Hi Climbgoon,
Thanks for your question. A 3:1 recovery powder refers to 3 parts carbohydrate to 1 part protein as a result of recommendations from several research papers that looked into the optimal nutrition strategy for recovery post exercise to help achieve both strength gains and muscle mass gains and replenish carbohydrate stores.
Taking this drink whilst on an expedition will potentially be playing a different role as to taking this drink after a training session back home. Firstly I would recommend the higher in calorie one you can get the better, muscle mass loss during an expedition can be as a result in one or several of these; insufficient calorie intake, less active than when training and more sitting around acclimatising, plus also reduced protein intakes.
The timing of when you propose to take this drink is good at two different time points ensuring protein intake is spread thus further supporting muscle mass recovery/attenuating muscle mass loss.
Drinks choices are quite individual and depend on the taste and your preference. Trial different brands such as Gu, power bar, myprotein, optimum nutrition, hammer nutrition, high 5, Maxi muscle (these are more of the well known brands, others may have some good suggestions of good brands within your location). Perhaps test them out before you go and during one of your big days out, taste preferences change during physical exertion.
Hope that answers your question?
Rebecca Uphill Athlete Dietitian
