Nutrition and hydration for cyclists: optimal strategies to improve performance

Nutrition and hydration for cyclists: optimal strategies to improve performance

JIANDA LI1, QIAN LIU2, JINGPENG WANG3, QIAN CHENG4

1Shandong Shooting and Bicycle Campaign Management Center, Jinan, People’s Republic of China; 2Jining Sports Training Center, Jining, People’s Republic of China; 3Heze Sports Sports School, Heze, People’s Republic of China; 4Rizhao Sports Sports School, Rizhao, People’s Republic of China.

Summary. Background: Proper nutrition and hydration are key to athletic performance. This study evaluated the effects of a balanced diet and regulated hydration on professional cyclists’ physical endurance. Methods. Eighty cyclists aged 20-35 were divided into experimental (n=40) and control (n=40) groups. The experimental group followed a structured diet (53% complex carbohydrates, 27% plant-based fats, 20% quality proteins), supplemented with whey protein and electrolytes, and consumed isotonic drinks. The control group maintained a typical diet high in simple carbohydrates with irregular hydration. Performance was monitored over eight weeks. Results. The experimental group showed a 12% increase in speed, 18% improvement in endurance, and stable electrolyte levels. The control group saw only modest gains and signs of dehydration. Complex carbohydrates, protein intake, and isotonic drinks positively correlated with improved energy balance. Conclusions. A structured diet and adequate hydration reduce physiological stress and improve endurance and recovery in cyclists, supporting their integration into endurance training regimens.

Key words. Diet, electrolytes, energy.

Nutrizione e idratazione per i ciclisti: strategie ottimali per migliorare la performance

Riassunto. Background. Una corretta alimentazione e un’adeguata idratazione sono elementi fondamentali per la performance atletica. Questo studio ha valutato gli effetti di una dieta bilanciata e di una regolazione mirata dell’idratazione sulla resistenza fisica di ciclisti professionisti. Metodi. Ottanta ciclisti di età compresa tra 20 e 35 anni sono stati suddivisi in un gruppo sperimentale (n=40) e in un gruppo di controllo (n=40). Il gruppo sperimentale ha seguito una dieta strutturata (53% carboidrati complessi, 27% grassi di origine vegetale, 20% proteine di alta qualità), integrata con proteine del siero del latte ed elettroliti, e ha consumato bevande isotoniche. Il gruppo di controllo ha mantenuto una dieta tipica ricca di carboidrati semplici con idratazione irregolare. Le performance sono state monitorate per otto settimane. Risultati. Il gruppo sperimentale ha mostrato un incremento del 12% nella velocità, un miglioramento del 18% nella resistenza e livelli elettrolitici stabili. Il gruppo di controllo ha registrato solo modesti miglioramenti e segni di disidratazione. L’assunzione di carboidrati complessi, proteine e bevande isotoniche è risultata positivamente correlata a un migliore equilibrio energetico. Conclusioni. Una dieta strutturata e un’idratazione adeguata riducono lo stress fisiologico e migliorano la resistenza e il recupero nei ciclisti, sostenendone l’integrazione nei programmi di allenamento di endurance.

Parole chiave. Dieta, elettroliti, energia.

Introduction

Optimising nutrition and hydration are a crucial factor in enhancing the physical endurance and performance of cyclists. Cycling, which demands prolonged physical exertion, places significant strain on maintaining the water-salt balance, ensuring rapid recovery, and supplying the body with adequate energy. Poor nutrition, irregular hydration, and the absence of a systematic approach to dietary planning can result in exhaustion, dehydration, and diminished athletic performance. Understanding effective nutrition and hydration strategies is essential for achieving peak performance.

The role of carbohydrates in meeting the energy demands of cyclists has been extensively studied by Tan et al.1, who demonstrated that a diet enriched with complex carbohydrates increases the duration of training to fatigue by 15%. Their study highlights that regular consumption of complex carbohydrates ensures stable replenishment of muscle glycogen stores, thereby reducing the risk of physical exhaustion during competition. Conversely, the authors observed that an insufficient intake of carbohydrates can lead to rapid energy depletion, negatively impacting athletes’ endurance and performance.

