239. DOI: 10.1123/ijsnem.2015-0147

35 

Hodgson A. B., Randell R. K., Jeukendrup A. E., The metabolic and performance effects of caffeine compared to coffee during endurance exercise, PLoS ONE, Year: 2013, Volume: 8, Issue: 4, DOI: 10.1371/journal.pone.0059561

36 

Huang S.-H., Johnson K., Pipe A. L., The use of dietary supplements and medications by Canadian athletes at the Atlanta and Sydney olympic games, Clinical Journal of Sport Medicine, Year: 2006, Volume: 16, Issue: 1, Page: 27-33. DOI: 10.1097/01.jsm.0000194766.35443.9c

37 

Ivy J. L., Kammer L., Ding Z., Wang B., Bernard J. R., Liao Y.-H., Hwang J., Improved cycling time-trial performance after ingestion of a caffeine energy drink, International Journal of Sport Nutrition and Exercise Metabolism, Year: 2009, Volume: 19, Issue: 1, Page: 61-78. DOI: 10.1123/ijsnem.19.1.61

38 

Jeukendrup A. E., Hopkins S., Aragón-Vargas L. F., Hulston C., No effect of carbohydrate feeding on 16 km cycling time trial performance, European Journal of Applied Physiology, Year: 2008, Volume: 104, Issue: 5, Page: 831-837. DOI: 10.1007/s00421-008-0838-z

39 

Khanna G. L., Manna I., Supplementary effect of carbohydrate-electrolyte drink on sports performance, lactate removal & cardiovascular response of athletes, Indian Journal of Medical Research, Year: 2005, Volume: 121, Issue: 5, Page: 665-669.

40 

Khodaee M., Olewinski L., Shadgan B., Kiningham R. R., Rapid weight loss in sports with weight classes, Current Sports Medicine Reports, Year: 2015, Volume: 14, Issue: 6, Page: 435-441. DOI: 10.1249/JSR.0000000000000206

41 

Kimber N. E., Ross J. J., Mason S. L., Speedy D. B., Energy Balance during an Ironman Triathlon in Male and Female Triathletes, International Journal of Sport Nutrition and Exercise Metabolism, Year: 2002, Volume: 12, Issue: 1, Page: 47-62. DOI: 10.1123/ijsnem.12.1.47

42 

Knechtle B., Wirth A., Rüst C. A., Rosemann T., The relationship between anthropometry and split performance in recreational male ironman triathletes, Asian Journal of Sports Medicine, Year: 2011, Volume: 2, Issue: 1, Page: 23-30.

43 

Knechtle B., Zingg M., Stiefel M., Rosemann T., Rüst C., What predicts performance in ultra-triathlon races? &ndash; a comparison between Ironman distance triathlon and ultra-triathlon, Open Access Journal of Sports Medicine, Page: 149 DOI: 10.2147/OAJSM.S79273

44 

Lane S. C., Areta J. L., Bird S. R., Coffey V. G., Burke L. M., Desbrow B., Karagounis L. G., Hawley J. A., Caffeine ingestion and cycling power output in a low or normal muscle glycogen state, Medicine & Science in Sports & Exercise, Year: 2013, Volume: 45, Issue: 8, Page: 1577-1584. DOI: 10.1249/mss.0b013e31828af183

45 

Lee M. J. C., Hammond K. M., Vasdev A., Poole K. L., Impey S. G., Close G. L., Morton J. P., Self-selecting fluid intake while maintaining high carbohydrate availability does not impair half-marathon performance, International Journal of Sports Medicine, Year: 2014, Volume: 35, Issue: 14, Page: 1216-1222. DOI: 10.1055/s-0034-1375635

46 

Little J. P., Chilibeck P. D., Ciona D., Forbes S., Rees H., Vandenberg A., Zello G. A., Effect of low- and high-glycemic-index meals on metabolism and performance during high-intensity, intermittent exercise, International Journal of Sport Nutrition and Exercise Metabolism, Year: 2010, Volume: 20, Issue: 6, Page: 447-456. DOI: 10.1123/ijsnem.20.6.447

47 

Lourida I., Soni M., Thompson-Coon J., Purandare N., Lang I. A., Ukoumunne O. C., Llewellyn D. J., Mediterranean diet, cognitive function, and dementia: a systematic review, Epidemiology, Year: 2013, Volume: 24, Issue: 4, Page: 479-489. DOI: 10.1097/ede.0b013e3182944410

48 

Lystrup R. M., Leggit J. C., Caffeine toxicity due to supplement use in caffeine—naïve individual: A cautionary tale, Military Medicine, Year: 2015, Volume: 180, Issue: 8, Page: e936-e940. DOI: 10.7205/MILMED-D-15-00045

49 

Malinauskas B. M., Overton R. F., Carraway V. G., Cash B. C., Supplements of interest for sport-related injury and sources of supplement information among college athletes, Advances in Medical Sciences, Year: 2007, Volume: 52, Page: 50-54.

