Individualized nutrition and periodized diets recommended for rugby league youth

26 Jan 2021 --- Individualizing nutritional plans could help young male rugby league players maximize performance and optimize recovery throughout their careers.

Supplements may also be the “cherry on top” to maximize performance. Researchers from Queensland University of Technology (QUT), Australia, have investigated how nutrient periodization – meaning eating specific foods at specific times – might improve players’ physical capacity during the preparatory and competition phases of a season.

“The diets in our article are examples of how carbohydrate periodization could look as a sample menu,” lead researcher and associate professor Vince Kelly from QUT’s Faculty of Health’s exercise and nutrition sciences tells NutritionInsight.

“Players should fuel for the work required, meaning eat more carbohydrates on more intense training and match days, and eat fewer carbohydrates on relatively easier days, through a nutritious diet,” says Kelly. 

Kelly is a member of the National Rugby League Research Committee and has more than 20 years of elite sport experience.

Personalization is taking off in the nutrition industry, as spotlighted by Innova Market Insights’ third top trend for 2021, “Tailored To Fit.” 

The market researcher notes that personalized nutrition is on the rise, moving within the preventative care arena.

(Image credits: QUT Media)The cherry on top
Professional rugby league is an intense, physically demanding sport and young male players (aged 16-24) have “incredibly high energy requirements.”

“Young players must also eat and drink to facilitate growth and maturation, hence they could possibly have increased nutritional needs compared to [older] professionals,” co-author and PhD researcher Liam Oliver from QUT also shares with NutritionInsight. 

“All players, regardless of age, should aim to meet their individual nutritional requirements in terms of overall energy intake and diet quality, and some supplements could be the ‘cherry on top’ to maximize performance.”

Here, the QUT researchers found that cherry concentrate, for example, taken consistently three days ahead of a match may improve muscle damage recovery. 

Meanwhile, 30 mL taken post-match may aid sleep. Also, blueberries or blackcurrants taken one-hour pre-match could improve sprint performance.

Cherries are rich in antioxidants, which may benefit collision-sport athletes by targeting the secondary inflammatory response from impact-induced muscle damage, reads the study.

What should they eat?
According to the study’s findings, young rugby league players should include 6 to 8 g/kg of carbohydrates, 1.6 to 2.6 g/kg of protein and 0.7 to 2.2 g/kg of fat staples to their daily diets.

For performance nutrition, a nutrient periodization plan recommends:

• 5 g of creatine daily continuously.
• 4 to 6 g of beta-alanine per day four to six weeks before matches.
• 80 to 320 g of carbohydrates, 20 to 30 g of protein, 300 mg polyphenols, 3 to 6 mg of caffeine per kg one to four hours pre-match.
• 80 to 180 g carbohydrates, 20 to 67 g protein up to two hours post-match. 

“Our review discussed how periodized nutrition can be applied in the ‘real world.’ Players who follow these guidelines, along with a structured training program, should see increases in their rugby performance,” says Kelly.

Different field positions, different diets
Kelly highlights that personalizing diets is also relevant for different rugby league field positions. 

“For example, front row forwards typically weigh more and must handle several heavy collisions, so eating more will help them build size and strength, while recovering from the muscle damage experienced from playing matches.” 

Oliver (left) and Kelly’s research recommends rugby league clubs “invest” in young players’ diets to aid performance and recovery.Typically smaller players, such as scrum-halves, have different high energy requirements: 

“[Scrum-halves] need a nutritional plan that will allow them to perform repeated sprints during a match, while making sure they do not carry too much excess body mass,” adds Oliver. 

Nevertheless, two players who play in the same position may have very different genetic makeups. No two players are alike, and neither should their diets be.

“Therefore, every player has different goals even if they have similar playing demands, so it is more important to individualize a diet to the person first and then ensure they are meeting the positional demands,” Oliver explains.

Full season recommendations wanted
Currently, there are no full season nutritional plans. “Studies have investigated pre-match nutrition during an in-season period and monitored players’ pre-season dietary intakes,” Oliver details.

“However, collecting data across an entire season in a full squad is difficult and yet to be completed. More research is needed before robust nutrition recommendations can be made for an entire season.” 

The QUT study advises sports nutritionists and dietitians to synchronize with staff and players to periodize individual nutrition plans and group catering. 

The individualization of nutrition protocols, including efficacious supplements such as creatine, caffeine, beta-alanine and polyphenols, deserves further exploration, states the study. 

“We also hope this paper encourages discussion and subsequently more research that will eventually lead to rugby-specific nutrition recommendations, as well as more research in the women’s game,” Kelly concludes.

By Anni Schleicher