Hydration, as a critical aspect of maintaining physical activity, was analysed by Xu et al.2, who examined the effects of isotonic drink consumption on thermoregulation and blood plasma osmolarity during intense training. Their findings revealed that isotonic drinks enriched with electrolytes can reduce the risk of dehydration by 30% and support more effective regulation of the body’s temperature balance. The authors also highlighted that failure to adhere to a proper hydration regimen can lead to heat stress and significantly impair physical endurance.

Wei et al.³ studied the optimal macronutrient balance for athletes, showing that a diet with 50-55% carbohydrates, 20-25% proteins, and 20-25% fats help cyclists recover energy efficiently. However, the study did not consider training duration as a variable in macronutrient planning. Muros et al.⁴ found that whey protein supplements reduce muscle damage markers like creatine phosphokinase and promote muscle protein synthesis. Still, the study did not assess the added benefits of combining proteins with carbohydrates.

Valiño-Marques et al.⁵ reported that losing over 2% of body weight through sweat reduces cyclists’ endurance by 15%, highlighting the need for fluid intake during training. Yet, the study did not compare the effectiveness of different drink types. Kurtz et al.⁶ showed that isotonic drinks with sodium, potassium, and magnesium help maintain physiological stability and water-salt balance in cyclists. Their study, however, did not explore long-term health effects. Pellicer-Caller et al.⁷ demonstrated that vegetable fats support sustained energy during prolonged training, especially when combined with complex carbohydrates.

The integration of various nutritional components into training programmes was examined by Lisk et al.8, who investigated the combined effect of complex carbohydrates, proteins, and isotonic drinks on the physical performance of cyclists. The authors found that this combination reduces physiological stress, sustains high levels of endurance, and enhances overall performance. However, their study focused on short-term training cycles and did not consider the long-term effects of such a strategy.

The aim of the present study was to evaluate the impact of a balanced diet and optimal hydration on the endurance, performance, and recovery of cyclists, with particular attention to the ratio of macro- and micronutrients. The objectives included analysing the optimal dietary composition, assessing the effects of isotonic drinks on physiological indicators, investigating the impact of macronutrient combinations on recovery speed, and developing recommendations for integrating a balanced diet and hydration into the training programmes of cyclists.

Materials and methods

The study was designed as a randomized controlled trial conducted over a three-month period, from January to March 2024, at Guangzhou Sport University, China. A total of 80 professional cyclists aged 20 to 35 years (48 males and 32 females) were recruited and randomly assigned to two groups: an experimental group (n=40) and a control group (n=40). Randomization was performed using a computer-generated random sequence, and stratification was applied by sex and training level to ensure balanced distribution of participant characteristics across groups. This stratified randomization was intended to control for potential confounding variables related to gender differences in metabolism and baseline endurance capacity. All cyclists provided written informed consent prior to their inclusion in the study.

Prior to the experiment, each participant completed a questionnaire to assess their baseline dietary habits, hydration practices, and physical activity levels. The questionnaire included the following questions: “How much water do you consume daily (in litres)?”, “Do you use sports drinks? If so, which ones?”, “How many times a day do you eat?”, “What foods are most often included in your diet?”, “Do you take supplements (proteins, amino acids, electrolytes)?”, “Do you feel thirsty during training?”, “How long do your training sessions usually last?”.

The nutrition and hydration strategy for the experimental group was based on a carefully developed diet consisting of three main meals and two snacks. Designed with input from nutritionists, the diet focused on a balanced macronutrient composition: 50-55% carbohydrates (emphasising complex carbohydrates such as whole grains, vegetables, and fruits), 25-30% fats (primarily from plant-based sources such as olive oil, nuts, and avocados), and 15-20% proteins (mainly from lean meat, fish, eggs, and dairy products). Additionally, participants in the experimental group received nutritional supplements, including whey protein (Optimum Nutrition Gold Standard Whey, USA) and electrolyte complexes (Nuun Hydration, USA).