50 

Marcos A., Nova E., Montero A., Changes in the immune system are conditioned by nutrition, European Journal of Clinical Nutrition, Year: 2003, Volume: 57, Page: S66-S69. DOI: 10.1038/sj.ejcn.1601819

51 

Martínez-Sellés M., Datino T., Figueiras-Graillet L., Gama J. G., Jones C., Franklin R., Fernández-Avilés F., Cardiovascular safety of anagrelide in healthy subjects: Effects of caffeine and food intake on pharmacokinetics and adverse reactions, Clinical Drug Investigation, Year: 2013, Volume: 33, Issue: 1, Page: 45-54. DOI: 10.1007/s40261-012-0032-2

52 

Maughan R. J., King D. S., Lea T., Dietary supplements, Journal of Sports Sciences, Year: 2004, Volume: 22, Issue: 1, Page: 95-113. DOI: 10.1080/0264041031000140581

53 

Maughan R. J., Contamination of dietary supplements and positive drug tests in sport, Journal of Sports Sciences, Year: 2005, Volume: 23, Issue: 9, Page: 883-889. DOI: 10.1080/02640410400023258

54 

Miller B., O’Connor H., Orr R., Ruell P., Cheng H. L., Chow C. M., Combined caffeine and carbohydrate ingestion: effects on nocturnal sleep and exercise performance in athletes, European Journal of Applied Physiology, Year: 2014, Volume: 114, Issue: 12, Page: 2529-2537. DOI: 10.1007/s00421-014-2973-z

55 

Nicolò A., Bazzucchi I., Felici F., Patrizio F., Sacchetti M., Mechanical and electromyographic responses during the 3-min all-out test in competitive cyclists, Journal of Electromyography & Kinesiology, Year: 2015, Volume: 25, Issue: 6, Page: 907-913. DOI: 10.1016/j.jelekin.2015.08.006

56 

Nieper A., Nutritional supplement practices in UK junior national track and field athletes, British Journal of Sports Medicine, Year: 2005, Volume: 39, Issue: 9, Page: 645-649. DOI: 10.1136/bjsm.2004.015842

57 

Nikolopoulos D. D., Spiliopoulou C., Theocharis S. E., Doping and musculoskeletal system: Short-term and long-lasting effects of doping agents, Fundamental & Clinical Pharmacology, Year: 2011, Volume: 25, Issue: 5, Page: 535-563. DOI: 10.1111/j.1472-8206.2010.00881.x

58 

O'Neal E. K., Wingo J. E., Richardson M. T., Leeper J. D., Neggers Y. H., Bishop P. A., Half-marathon and full-marathon runners' hydration practices and perceptions, Journal of Athletic Training, Year: 2011, Volume: 46, Issue: 6, Page: 581-591. DOI: 10.4085/1062-6050-46.6.581

59 

Ormsbee M. J., Bach C. W., Baur D. A., Pre-exercise nutrition: the role of macronutrients, modified starches and supplements on metabolism and endurance performance, Nutrients, Year: 2014, Volume: 6, Issue: 5, Page: 1782-1808. DOI: 10.3390/nu6051782

60 

Panagiotakos D. B., Pitsavos C., Stefanadis C., Dietary patterns: a Mediterranean diet score and its relation to clinical and biological markers of cardiovascular disease risk, Nutrition, Metabolism & Cardiovascular Diseases, Year: 2006, Volume: 16, Issue: 8, Page: 559-568. DOI: 10.1016/j.numecd.2005.08.006

61 

Papandreou D., Eystathiadis P., Bouzoukiu V., Hassapidou M., Tsitskaris G., Garefis A., Dietary assessment, anthropometric measurements and nutritional status of Greek professional athletes, Nutrition & Food Science, Year: 2007, Volume: 37, Issue: 5, Page: 338-344. DOI: 10.1108/00346650710828361

