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SPECIAL EDITION 5 must-read research reviews on Nutrition

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Page Number

Section

Link to Abstract Review Title

Study Details

Practical Takeaways from study

Related links to learn more about the topic

Reviewers comments on the study

Nutrition

[Abstract]

Oral health and nutrition: the importance of looking after your mouth OBJECTIVE Poor oral health is common in elite athletes . Reports from the London 2012 Olympic games show 55% of athletes with dental caries, 45% with dental erosion and 28% were bothered by their oral health (see article below). One key determinant of oral health particularly amongst athletes, is nutrition and the frequent consumption of carbohydrate -containing, acidic sports drinks and supplements as well as their eating behaviours. Poor oral health negatively affects training and performance of athletes by inducing pain, reducing well-being and quality of life, and increasing whole-body inflammation. This call to action is to recommend strategies to improve oral health in athletes. WHAT THEY DID The authors declared a call to action regarding the oral health of athletes, targeting both athletes and health professionals (nutritionists and dietitians, sport and exercise medicine practitioners, dental professionals, scientists in related field, sport policy organisations and industry) in their statement piece. This involved developing strategies to reduce the risk of possible adverse oral effects, whilst maintaining the performance benefits. WHAT THEY FOUND A consistent finding in previous published studies is that oral health is poor amongst athletes, especially considering younger participants (both selected samples attending dental clinics or more representative evaluations of teams) (see HERE). The proportion of athletes affected by dental caries were 15-75%, moderate-tosevere infections around wisdom teeth were 15%, tooth wear was 36-85%, and gum diseases were 5–39%. In addition, dental trauma was reported by 14-57% of athletes in at-risk sports. This statement concludes with recommendations to guide the improvement of oral health in elite athletes (see practical applications and infographic below).

Practical Takeaways It is important to establish strategies to reduce the risk of possible adverse effects of poor oral health, whilst also maintaining performance benefits. Take home messages to support a good oral health among recreational exercisers and athletes include: 

Avoid the use of beverages and supplements containing sugars (which are linked to poor oral health) outside of a specific training regimen or competition when prescribed by a qualified nutritionist and identify suitable alternatives. For instance, milk could be substituted for a proprietary sports drink in post-competition.

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Where carbohydrate or acidic supplements are used regularly, highconcentration fluoride toothpastes (minimum 1350 parts per million) should be substituted for standard toothpastes twice a day. It is advised that athletes spit but do not rinse after toothbrushing to maximise the benefit of the fluoride availability.

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Use of interdental brushes and floss before tooth brushing to reduce dental plaque.

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Routine periodic oral health assessment (twice-yearly) and personalised coaching/instructions by a dental professional.

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Where possible, use a two-bottle strategy. For example, if you are having a sport supplement followed by drinking water. For more information about athlete’s practices on oral health (see video below).

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James’s Comments “It is important to highlight that some of these practical applications are more feasible depending on behavioural changes and adherence to care, which are particularly difficult to change. As such, in order to improve and sustain good oral care, oral health should be an integral area within aspects of health promotions and interrelationships within their sport and peer networks. The authors reported that literature on oral health is limited and studies are needed to identify the best approaches for the implementation of these practical applications in different sport environments. Indeed, regular assessments by a dental professional will allow personalisation of prevention plans and early treatment of any disease. Ultimately, if the bacteria in your mouth is not functioning to the best of its ability then an individual will struggle to absorb all the nutrients we require.”

Nutrition

[Abstract]

Can milk really help with adaptations following resistance training? OBJECTIVE

WHAT THEY DID

WHAT THEY FOUND

It is well established in adult laboratory trials which exert resistance exercise programmes (see HERE), that the ingestion of carbohydrate and carbohydrate + protein combined, exerts beneficial effects on improving the adaptative response (strength) of muscle during the recovery period.

Overall, 103 students were recruited from a 7-week summer strength and speed camp. Baseline and post-test measures included height, body weight, and strength assessments (bench press, squat, and power clean).

Overall, there was no change in body weight across the training programme and no effect of age, race, or ethnicity on group differences.

Athletes were placed into three training groups: Similar studies in the applied setting and with adolescent participants are currently limited and thus the ability to translate previous work into practice with high-school aged athletes is difficult. Therefore, the aim of this study was to test the effects of a carbohydrate and carbohydrate + protein drink on strength changes in male and female high-school athletes.

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Group 1: junior varsity and varsity females grade 9 to 12 (n = 30).

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Group 2: varsity males’ grade 11 and 12 (n = 43).

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Group 3: junior varsity males’ grade 9 and 10 (n = 30).