Hydration in the experimental group was managed by consuming isotonic drinks (Gatorade, USA) during training and throughout the day. The recommended fluid intake was calculated individually for each cyclist, based on water losses measured by weighing participants before and after training sessions. Cyclists in the experimental group consumed 200-250 ml of isotonic drink every 20 minutes during training, in addition to drinking water before and after physical exertion. All study participants followed the assigned dietary and hydration protocols, and no dropouts occurred during the intervention period.

In contrast, the control group continued to follow their usual diet and hydration practices without external intervention. Participants in this group-maintained food diaries to document the calorie content and composition of their diet. Analysis of these diaries revealed that their typical diet was characterised by a high intake of simple carbohydrates (such as white bread and sweets), a low protein content, and irregular fluid consumption during training.

The main phase of the study lasted eight weeks, during which weekly physical endurance tests were conducted using a Wattbike Pro cycle ergometer (Wattbike, UK). All training sessions and competitions were recorded using Garmin Forerunner 945 wearable devices (Garmin Ltd., USA), which provided data on heart rate (HR), distance, average speed, and calories burned. Weekly analyses of electrolyte levels (sodium, potassium, magnesium) and dehydration markers (urine osmolarity) were conducted in the laboratory of the Sports Institute. These measurements were performed using Roche Cobas b 221 electrolyte analysers (Roche Diagnostics, Switzerland) and Atago PAL-10S refractometers (Atago Co., Japan).

To evaluate the overall physical load of the cyclists throughout the study, the Training Stress Score (TSS) indicator was used. This index is a composite measure that considers the duration of training, its intensity, and the individual physiological capabilities of the participants. Data for calculating TSS were collected using the Garmin Forerunner 945 wearable devices, which recorded real-time metrics such as HR, power, and exercise time.

where: training time – the total duration of the training session; normalised power – the average power during the training session, adjusted for intensity variations; intensity – the ratio of normalised power to Functional Threshold Power (FTP); FTP – the maximum power that a cyclist can maintain for one hour without accumulating significant fatigue.

All participants underwent a preliminary FTP test on a Wattbike Pro cycle ergometer (Wattbike, UK) to determine their FTP. FTP served as the baseline value for calculating TSS.

TSS was analysed weekly for each participant to evaluate the level of physical stress caused by training and to assess the effectiveness of the nutrition and hydration strategy.

Statistical analysis was conducted using SPSS Statistics (version 27, IBM, USA). Comparisons between groups were performed using a paired t-test, while correlation analysis was used to identify relationships between hydration levels and sports performance. All calculations were carried out with a significance level of p<0.05.

Results

The study revealed notable differences in macronutrient intake between the experimental and control groups (table 1).

The experimental group followed a tailored diet to improve endurance, consisting of 53% carbohydrates, 27% fats, and 20% proteins. Complex carbohydrates (whole grains, vegetables, fruits) ensured stable energy, while plant-based fats (nuts, avocados, seeds) provided essential fatty acids. High-quality proteins supported muscle recovery. This approach enhanced adaptation to physical stress and overall performance.

The control group exhibited significantly lower adherence to sports nutrition standards, which had a noticeable impact on their physical performance. Their diet was characterised by an excessive intake of simple carbohydrates, which accounted for 42% of total calories. This resulted in sharp fluctuations in blood glucose levels, causing energy instability during training and reducing endurance. Protein intake in the control group’s diet was only 13%, which was insufficient to support muscle mass, recovery processes, and effective anabolism following physical exertion.

In the control group, fats accounted for 34% of total calories, with a large portion being saturated. Such fats can trigger inflammation, raise cholesterol, and impair metabolic efficiency, which hindered training outcomes and reduced overall performance. Endurance tests confirmed the advantages of a balanced diet. The experimental group, following an optimal macronutrient ratio, increased average speed by 12% (from 24.3±2.1 km/h to 27.2±1.8 km/h), reflecting improved aerobic capacity. Their time to fatigue rose by 18%, due to sustained energy from complex carbs, proteins, and healthy fats.

