Nutritional Strategies for Olympic Biathletes: A Practical Review

This article is a narrative review. We selected this typology because of the very limited number of biathlon-specific nutrition and supplementation studies, which precludes a systematic review or meta-analysis. A narrative approach allows integration of evidence from related endurance sports (e.g., cross-country skiing, cycling, triathlon) where appropriate, combined with practical insights into the dual performance demands of biathlon.

This review was conducted as a narrative synthesis. Using the search terms ‘biathlon AND nutrition’, ‘biathlon AND supplementation’, and ‘biathlon AND physiology’, we searched PubMed and Google Scholar for studies published by December 2024. Due to the limited number of biathlon-specific publications, studies from closely related endurance sports (e.g., cross-country skiing, cycling and triathlon) that addressed topics relevant to biathlon training or competition were also included. The inclusion criteria comprised peer-reviewed articles in English reporting on nutrition, supplementation, energy expenditure, recovery or environmental challenges in endurance sports. Non-peer-reviewed materials, case reports without nutritional relevance and studies unrelated to endurance or precision performance were excluded.

The review sub-topics (energy requirements, macronutrients, micronutrients, physique, race-day nutrition, cold and altitude, and supplements) were chosen in advance based on the main areas highlighted in international position statements on sports nutrition. These were then adapted to reflect the unique dual requirements of biathlon: high aerobic output during skiing combined with neuromuscular precision and psychological control during shooting.

Biathletes complete a very differentiated training programme, consisting of skiing, roller skiing or cycling, shooting sessions, and gym or cross-training, which demands wide energy needs. Moreover, the energy requirements depend on training volume and intensity, growth, goals (e.g., change in body mass/fat mass) and other lifestyle activities. In biathlon, training and competition are entirely different in duration and intensity. While competition for the biathletes lasts around 20–50 min with high-intensity effort separated by shooting, trainings usually have lower intensity but lasts around 2–4 h. To date, no single study accesses energy expenditure in biathletes. A study conducted on cross-country skiers show that the daily energy expenditure during the preparation period, which often includes two training sessions per day, is 4800–6000 kcal/d [7]. In contrast, during intense, on-snow training, it has been observed to be 950–1900 kcal/d higher [7]. The respective figures for male and female athletes are approximately 7149 kcal/day and 4357 kcal/day [8]. Cross-country skiers are recommended to consume 55–75 kcal/kg/d, with the quantity depending on the individual’s needs [9]. It is important to note that, although cross-country skiers and biathletes both run on skis, the additional weight of the rifle on the back of the biathlete’s back introduces a different set of physical demands. Compared to cross-country skiing, carrying a rifle (which represents an additional load of approximately 4 kg) while skiing incurs an average cost of approximately 7% higher [10]. Although extrapolation from cross-country skiing provides a useful starting point, the lack of direct measurements of energy expenditure in biathlon, especially under race conditions, remains a critical gap.

As is the case in numerous other endurance sports with considerable energy demands, there is also a risk of low energy availability (LEA) in biathlon. This arises from a discrepancy between energy expenditure and energy intake, whereby the former exceeds the latter to such an extent that it cannot provide the requisite energy to support the functions necessary for maintaining optimal health and performance [11]. A consequence of prolonged energy deficiency in athletes (EDA) is relative energy deficiency in sports (RED-S). REDs have numerous adverse implications for health and performance. These include impaired immunity, reproductive function, glycogen resynthesis, and cardiovascular and haematological health issues. Additionally, REDs can cause sleep disturbances, impair growth and development, and reduce training response and performance, including endurance, power and strength, or motivation [12]. The only study conducted on cross-country skiers indicates that athletes encounter challenges in meeting their energy and carbohydrate requirements during a training camp. Despite the mean energy availability being 40.3 ± 17.3 kcal/kg FFM/d, which is above the previously established universal cut-off limit for women (>30 kcal/kg FFM/d), the range for athletes in this research was 11.1–78.4 kcal/kg FFM/d [13]. To determine the risk of LEA in athletes with greater expediency, medical practitioners or nutritionists may utilise validated questionnaires, namely the LEAF-Q and LEAM-Q, which have been developed for women and men, respectively [14,15].

