This week, we look at the heightened calorie demand pro rugby players experience from playing competitive games.
As you’re highly aware, rugby is a contact based sport where collisions during tackles, breakdown and set piece can result in muscle damage and perceived muscle soreness.
Knowing this, players need to adjust their nutrition intake to meet the elevated recovery demands. Of which, adequate energy availability is of primary concern.
To address this issue, Hudson et al (2020) examined the energy needs of pro rugby players across a competitive training week.
More specifically, they measured changes in resting metabolic rate (RMR) which is a large component of total energy expenditure (TEE) and is essentially the energy expended per day to maintain normal bodily functioning at rest.
To analyse these changes, they measured RMR every day of the week apart from game day. Of which, they found a significant 10% increase in RMR from game day-1 to game day +1 (~231kcal), which then continued to remain elevated until game day+3.
This increase in energy expenditure was mostly attributed to the heightened number of collisions in games, where on average; forwards experienced a greater increase compared to backs.
I.e. forwards are involved in more contact and are therefore likely to have elevated rates of muscle breakdown and a subsequent increase in calories needed to support recovery.
Interestingly, higher running loads (distance and speed) don’t significantly impact RM. Therefore, collision induced muscle damage is most likely the primary cause.
More interestingly, there was large variability within the team, where some players RMR increase by 1,000kcal/day.
Therefore we can’t use a one size fits all approach with our recommendations, as they may not be fit for purpose for every player. Specificity is key.
With this in mind, players should adjust their calorie intake accordingly in the days following a game to support recovery alongside periodising their nutrition based on the training demand of the day.
Given that glycogen replenishment post game is of higher urgency, it’s recommended that the increased calories should be obtained via carbohydrates.