In contrast, the control group, on an unbalanced diet, showed only a 4% speed increase and a 6% improvement in training duration. Their diet, high in simple carbs and low in quality proteins and fats, likely led to unstable blood glucose and poor endurance. Correlation analysis highlighted the role of protein and fat intake. Higher protein intake correlated with average speed (r=0.68, p<0.05), supporting muscle recovery and growth. Conversely, high simple carbohydrate intake in the control group negatively correlated with endurance (r=-0.54, p<0.05), due to glucose fluctuations and energy drops.

Moreover, vegetable fats in the experimental group enhanced fatigue resistance by providing sustained energy. Polyunsaturated fats from nuts, seeds, and avocados supported muscle metabolism and endurance.

The study also revealed significant differences in electrolyte levels and hydration markers between the experimental and control groups (table 2).

Participants in the experimental group, who adhered to the developed hydration protocol using isotonic drinks, demonstrated more stable levels of sodium, potassium, and magnesium, ensuring an optimal water-salt balance. The average sodium level in the experimental group decreased by only 2% from the initial value, indicating effective compensation for electrolyte losses during training. In contrast, the sodium level in the control group decreased by 8%, reflecting a significant loss of electrolytes due to insufficient fluid intake. These findings highlight the critical importance of a proper hydration strategy to maintain physical performance and minimise the risk of dehydration.

The experimental group recorded higher levels of potassium (4.1±0.2 mmol/l) and magnesium (0.89±0.05 mmol/l), which positively influenced the functioning of the muscular system. These levels contributed to a reduced risk of cramps during and after physical exertion – an important factor in maintaining sports performance. High magnesium levels also supported the stability of neuromuscular transmission, enabling better movement control and improving the efficiency of the body’s recovery processes following physical exercise.

Additionally, urine osmolarity, a key marker of the body’s hydration status, was significantly lower in the experimental group (732±28 mOsm/kg) compared to the control group (853±35 mOsm/kg). This result highlights the effectiveness of isotonic drinks in maintaining the water-salt balance. Adequate hydration prevented severe dehydration, which is particularly critical during intense physical exertion.

In the control group, a significant decrease in sodium and potassium levels was observed after training, indicating insufficient compensation for electrolyte losses during physical exertion. This imbalance resulted in more pronounced symptoms of muscle fatigue, reduced performance, and frequent episodes of cramping. Weight loss in this group was 2.1±0.2%, which was double the figure recorded in the experimental group (0.9±0.1%). Such a substantial loss of body weight reflects acute fluid deficiency and dehydration, which negatively impacted the body’s ability to endure prolonged physical exertion. Insufficient fluid intake and the absence of isotonic drinks in the diet of the control group participants significantly disrupted their water-salt balance, consequently reducing the duration and quality of their training.

Correlation analysis further emphasised the critical role of hydration as a determinant of performance. A strong relationship between urine osmolarity and weight loss after exercise (r=0.71, p<0.05) highlighted the necessity of maintaining optimal hydration levels. Additionally, the positive correlation between magnesium levels and recovery rate (r=0.64, p<0.05) underscored the importance of magnesium in sustaining performance and supporting recovery processes. These findings demonstrate that a balanced diet and timely compensation for electrolyte losses are essential for achieving high training efficiency and mitigating exercise-related risks.

Analysis of the physiological responses to nutrition and hydration strategies revealed a significant impact of optimal diets and hydration protocols on the functional state of professional cyclists (table 3).

Participants in the experimental group, who followed a balanced diet with an appropriate ratio of proteins, fats, and carbohydrates, and incorporated isotonic drinks to maintain water-salt balance, showed notable improvements in key physiological parameters. Specifically, they exhibited more stable osmolarity indicators, higher electrolyte levels, and reduced muscle fatigue. In contrast, the control group, who followed a conventional diet without specific adjustments, demonstrated far more modest results, highlighting the limitations of traditional approaches in achieving high physical performance.

Heart rate (HR) is a key marker of cardiovascular adaptation to physical activity and training efficiency. The experimental group demonstrated a 12 bpm reduction in HR, indicating improved cardiac function and enhanced cardiorespiratory adaptation. This reflects reduced cardiac strain and greater cardiovascular efficiency. By contrast, the control group showed only a 5 bpm decrease, suggesting limited adaptation due to unbalanced nutrition and poor hydration.