The camp was held four days per week (Monday to Thursday) and each day consisted of:

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However, strength showed a significant effect on time across the 7 weeks and group. In particular, the chocolate milk group had a greater improvement in their overall strength score from pre-test to post-test (166.8 ± 73.5 kg to 187.3 ± 75.6 kg) compared to the carbohydrate group pre-test to post-test (179.7 ± 89.5 kg to 184.5 ± 85.5 kg). Interestingly, further analysis of the results showed the chocolate milk group increasing their bench score from pre- to post-test whilst the carbohydrate group decreased their bench from pretest to post-test.

1-h free weight resistance training. 1-h of on-field agility drills and conditioning sprints.

This was followed by ingestion of one dose of the assigned commercially available drink outlined below:

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Carbohydrate: 709.7 ml, carbohydrate 42g, protein 0g, fat 0g, sodium 320, kcal 160. Carbohydrate + protein: 473.1ml, carbohydrate 44g, protein 16g, fat 5g, sodium 360, kcal 300.

Practical Takeaways This work builds on previous studies that have been reviewed in the Performance Digest, showing the beneficial effects of milk on strength adaptations. Practically, milk is a drink that can be added into lunchboxes, back-packs, and on the road to ensure young athletes have a good source of protein which can be drunk when required. Further, the results from this study show the importance of working with commercial partners of high schools as well as key stake holders including coaches. In particular, during the planning stages of training programmes to ensure developments and adaptations from resistancebased training programmes are nutritionally supported. Overall, the benefits of consuming dairy should be well considered for any training programme and is discussed in depth in the podcast below.

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James’ Comments “I really like this paper for a number of reasons. Firstly, the study has taken traditional laboratory-based studies into the applied setting to re-test the hypothesis. For any coaches working with young athletes who are trying to develop physical qualities over summer breaks, then the implementation of a cholate-based milk into the recovery strategy has to be performed. Secondly, the study uses a drink that is globally available for consumption by adolescent athletes of all ages, can be purchased relatively cheaply in most shops, and service stations when on the road – a real practical advantage. Finally, chocolate milk is something I have used for years with rugby players, football players, and boxers. Milk is one of the most nutritionally complete beverages and, in my opinion, is one of the go-to drinks for recovery following exercise or overnight - the farmers in the video below feel the same too.”

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Nutrition

[Abstract]

The importance of nutritional intake during the acute stages of ACL recovery OBJECTIVE

WHAT THEY DID

WHAT THEY FOUND

Anterior cruciate ligament (ACL) injuries are common among team-sport athletes, often resulting in surgical reconstruction. During the progressive recovery phases following this reconstruction, athletes are likely to experience different energy expenditures, and as such, nutritional intakes should be tailored to each phase in order to maximise recovery. Indeed, previous work has shown whole-body fat-free mass losses of 5.8 kg in the first 8 weeks of rehabilitation (refer to the article below), highlighting the importance of adequate nutritional intake to minimise losses in muscle mass.

The soccer player was 23 years old, body mass 77 kg, height 179 cm, internationally capped, and was competing in the English Premier League at the time of the study. The player had been a full-time professional since the age of 18, engaging in daily structured soccer-specific training for more than 5 years.

Nutrition:

The aim of this case-study was to quantify the energy expenditure (using the gold standard method of doubly labelled water) and daily energy intake during a 7-day training week occurring 6 weeks after surgery from a single soccer player. The authors also present whole-body and regional changes in body composition during the rehabilitation period (38-weeks).

injury and 12-, 18-, 28- and 38-weeks following surgery.

The following variables were assessed throughout the study period:

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Whole-body DXA assessment 6 days prior to the

Energy expenditure via the doubly labelled water method. Energy and macronutrient intakes reported in week 6

Practical Takeaways The results of this case-study provide great insights into the energetic cost of repairing injured tissues. Indeed, how many athletes going through rehabilitation from injury, lower their total daily energy intake, and as such, decrease carbohydrate and protein intakes because of concerns regarding unfavourable body composition changes, for example, gaining fat mass? The results of this study show the importance of matching nutritional intake to the expenditure demands placed on the injured athlete. For example, in this case study, the player was in a mean deficit in 6 of the 7 days (energy expenditure: 3178 versus 2765 kcal.d-1), possibly slowing down the recovery process during his rehabilitation. Over many weeks, injured athletes can actually spend more time at the training facility, more time in the gym, and more time receiving treatment than non-injured athletes. These extra demands can result in increased energy expenditures, with the injured player in this case-study actually expending 300 kcal.d-1 more than that a non-injured goalkeeper from the same team (see HERE). To this end, practitioners working with athletes during rehabilitation should individually plan a nutritional strategy that aligns closely with the progressive phases of recovery and therefore increases in energy expenditure.