62 

Papadopoulou SK., Food Choice criteria of adolescents. The role of physical activity and anthropometric, dietetic and psychological factors [Dissertation, thesis], Year: 2001, GreeceUnpublished Dissertation, Aristotle University of Thessaloniki

63 

Papadopoulou S. K., Gouvianaki A., Grammatikopoulou M. G., Maraki Z., Pagkalos I. G., Malliaropoulos N., Hassapidou M. N., Maffulli N., Body Composition and Dietary Intake of Elite Cross-country Skiers Members of the Greek National Team, Asian Journal of Sports Medicine, Year: 2012, Volume: 3, Issue: 4, DOI: 10.5812/asjsm.34548

64 

Papadopoulou S. K., Papadopoulou S. D., Nutritional status of top team-sport athletes according to body fat, Nutrition & Food Science, Year: 2010, Volume: 40, Issue: 1, Page: 64-73. DOI: 10.1108/00346651011015935

65 

Papadopoulou SD., Papadopoulou SK., Zaggelidis G., Konstantinidou X., Tsitskaris G., Maraki Z., Dietary and health related habits of Greek elite female team sport athletes. Stiinta Sportului, Sports Science magazine, Maraki Z. Dietary and health related habits of Greek elite female team sport athletes. Stiinta Sportului, Year: 2009, Volume: 1, 179-91 Page: 79-91.

66 

Papadopoulou SK., Papadopoulou SD., Skoufas D., Yiannakos A., Natsis K., Dietary intake differences between volleyball and handball women athletes of the Olympic national team. Medicina Sportiva, Natsis K. Dietary intake differences between volleyball and handball women athletes of the Olympic national team. Medicina Sportiva, Year: 2008, Volume: 16, 16983-989 Page: 983-989.

67 

Papadopoulou S. K., Papadopoulou S. D., Gallos G. K., Macro- and micro-nutrient intake of adolescent Greek female volleyball players, Journal of the International Society of Sports Nutrition, Year: 2002, Volume: 12, Issue: 1, Page: 73-80.

68 

Paton C., Costa V., Guglielmo L., Effects of caffeine chewing gum on race performance and physiology in male and female cyclists, Journal of Sports Sciences, Year: 2015, Volume: 33, Issue: 10, Page: 1076-1083. DOI: 10.1080/02640414.2014.984752

69 

Petróczi A., Naughton D. P., Pearce G., Bailey R., Bloodworth A., McNamee M., Nutritional supplement use by elite young UK athletes: Fallacies of advice regarding efficacy, Journal of the International Society of Sports Nutrition, Year: 2008, Volume: 5, article no. 22, DOI: 10.1186/1550-2783-5-22

70 

Pettitt R. W., Niemeyer J. D., Sexton P. J., Lipetzky A., Murray S. R., Do the noncaffeine ingredients of energy drinks affect metabolic responses to heavy exercise?, The Journal of Strength and Conditioning Research, Year: 2013, Volume: 27, Issue: 7, Page: 1994-1999. DOI: 10.1519/JSC.0b013e3182736e31

71 

Porrini M., Del Bo C., Ergogenic Aids and Supplements, Frontiers of Hormone Research, Year: 2016, Volume: 47, Page: 128-152. DOI: 10.1159/000445176

72 

Pöchmüller M., Schwingshackl L., Colombani P. C., Hoffmann G., A systematic review and meta-analysis of carbohydrate benefits associated with randomized controlled competition-based performance trials, Journal of the International Society of Sports Nutrition, Year: 2016, Volume: 13, Issue: 1, article no. 27, DOI: 10.1186/s12970-016-0139-6

73 

Quiterio A. L., Carnero E. A., Silva A. M., Baptista F., Sardinha L. B., Weekly training hours are associated with molecular and cellular body composition levels in adolescent athletes, The Journal of Sports Medicine and Physical Fitness , Year: 2009, Volume: 49, Issue: 1, Page: 54-63.

74 

Rodriguez N. R., DiMarco N. M., Langley S., Position of the American dietetic association, dietitians of Canada, and the american college of sports medicine: nutrition and athletic performance, Journal of the Academy of Nutrition and Dietetics, Year: 2009, Volume: 109, Issue: 3, Page: 509-527. DOI: 10.1016/j.jada.2009.01.005

75 

Salas-Salvadó J., Guasch-Ferré M., Lee C.-H., Estruch R., Clish C. B., Ros E., Protective effects of the mediterranean diet on type 2 diabetes and metabolic syndrome, Journal of Nutrition, Year: 2016, Volume: 146, Issue: 4, Page: 920-927. DOI: 10.3945/jn.115.218487

76 

Sánchez-Benito J. L., Sánchez-Soriano E., Ginart Suárez J., Assessment of the Mediterranean Diet Adequacy Index of a collective of young cyclists, Nutrición Hospitalaria, Year: 2009, Volume: 24, Issue: 1, Page: 77-86.