Energy metabolism optimisation in the experimental group was also evident in an 11% increase in caloric expenditure from baseline, driven by improved muscle metabolism and nutrient intake. The control group showed just a 4% rise, insufficient for sustaining high-intensity training and likely reflecting an energy deficit that impaired performance and endurance.

The experimental group showed an average speed increase of 1.3 km/h, indicating improved functional endurance. This was achieved through optimal electrolyte and energy intake via isotonic drinks and a balanced diet. In contrast, the control group showed minimal change, suggesting inadequate adaptation to physical exertion. Additionally, the experimental group had a notable reduction in training load (TSS), reflecting enhanced recovery. Regular use of isotonic drinks supported hydration and prevented fatigue accumulation, enabling consistent progress through stable water-salt and energy balance. Pronounced individual improvements were recorded in 85% of the experimental group, across cardiorespiratory function, endurance, and metabolism, confirming the strategy’s effectiveness. In comparison, only 60% of the control group showed minor gains, revealing the limited impact of their standard nutrition and hydration methods. Correlation analysis confirmed the benefits of optimal nutrition and hydration. A balanced diet was strongly linked with cardiorespiratory improvement (r=0.78, p<0.05) and energy maintenance (r=0.71, p<0.05), suggesting that isotonic drinks and a rational nutrient intake reduce physiological strain and boost cardiovascular and metabolic efficiency.

The results also demonstrated a significant connection between diet, hydration, and performance (table 4).

Experimental group participants showed strong correlations between complex carbohydrate intake and calorie expenditure (r=0.82, p<0.05), as well as average speed (r=0.76, p<0.05).

Hydration status played a critical role in achieving high athletic performance and maintaining the physiological efficiency of the body during prolonged training. The negative correlation between urine osmolarity and average speed (r=-0.68, p<0.05) indicates that even moderate dehydration significantly impairs the speed performance of cyclists. This is further supported by the reduction in the number of calories burned in a dehydrated state, as shown by the strong negative correlation between urine osmolarity and energy expenditure (r=-0.72, p<0.05). These findings suggest that dehydration compromises the body’s ability to efficiently convert energy, thereby negatively impacting overall physical performance.

Regular fluid intake, particularly isotonic drinks, contributed to maintaining an optimal water-electrolyte balance, which supported stable muscle and cardiovascular function. Isotonic drinks not only replaced water lost during exercise but also replenished essential electrolytes such as sodium, potassium, and magnesium. These electrolytes ensured the stability of neuromuscular transmission, supported muscle contraction, and prevented the onset of cramps during intense physical exertion. Participants who adhered to the recommended hydration regimen achieved significantly better results across all physiological parameters, underscoring the importance of proper hydration for sustaining performance and reducing the risks associated with prolonged exercise.

Protein intake also played a significant role in enhancing athletic performance. The negative correlation between protein intake and the TSS (r=-0.64, p<0.05) suggests that protein contributes to reducing the physiological stress caused by prolonged physical exertion. This effect can be attributed to protein’s ability to promote muscle tissue repair by stimulating the synthesis of structural proteins necessary for the regeneration of damaged cells. Adequate protein intake also ensured stable blood amino acid levels, supporting muscle functionality and reducing the risk of microtrauma during intense training sessions.

The overall findings of the study underscore that an integrated approach to nutrition and hydration is a critical factor in improving physical performance and endurance in cyclists. A balanced intake of complex carbohydrates, which provide a stable energy supply, and proteins, which facilitate muscle tissue repair, combined with the regulated use of isotonic drinks, helps maintain water and electrolyte balance at an optimal level. This approach reduces physiological stress, mitigates the negative effects of dehydration, and enhances cardiorespiratory adaptation, ultimately contributing to improved athletic performance and endurance.