Interestingly, the mean daily energy expenditure during this period equated to 3178 kcal.d-1, thus highlighting that the player was likely in an energy deficit on 6 of the 7 days. Anthropometric Developments:

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by remote food photographic method, 7-day food diaries, and daily 24 h recalls. The player’s ‘typical day’ started at 8:30 am ending at 4 pm (Monday-Saturday) and included a comprehensive rehabilitation programme which can be viewed in Table 1 within the main manuscript (see Abstract link above). Sunday represented a non-training day.

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The player adopted a skewed approach to feeding where energy and macronutrients were consumed in a hierarchical order of dinner, lunch, breakfast, and snacks. Irrespective of the order of nutritional intake, the player was successful in achieving the prescribed daily energy intake on 4 of the 7 days, where mean daily energy intake was 2765 ± 747 kcal.d-1.

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During the first 6 weeks, total body mass decreased by 1.9 kg, including a loss of 0.6 kg and 1.2 kg of fat-free mass and fat mass, respectively. In particular, the injured and non-injured leg lost 0.9 kg and 0.6 kg of fat- free mass, respectively. Between weeks 7-38, fat-free mass increased by 1.0 kg in both the non-injured and injured legs, largely due to the fact the player had been advised to increase daily energy intake. This also resulted in an increase of 0.7 kg of whole-body fat mass.

James’ Comments “Case-studies, in particular, those that are performed on injured athletes, tend to always lack power of sample size. However, credit should be given to Anderson and colleagues on collecting gold standard energy expenditure data and very tightly controlled energy intake data throughout a specific week during rehabilitation. The results of this study provide readers (and me) with really powerful take-home messages regarding the importance of nutritional intake and recovery from surgical injury. During this recovery phase, the energetic cost of repairing injured tissue is high and advising players to decrease total energy intake too much may actually prolong the total duration of the rehabilitation period and have a negative effect on the rehabilitation of your athlete. In my own experience, the rehabilitation period is a time in an athlete’s career where education around energy balance, meal timing, meal composition (further information in the podcast and infographic below), and overall importance of nutritional intake can really be embedded. Lastly, the successful return-to-play projects I have personally worked on have always been performed by working closely with the medical team and this would be highly recommended to readers.”

Nutrition

[Abstract]

How can nutrition support rehabilitation from patella tendinopathy? OBJECTIVE

WHAT THEY DID

WHAT THEY FOUND

Patellar tendinopathy (PT) is a common musculoskeletal injury in those athletes from jumping sports. Interestingly in professional basketball, up to 52% of players have reported patella tendon pain that has limited performance.

In this case study, the authors identified a 21 yr old basketball player who had undergone an MRI scan and presented with PT. The player was still playing as part of an active team, although both player and support staff focused on stress relaxation loading consisting of leg extension, leg press, and Spanish squats progressively increasing over the 18 month programme.

The main findings of the article included:

The author of this paper discusses the advantages of stress relaxation within the tendon, however, for the purpose of this article, the focus is on the nutritional aspects of how collagen and vitamin C can support rehabilitation from patella tendinopathy. As such, the objective of this study was to understand the beneficial effects of stress relaxation loading, combined with a nutrition intervention, on body composition, strength, and pain from a single basketball player who had experienced knee pain for ~5 yr.

The player reported following his normal nutritional intake throughout the programme, however, the intervention involved additional consumption of 15 g of gelatin with ~225mg vitamin C. Body composition assessment was recorded via sum of seven skinfolds, whilst strength assessment was determined using an isokinetic dynamometer.

Practical Takeaways From the results of this case study and reading the authors reflections, it is evident that: 

Providing the correct substrates (15 g gelatin with 225 mg of vitamin C) 1 h before loading maximises the ability of targeted area to increase collagen synthesis.

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The success of the programme is only as effective as the buy-in from both the athlete and support staff as a multi-disciplinary team.

For the readers, this is a recipe that I have used before and adapted from the author of this paper: ⇒

84 g Gelatin (Dr Oker) – any major supermarket in the cake isle

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50 ml of OJ or Ribena

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Handful of mixed berries

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300 ml hot water

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Bodyweight showed minimal change over the 18month period, although there was a small decrease in body fat percentage from 8.4% to 5.9%.

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Maximal single-leg isometric hamstring strength increased 196%, isometric leg extension strength increased by 156%, and leg press strength increase 187.5% over the course of the programme.

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In regard to the PT, MRI images following the programme showed a progressive decrease in MRI reactivity and was supported by a blinded orthopaedic surgeon declaring the PT “normal” following a third and final scan 18 months after the programme. This was highlighted by decreases in the self reported pain and tenderness from the player. In additon to this, at the point of the final scan, the athlete was pain free and playing more than 25 min each game.

