## 5 Feasibility and Acceptability  
In contrast to the wealth of research exploring the efficacy of dietary nitrate (discussed further below), only a handful of studies have reported data on the feasibility and/oracceptability of different strategies for augmenting dietary nitrate intake [34]. In one study by [PERSON] et al. [58], who provided pregnant women with a single 70 mL concentrated beetroot juice'shot' every day for 8 days, almost all of the participants (97%) indicated that they would consume beetroot juice'shots' again, if they were experiencing benefits. However, only 62% reported finding it easy to consume this supplement. In addition, only 54% reported the'shots' to be palatable. In another study, [PERSON] et al. [59] examined the feasibility of consuming low (1 beetroot juice'shot' every second day), medium (1 beetroot juice'shot' every day), and high (2 beetroot juice'shots' every day) doses of concentrated beetroot juice in overweight/obese older adults in a 13-week intervention trial. Self-reported compliance was >90%. However, around 20% of the participants in that study withdrew prior to the end of the trial, with most of the dropouts coming from the moderate- or high-dose groups. Although some of the participants reported finding the taste of the beetroot juice 'pleasant', this was not a universal view, with others noting that the taste was 'bad' and that they had to 'hold [their] nose to gulp it down'. It is noteworthy that three of the participants who withdrew cited GI discomfort as their main reason for dropping out of the study, whilst three additional participants reported withdrawing because they disliked the smell/taste of beetroot juice. In another study conducted in Tanzania, participants who consumed beetroot juice'shots' for 60 days reported the taste to be 'good' or'very good', and compliance with the intervention was >90% [60]. Nevertheless, the findings from both [PERSON] et al. [58] and [PERSON] et al. [59] suggest that, at least for some individuals, more palatable alternatives to beetroot juice may be required to help some individuals elevate their nitrate intake. Other nitrate-containing supplements, such as beetroot-containing pills/capsules or nitrate-rich gels, could represent a more acceptable strategy to increase nitrate intake in individuals who do not like the taste of beetroot juice. In addition, the variety of options available with nitrate-rich vegetables (see Table 1 for some examples) could help reduce the risk of taste fatigue/monotony and allow individuals to self-select vegetables that fit better with their own food/taste preferences. This could, theoretically, help improve longer-term compliance. Very high compliance (97-98%) was reported in 2 studies lasting 4-5 weeks, which used nitrate-rich vegetables as a nitrate source [61; 62]. Meanwhile, in a study by [PERSON] et al. [63], in which participants consumed four different nitrate-containing beverages--a sodium nitrate solution, concentrated beetroot juice, a rocket salad beverage, and a spinach beverage--ingestion of all four beverages was generally well tolerated. However, GI complaints were reported by two participants following consumption of the rocket salad beverage and by one participant following consumption of the spinach beverage, which was believed to be related to the high volume of these supplements provided (which was greater than for the beetroot juice and sodium nitrate conditions). In another study from the same group, participants increased their intake of dietary nitrate through either concentrated beetroot juice or whole vegetables over a 1-week period [64]. Both interventions were well tolerated, with no adverse events reported. Participants reported 100% compliance with the beetroot juice intervention, and consumed an average of 241 g/d nitrate-rich vegetables, which was close to their daily target of 250 g/d, suggesting that it is feasible to increase nitrate intake through both vegetables and nitrate-rich beetroot juice [64].