Discussion

The results of the study demonstrated that a balanced diet with an optimal macronutrient ratio (53% carbohydrates, 27% fats, 20% proteins) significantly enhances the physical endurance of cyclists. The experimental group achieved a 12% increase in average speed, compared to only a 4% increase in the control group, which consumed a diet high in simple carbohydrates (42%). This finding aligns with the work of Matusiak-Wieczorek et al.9, who emphasised the importance of increased complex carbohydrate intake for maintaining stable muscle performance. Similarly, Kreutzer et al.10 noted that a carbohydrate intake of 40% can also be effective; however, their data suggest that such an approach does not guarantee a stable energy supply during prolonged training sessions. The absence of energy declines in the experimental group further supports the conclusion that the proposed macronutrient ratio is optimal.

Adherence to a diet with 20% protein in the experimental group resulted in significant improvements in muscle recovery, reflected in a 9% reduction in the TSS. This finding is consistent with the conclusions of King and Hall,11 who highlighted the critical role of protein in preventing muscle fatigue and supporting anabolic processes. Conversely, Nichols12 argued that a protein intake of 15% is sufficient for athletes; however, the present data suggest that such a level may limit the body’s adaptive capabilities during prolonged physical exertion. Observations in the control group, where the protein content of the diet was only 13%, revealed significantly higher levels of muscle fatigue and reduced overall endurance. This reinforces the advantages of a higher protein intake for maintaining physical performance. A protein-rich diet not only reduces physiological stress but also ensures more stable results, particularly under conditions of prolonged physical exertion.

A 27% intake of polyunsaturated fats in the experimental group supported energy balance and reduced exercise fatigue. This aligns with findings by Kour and Kulkarni¹³ and Ceylan¹⁴ on the role of such fats in energy metabolism. Ponce et al.¹⁵ argue for a higher fat intake (35%) for endurance benefits, but this was linked to elevated inflammation in the control group, whose 34% fat intake impaired adaptation. Thus, a 27% fat level appears optimal for balancing energy efficiency and inflammation control.

Urine osmolarity was lower in the experimental group (732±28 mOsm/kg) than in the control (853±35 mOsm/kg), indicating better hydration due to isotonic drink use. Pereira et al.¹⁶ stress the value of isotonic drinks for hydration under exertion. Though Antonio et al.¹⁷ note that water also hydrates, control group members lost more weight (2.1% vs. 0.9%), affirming isotonic drinks’ effectiveness in fluid and electrolyte replenishment.

A strong correlation (r=0.82, p<0.05) between complex carbohydrates and exercise duration confirms their endurance benefits, consistent with Gordon et al.¹⁸. Woźniak et al.¹⁹, however, advocate simple carbohydrates for short bursts of activity. Still, complex carbs better prevent energy drops, favoring them for endurance sports.

Antonucci²⁰ and Roychoudhury et al.²¹ both highlight the need for personalised nutrition to reduce fatigue and match athletes’ metabolic needs. These perspectives support this study’s call for tailored dietary and hydration strategies.

Although Bonnar and Roberts²² suggest food alone can supply electrolytes, the control group’s sodium decline on plain water challenges this, reinforcing isotonic drinks as a more effective solution during intense exercise.

The experimental group demonstrated stable electrolyte levels (sodium: 139.5±2.3 mmol/l; potassium: 4.1±0.2 mmol/l), which reduced the risk of cramping and improved muscle function. Kahraman23 supports the critical importance of maintaining electrolyte balance for effective muscle activity and preventing dehydration.

The negative correlation between protein intake and TSS (r=-0.64, p<0.05) highlights the essential role of protein in reducing physiological stress during prolonged physical exertion. Solly et al.24 confirm the significant anabolic effects of protein, which contribute to reducing the stress load on the body. Conversely, Helm et al.25 suggests that protein influences only limited aspects of physical stress, particularly muscle fatigue, without providing systemic adaptation. However, the results of this study demonstrate that optimal protein intake in the experimental group not only improved regenerative processes but also reduced overall fatigue, making protein a critical component of sports nutrition.

The negative correlation between urine osmolarity and training duration (r=-0.72, p<0.05) further emphasises the crucial role of optimal hydration in maintaining physical performance. Navalta et al.26 identify urine osmolarity as a sensitive and accurate marker of dehydration, enabling timely assessment of an athlete’s hydration status. At the same time, Fernández-Lázaro et al.27 caution that osmolarity may not fully reflect hydration status under varying temperature conditions or physical states. Nonetheless, the results from the experimental group demonstrate that maintaining low osmolarity through the use of isotonic drinks ensured stable performance levels and reduced the risk of dehydration, even during intense training sessions.