James’ Comments “Although this is a case study, the translational potential of this to any practitioner working in sport is huge and follows similar results as seen previously (refer to infographic below). The authors show a clear structured programme of combining both load and nutrition, to create a really positive outcome for an injured player who buys into the process. I have personally followed similar strategies with a rugby player coming back from an ACL rupture, using the recipe above, and saw a quicker than normal return-toplay. Considering the research in this area is still in its infancy, there are going to be critics who are not fully convinced just yet. However, are there any negative effects to consuming gelatine and vitamin C and hour before exercise? Keith Barr (see video below) and the systematic review (see article below) would suggest not. My advice would be to use strategies outlined in the practical takeaways to prevent and protect soft tissues, before an injury actually occurs, especially with those high-risk athletes.”

Nutrition

[Abstract]

Nutritional strategies to enhance performance of strength and power athletes OBJECTIVE

WHAT THEY DID

WHAT THEY FOUND

Periodisation is a concept most athlete support staff will use to shape exercise programmes. However, in recent years, “nutritional” periodisation has become a popular strategy, to support and optimise exercise performance and body composition throughout athlete training sessions and competitions.

For the purpose of this review, strength and power athletes were classified as those for whom performance is strictly defined by measures of strength and power, for example, powerlifting, weightlifting, and shot put.

The authors provide a great table which I have re-drawn and included as an attached document (see HERE). In summary, the table provides evidence-based recommendations for nutrition modifications geared to accommodate alterations in training load and different body mass-based goals of the athlete.

This review synthesised the current available literature regarding nutritional strategies for strength and power athletes.

In review of the available literature, the authors firstly classified four main themes relating to basic nutrition for strength and power athletes: calories, carbohydrate, protein, and fat. Secondly, the authors discussed seven key variables that need to be considered when developing a periodised nutrition plan: 1)

Increases in training load.

Decreases in training load.

Increases in body mass.

Decreases in body mass.

Competition.

Cutting weight.

Multi-event competitions.

Practical Takeaways This review provides a strong case for the requirement of nutrition plans that match the individual athletes training load, body composition goals, and competition goals. These three key variables are fundamentally important for the practitioner to fully understand from both the coach and athlete point of view and cannot be overlooked by any practitioner. A thorough understanding of these goals will then aid practitioners to then align particular nutritional strategies to achieve such goals. I would recommend that a meeting is scheduled to discuss these goals with both the coach and athlete. For example, if you were unaware that your athlete was trying to reach a particular weight for competition day, but had them consuming creatine and 7-8 g.kg.body mass-1 of carbohydrates, clearly the nutritional plan and goals of the athletes will not align. Likewise, if your athletes are trying to increase body mass during a pre-season period but they are not eating sufficient protein on heavy training days, then muscle hypertrophy will be impaired and thus so will an increase in body mass.

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Competition: Competition strategies will differ dependant on the sport (e.g. weight-making sports vs. strong man). If acute weight loss strategies have been employed, then rehydration and increased glycogen strategies should be followed. Similarly, events that run the whole day or over multiple days should implement carbohydrate supplementation strategies to increase energy availability during the event. Cutting weight: Carbohydrate depletion, creatine cessation, and water loading are three strategies the authors discuss. Switching to a very low carbohydrate diet during the last few days of competition can help deplete total muscle glycogen stores. 1 g of carbohydrate binding to 3 g of water when stored in the muscle can be an effective strategy. A brilliant manuscript outlining acute weight loss strategies is provided below.

James’ Comments “For practitioners working with strength and power athletes, this paper provides a great starting framework to now work your own nutritional strategies from. Another resource would be the podcast below by Sophie Killer discussing fuelling track and field athletes. I say your own strategies because, as an example, and referring to the table above, I have rarely seen any athlete that I personally work with consume 6-7 g.kg.body mass-1 of carbohydrates on a training day that has no change in training volume. Although this maybe the target, it is simply very hard to physically implement this amount of food for the athlete, especially when they are maybe living on their own and having to cook for themselves. As an example, a 75 kg athlete who needs to consume 7 g.kg.body mass-1 would require 525 g of carbs that day, that’s almost the same as 11 jacket potato’s on top of protein, vegetables, and fluids! This is where the use of solids, liquids, and gels maybe required instead of just food on its own. With this in mind, know the targets that need to be hit, but understand that they may not always be possible especially for a travelling athlete and work with the individual athlete to see what is possible for their lifestyle. The importance of working on an individual basis is outlined below in the video.”

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