A study of female cyclists in Spain found that a large majority used sports supplements more as a way to improve their overall health rather than their cycling performance.

The study, published in the journal Nutrients, supports the widely held hypothesis that there is more use of supplements among athletes that train at high levels or compete. The 316 women cyclists participated in several competitive categories and a cyclotourist category. Of the study participants, 85% were taking supplements.

Where supplements are purchased matters, the study found, with a warning that buying from the Internet could have serious implications. Also, relying on expert advice regarding supplements is more likely to keep cyclists from inadvertent doping, the research said.

The findings were in line with previous research. “Specifically, performance and health emerged as the most common reasons for (supplement) use, consistent with findings reported in (earlier literature),” the study said.

Nutritional deficiency was the third most-mentioned reason for taking supplements in the recent study. “These results are similar to those of a study conducted with elite under-23 male cyclists, where 49.1% cited ‘addressing a dietary deficiency’ as their main reason” for supplementation, the study noted.

“However, the results differ from findings in various studies on other endurance sports involving participants of similar ages (between 34.8 and 43.1 years), where athletic performance was the most frequently chosen reason,” the study said.

Sex, competition and supplements

Sex and competitive level are two variables that most influence supplement consumption, according to the research. While the results support the notion that there is higher consumption of supplements at high levels of training and competition, they contradict the hypothesis that women consume fewer supplements than men at a similar level of competition.

Sport bars (77.5%) and gels (61.4%) were the most consumed supplements by the study participants. This is consistent with results from similar research on endurance athletes, where sports drinks, energy bars, and sports gels were identified as the three most commonly consumed supplements, the study found. 

Sourcing matters

The study said the location where supplements were purchased is important in ensuring appropriate use and access to higher-quality products. The primary source of supplements was found to be pharmacies (60.8%) and specialized stores (59.2%).

The Internet, chosen by 44.9% of participants, is frequently cited as a preferred venue for purchasing supplements, which could cause concerns, the research noted. “This trend suggests that a significant proportion of female cyclists might be at risk of inadvertent doping due to their (supplement purchasing practices,” according to the study.

“The lack of strict international regulations on dietary supplements, coupled with risks of contamination and insufficient guidance on correct usage and scientific backing, heightens the probability of improper or excessive supplement intake and inadvertent doping, especially in the largely unregulated online marketplace,” the study said.

Who’s giving advice?

The main sources of advice for the cyclists came from dietitian-nutritionists (58.9%), medical doctors (44.6%) and fitness coaches (36.4%). 

The role of dietitian-nutritionists is gaining significance, as recent research on supplement consumption highlights them as either the primary or secondary source of advice for athletes, the study noted. “Athletes who receive information from a dietitian-nutritionist as their primary source of nutritional advice have better eating habits, a better understanding of nutrient timing, and a stronger scientific basis for (supplementation) selection.”

The cyclotourist group was found to be the least likely to seek advice from dietitian-nutritionists (25.0%), and medical doctors (17.8%). This highlights the importance of relying on credible sources for guidance, as inadequate or incorrect advice can result in the use of supplements lacking scientific support or, more critically, lead to unintentional doping and health risks, the study said. This group also consumed the fewest number of supplements.

Most popular choices

Among the most used were caffeine supplements, which have been shown to improve various performance metrics, including velocity and power during strength training, muscular endurance and performance in sprint and agility tests.

Interestingly, several scientifically validated supplements were not among the top 20 most used by the participant, the study said. These include beta-alanine, sodium bicarbonate, creatine, dietary nitrate/beetroot juice and glycerol.

Iron was one of the 10 most-consumed supplements by the cyclists. Iron-deficiency anemia and iron deficiency are five to seven times more common in women than men, according to the study. “These prevalence rates are related to sex differences, poor dietary intake, exercise-induced iron losses, and disruptions in iron regulation during the menstrual cycle. This is an important finding, as iron presents itself as an effective supplement for female athletes,” the research said.

The study concluded that although supplements should be a complementary part of an athlete’s proper planning, which includes factors such as genetics, training, and diet, there tends to be an excessive emphasis on their consumption.

“Despite the widespread and standardized use of (supplements), it is crucial for both health professionals and athletes to conduct a cost–benefit analysis before their use, considering their safety, efficacy, and legality. Moreover, the consumption of supplements should complement sports planning and should not replace an adequate diet or proper food choices,” the study advised.