The results underscore the importance of integrated nutrition and hydration strategies for optimal athletic performance. Studies by Yan28, Rothschild et al.29, and Sak et al.30 highlight the need for diet planning that matches the demands of physical exertion. These authors stress the value of combining a balanced diet with personalised hydration to sustain stable performance, even during prolonged training cycles.31

However, several limitations should be noted. The study lasted only eight weeks, which may not reveal long-term physiological changes or side effects. Future research should adopt longer interventions. The lack of blinding may have introduced performance bias, especially in the experimental group, where awareness of receiving a specialised regimen could have boosted motivation via placebo effects. Additionally, the absence of a placebo in the control group limits the ability to isolate true physiological effects. Lastly, although both sexes were included, data were not analysed separately, potentially obscuring sex-specific responses in metabolism, hydration, and hormonal regulation. Future studies should address these issues to enhance the generalisability of the findings.

The data presented in this study detail the mechanisms through which key dietary components – such as complex carbohydrates, polyunsaturated fats, and high-quality proteins – positively influence sports performance. These findings confirm their vital role in stabilising energy processes, supporting muscle regeneration, and reducing physiological stress during prolonged physical exertion.

Conclusions

The analysis of the study revealed that a balanced diet and proper hydration strategies significantly enhance the physical endurance and performance of cyclists. Participants in the experimental group followed an optimally balanced macronutrient composition (53% carbohydrates, 27% fats, 20% proteins), which effectively met the demands of increased endurance. In contrast, the control group adhered to a less balanced diet, with excessive amounts of simple carbohydrates (42%) and fats (34%), which negatively impacted their physical performance.

The experimental group achieved a 12% increase in average training speed (27.2±1.8 km/h), compared to only a 4% increase in the control group. Additionally, the duration of training to fatigue increased by 18% in the experimental group (65±5 minutes) versus just 6% in the control group (54±6 minutes). These results confirm that the consumption of complex carbohydrates and high-quality proteins provides a stable energy supply and supports effective muscle regeneration.

Hydration strategies also had a significant impact. Participants in the experimental group who consumed isotonic drinks-maintained sodium levels at 139.5±2.3 mmol/L, with weight loss limited to 0.9±0.1%. In the control group, sodium levels dropped to 135.8±2.7 mmol/L, and weight loss increased to 2.1±0.2%, indicating more severe dehydration. Urine osmolarity further illustrated this difference, with the experimental group maintaining a level of 732±28 mOsm/kg, signifying adequate hydration, while the control group showed a higher osmolarity of 853±35 mOsm/kg, reflecting a fluid deficit.

Correlation analysis revealed a strong relationship between a balanced diet, hydration levels, and physical performance. Specifically, complex carbohydrate intake was positively correlated with speed (r=0.76, p<0.05), while dehydration was negatively associated with endurance (r=-0.68, p<0.05). These findings underscore the importance of integrating nutrition and hydration strategies into athletes’ training programmes to enhance physical performance.

The study has several limitations. The small sample size limits the generalisability of the findings to a wider athletic population. The short follow-up period prevents assessment of long-term effects of the nutritional and hydration strategies. Furthermore, the focus on male cyclists restricts applicability to other sports and female athletes.

Future studies should include a more diverse sample in terms of age, gender, training level, and sport. Long-term effects on physical performance and health also warrant further investigation.

Conflicts of interest. The authors declare that there is no conflict of interest.

Authors’ contributions. JL and QL have given substantial contributions to the conception or the design of the manuscript, JW and QC to acquisition, analysis and interpretation of the data. All authors have participated to drafting the manuscript, Jianda Li revised it critically. All authors read and approved the final version of the manuscript.

Ethical Statement. The Ethics Commission of the Shandong Shooting and Bicycle Campaign Management Center, No. 009367, approved the study. Informed consent was obtained from all individuals included in this study.

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