Most biathletes’ key training sessions are performed at intensities highly dependent on carbohydrate (CHO) based fuels for muscle metabolism. Biathletes typically undertake two training sessions per day, including roller skiing, cycling, cross-country skiing, strength training, cross or yoga. The diverse nature of these sessions gives rise to differing carbohydrate requirements. It is, therefore, essential that nutrition aligns with the specifics of the training plan, considering each session’s duration, intensity and objective, to provide the necessary fuel for the work required. According to current recommendations, biathletes should consume 6–12 g/kg/d of carbohydrate, depending on their training programme [16]. This should facilitate the replenishment of muscle glycogen when required. Table 1 and Table 2 demonstrate the carbohydrate-dependent training programmes and how the total carbohydrate intake could be distributed over the sample week and within a day to guarantee high carbohydrate availability for the most important training sessions during the summer and winter training periods. These tables illustrate an adapted framework for nutritional periodisation in biathlon. While they are based on established endurance nutrition guidelines, they also consider sport-specific factors, such as the repeated transitions between high-intensity exertion and precise shooting. Some training sessions may be carried out with a reduced carbohydrate availability to expose the muscle to a greater training stimulus and, consequently, promote a more significant metabolic adaptation. For more details see [13,14]. It is important to note that training with low glycogen availability is associated with an increased risk of illness [17], injury [18], and overtraining [19].

Furthermore, reduced training intensity and/or volume [20,21] and impaired post-exercise muscle protein synthesis regulation [22] have been observed. Moreover, a recent meta-analysis of nine studies examining the long-term benefits of carbohydrate periodisation on performance outcomes indicates that this approach may not consistently enhance performance compared to training with high carbohydrate availability [23]. The collective evidence suggests that training with reduced carbohydrate availability may be constrained due to reduced training duration and/or intensity. However, this may not apply to individuals seeking the most time-efficient training. Therefore, although these strategies can be used selectively, they cannot be routinely recommended to biathletes until studies specific to the sport confirm their long-term benefits.

During the season, biathletes are required to spend a significant amount of time at training camps or travelling to and from competitions. This often results in limited access to the kitchen facilities, which can impact their ability to meet dietary recommendations. To ensure adequate carbohydrate intake, it is essential to incorporate carbohydrate-rich foods at meals when possible and provide high-carbohydrate snacks between meals, particularly on days with elevated energy expenditure and/or intense physical activity. Furthermore, it is important to guarantee the intake of carbohydrates both before and during exercise, as well as during the subsequent recovery period.

The duration of biathlon training sessions typically exceeds 90 min, which, per the recommendations for endurance athletes, necessitates the provision of carbohydrates [24]. Based on the recommendation for athletes, biathletes should consume 30–90 g of carbohydrates, depending on the training intensity and duration [25]. The primary carbohydrate source for athletes undertaking exercise should be an isotonic drink, which also improves hydration status. During winter, isotonic drinks might be kept warm in insulated containers. In addition, biathletes may consume an energy bar or gel, such as a banana or jelly bar, during short breaks in training. The current studies indicate no significant difference in oxidation rates between isotonic drinks, bars, and gels [26,27]. Therefore, athletes can select the product that aligns with their preferences. The ingestion of carbohydrates during exercise benefits exercise performance [28]. Moreover, consuming carbohydrates during prolonged and/or high-intensity exercise may help to counteract the reduction in immune system activity and reduce the risk of illness, which is particularly important for winter sports [29].

A typical biathlete engages in two training sessions daily, with an interval of 4–6 h between sessions. This gap is shorter than in other disciplines, such as triathlon (5–7 h) [30] and cycling, where there is usually only one training session a day. The complete replenishment of glycogen stores occurs within a 24 h [31]. Given the brief interval between training sessions, biathletes are advised to prioritise recovery immediately following each session. It is recommended that 1.2 g/kg of CHO be consumed immediately after exercise [32]. In instances where the CHO intake is insufficient, administering 0.3 g/kg of protein has been demonstrated to enhance glycogen resynthesis rates [33]. Moreover, whey hydrolysate appears to be more effective in this regard than other types of protein and the production procedure [34,35]. The initial timing of the post-exercise meal is of particular significance, as evidence suggests that the rate of muscle glycogen synthesis is accelerated during the initial 2 h following exercise compared to the subsequent hours [36]. From a practical standpoint, a recovery shake is a suitable option for athletes needing a post-training refuelling strategy. The shake should contain milk, banana, protein powder, and other low-fibre fruits or cereals tailored to the athlete’s needs. This can be easily transported and consumed immediately following training.