77 

Sánchez-Muñoz C., Zabala M., Muros J. J., Nutritional intake and anthropometric changes of professional road cyclists during a 4-day competition, Scandinavian Journal of Medicine & Science in Sports, Year: 2016, Volume: 26, Issue: 7, Page: 802-808. DOI: 10.1111/sms.12513

78 

Shearer J., Graham T. E., Performance effects and metabolic consequences of caffeine and caffeinated energy drink consumption on glucose disposal, Nutrition Reviews, Year: 2014, Volume: 72, supplement 1 Page: 121-136. DOI: 10.1111/nure.12124

79 

Tike P. S., Soto G. R., Valenzuela T. H., Agüero S. D., Sepúlveda R. Y., Body composition parameters and relationship with the maximal aerobic power in recreational cyclists, Nutrición Hospitalaria, Year: 2015, Volume: 32, Issue: 5, Page: 2223-2227. DOI: 10.3305/nh.2015.32.5.9656

80 

Sofi F., Abbate R., Gensini G. F., Casini A., Accruing evidence on benefits of adherence to the Mediterranean diet on health: an updated systematic review and meta-analysis, American Journal of Clinical Nutrition, Year: 2010, Volume: 92, Issue: 5, Page: 1189-1196. DOI: 10.3945/ajcn.2010.29673

81 

Spence A. L., Sim M., Landers G., Peeling P., A comparison of caffeine versus pseudoephedrine on cycling time-trial performance, International Journal of Sport Nutrition and Exercise Metabolism, Year: 2013, Volume: 23, Issue: 5, Page: 507-512. DOI: 10.1123/ijsnem.23.5.507

82 

Stellingwerff T., Maughan R. J., Burke L. M., Nutrition for power sports: Middle-distance running, track cycling, rowing, canoeing/kayaking, and swimming, Journal of Sports Sciences, Year: 2011, Volume: 29, Issue: 1, Page: S79-S89. DOI: 10.1080/02640414.2011.589469

83 

Suzic Lazic J., Dikic N., Radivojevic N., Mazic S., Radovanovic D., Mitrovic N., Lazic M., Zivanic S., Suzic S., Dietary supplements and medications in elite sport - polypharmacy or real need?, Scandinavian Journal of Medicine & Science in Sports, Year: 2011, Volume: 21, Issue: 2, Page: 260-267. DOI: 10.1111/j.1600-0838.2009.01026.x

84 

Talanian J. L., Spriet L. L., Low and moderate doses of caffeine late in exercise improve performance in trained cyclists, Applied Physiology, Nutrition, and Metabolism, Year: 2016, Volume: 41, Issue: 8, Page: 850-855. DOI: 10.1139/apnm-2016-0053

85 

Knechtle B., Tanda G., Effects of training and anthropometric factors on marathon and 100 km ultramarathon race performance, Open Access Journal of Sports Medicine, Page: 129 DOI: 10.2147/OAJSM.S80637

86 

Thomas D. T., Erdman K. A., Burke L. M., Position of the academy of nutrition and dietetics, dietitians of Canada, and the American college of sports medicine: nutrition and athletic performance, Journal of the Academy of Nutrition and Dietetics, Year: 2016, Volume: 116, Issue: 3, Page: 501-528. DOI: 10.1016/j.jand.2015.12.006

87 

Wardenaar F. C., Ceelen I. J., Van Dijk J., Hangelbroek R. W., Van Roy L., Van der Pouw B., De Vries J. H., Mensink M., Witkamp R. F., Nutritional Supplement Use by Dutch Elite and Sub-Elite Athletes: Does Receiving Dietary Counseling Make a Difference?, International Journal of Sport Nutrition and Exercise Metabolism, Year: 2017, Volume: 27, Issue: 1, Page: 32-42. DOI: 10.1123/ijsnem.2016-0157

88 

Winger J. M., Dugas J. P., Dugas L. R., Beliefs about hydration and physiology drive drinking behaviours in runners, British Journal of Sports Medicine, Year: 2011, Volume: 45, Issue: 8, Page: 646-649. DOI: 10.1136/bjsm.2010.075275

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