Protein is typically linked to high muscle mass and is regarded as the most crucial macronutrient for power sports. Nevertheless, endurance athletes must also prioritise protein intake for optimal training adaptations. Current research indicates that 1.6 g/kg of body mass per day is adequate for muscle development [37,38,39]. Moreover, it is advised that biathletes engaged in twice-daily training programmes adhere to the current guidelines for the timing of protein intake. This should be at a rate of 0.3 g/kg BM of protein (~20–25 g of high-quality protein) immediately following a key training, resistance exercise, or race. This ensures that the early protein synthetic response to the training stimulus is optimised [40,41]. It is noteworthy that the intake of protein (approximately 20–25 g) while carbohydrate intake is inadequate (<1.2 g/kg) has been observed to enhance glycogen resynthesis [33]. It should be noted that the recommended intake of ~1.6 g·kg⁻¹·d⁻¹ is extrapolated from endurance athletes in general. Furthermore, no study has investigated the timing or dosage of protein intake specifically in biathlon, nor has any study verified whether the timing or distribution of protein intake affects recovery and shooting performance in biathletes. Given the dual demands of muscle recovery and maintaining lean body mass throughout a long season, biathletes may benefit from a more strategic approach to protein intake. This hypothesis requires direct testing.

Vitamins and minerals are essential nutrients for maintaining optimal performance. It is widely acknowledged that deficiencies in these nutrients can adversely affect overall health and bodily functions. However, deficiencies are not commonly observed due to the high caloric intake typical of biathletes. It appears that, provided athletes consume a typical diet, they obtain sufficient nutrients. The primary concerns regarding micronutrient status are generally limited to iron and vitamin D. These findings are typically associated with restrained eating practices and inadequate food variety.

Iron is a micronutrient that is essential for oxygen delivery within the body. A decline in iron levels has been observed to impair athletic performance, with the underlying mechanism thought to be related to the role of iron in oxygen transport [42]. Furthermore, iron deficiency is frequently observed in athletes engaged in endurance sports, with female athletes demonstrating a higher prevalence of this condition than males [43,44]. The reason for that is complex, but the most common include low energy intake, vegetarian diets and endurance exercise [44,45]. It is therefore crucial to monitor athletes’ iron status regularly through specific blood markers, including ferritin, haemoglobin concentration and transferrin saturation [46]. It is a common practice in endurance sports to provide additional iron supplementation even when the level is within the recommended range. However, no evidence suggests that such supplementation improves endurance performance in athletes who do not have iron deficiency [47,48,49]. Athletes must pay close attention to their iron intake, ensuring they consume sufficient quantities of meat, fish, legumes, dark green vegetables, nuts and seeds. The current recommended intake for elemental iron is 8 mg for males and 18 mg for females [50]. Nevertheless, recommendations for the general population may prove inadequate for athletes [46].

A suboptimal level of vitamin D is a prevalent phenomenon among the general population on a global scale. It is typical for levels to be lower during winter and among athletes who train indoors instead of outdoors. Given the role of vitamin D as a gene modulator, it is recommended that the level be sustained at >50 nmol/L [51] to maintain optimal immune function, bone health and the rehabilitation process. If exposure to sunlight is inadequate, as well as dietary intake, athletes may use vitamin D supplementation to cover their needs. Athletes with insufficient status require supplementation with 2000–4000 IU/day vitamin D to keep 25(OH)D concentrations in the sufficient range [52].

Although iron and vitamin D deficiencies are well documented among endurance athletes, there is no longitudinal data available for elite biathletes. Therefore, supplementation practices are largely empirical rather than evidence-based.

Caffeine is the most popular stimulant and has been shown to improve performance by reducing fatigue and enabling sustained power output. The effect of caffeine supplementation varies depending on the athlete’s genotype. Some individuals are non-responders, and others may react negatively to caffeine ingestion. Current recommendations suggest intakes of 3–6 mg/kg body mass [72], usually 30–60 min before competition. Studies conducted in cross-country skiing have shown reduced time to complete a set distance [73] and improved time to task failure [74]. However, caffeine supplementation negatively affected shooting performance during simulated biathlon competitions and tended to improve skiing performance [75]. This highlights that direct transfer of findings from other endurance sports can be misleading if the unique precision demands of biathlon are ignored.

Long-term (4 to 24 weeks) supplementation with ß-alanine (4–6 g/d) increases muscle carnosine content [76], which improves buffering capacity [77]. Beta-alanine supplementation improves high-intensity endurance performance across a range of exercise capacity tests, fixed duration and intermittent exercise tasks, typically 30 s to 10 min in duration [77]. Although biathlon events last longer than 10 min, beta-alanine supplementation improves performance when high-intensity effort(s) are performed within or at the end of prolonged exercise. Long-term supplementation (up to 24 weeks) is safe; paraesthesia is the only side effect.

Creatine is the most studied ergogenic supplement with a wide range of uses. One benefit is improving sprinting during or after endurance exercise, typical of biathlon competitions. Creatine supplementation increases power output and speed, reducing fatigue and the time needed to complete a given distance [78]. However, one of the side effects is rapid weight gain, which can be detrimental to biathletes’ performance, especially during ascents. It is recommended to take 3–5 g of monohydrated creatine daily.

Prior to the Single Mixed Relay, the shortest biathlon event, athletes can use bicarbonate supplementation. Bicarbonate is an endogenously produced extracellular anion that works by removing excess hydrogen ions produced during high-intensity exercise and, to some extent, supports the body’s ability to meet the high rates of energy demand required to maintain muscle contractile function during such activity. Oral ingestion of 200 and 300 mg/kg BM of sodium bicarbonate is sufficient to increase endogenous bicarbonate levels, which can improve performance by 2–3% during single or repeated bouts of high-intensity exercise, typically lasting 1–10 min [79,80,81]. However, it should be noted that there is a high risk of gastrointestinal upset with bicarbonate supplementation.

Nitrate supplementation has a wide range of effects on health and performance. From an athlete’s perspective, it may regulate blood pressure and blood flow, mitochondrial respiration, muscle contraction and immune function. Nitrate supplementation can improve running efficiency by reducing the absolute O₂ cost for a given work rate [82] and improve endurance performance [83]. The full ergogenic effect and mechanism of action of nitrate supplementation are described elsewhere [84,85]. Taking a dose of 6–8 mmol (~350–500 mg) of nitrate (1–2 commercially available tablets) 2–3 h before the race, with or without supplementation for 3–7 days before the competition. However, it should be added that in well-trained athletes with VO₂peak values >64.9 mL/kg/min, the improvement is not observed. It is worth reconsidering the supplementation strategy during training or less important races because of possible gastrointestinal side effects. It is advisable to avoid using mouthwash or chewing gum containing beetroot juice, as they may interfere with its benefits.

During the season, biathletes take part in nine World Cup competitions. Each of these takes place in a different location, so they sleep in a different hotel each time. Based on the preliminary research, some evidence supports the use of tart cherry to improve sleep duration and efficiency, presumably as an important source of melatonin [86]. In addition, tart cherry may be beneficial when repeated performance is required within a day or over several days, such as in biathlon [87]. Taking 45–100 cherry equivalents (e.g., 30 mL tart cherry juice) twice a day for 4–7 days before and during the competition period is recommended.

An important consideration in biathlon is that nutritional and supplementation strategies may not consistently affect the two key performance factors: skiing speed and shooting accuracy. As we mentioned above, caffeine is known to improve endurance by reducing perceived exertion and sustaining power output. However, the only study conducted in biathlon revealed impaired shooting accuracy despite improved skiing times. This illustrates a unique challenge in biathlon: a supplement that improves aerobic capacity may also compromise fine motor precision. Other ergogenic aids, such as nitrates, creatine and β-alanine, have primarily been studied in the context of endurance or intermittent high-intensity activities, and they may offer potential benefits for skiing. However, their influence on shooting performance remains unknown. Conversely, supplements that promote neuromuscular stability, reduce tremor or improve sleep quality (e.g., tart cherry juice, which contains melatonin) could indirectly support shooting performance, but the evidence is preliminary. Therefore, a cautious and individualised approach is required in biathlon, where both endurance and precision outcomes must be evaluated before practical recommendations can be made.

Moreover, it is important to remember that the use of dietary supplements is associated with the risk of a positive doping test. To minimise this risk, choosing supplements with a specific certificate, such as the Informed-Sport certificate or supplements included in the Cologne List, is advisable.