If you are like me when you exercise, you sweat, a lot! Rehydration is important if you are in typical training mode, but this is critical in multi-event situations (ie triathalons, duathalons or races where there are more than one event on the same day). In these situations, the second performance can be significantly impacted by the water loss during the previous event.
The key is not the quantity of rehydration fluid you take in between events but if the water is retained. A recent paper published by James Lewis and coworkers in the British Journal of Nutrition indicates what is important is to have the correct balance of ingredients. They found that if the number of calories is the same between beverages that the beverage that contained milk proteins provided better retention of fluid and thus rehydration was more effective than carbohydrate-based alternatives ("gram for gram milk protein is more effective at augmenting fluid retention than carbohydrates”).
So what is the magic formula?
According to this study they used a formula for a 750 ml (24 oz) water bottle of
30g carbohydrate (in this study 25.1g glucose(dextrose) and 3.75g maltodextrin)
0.3g sodium chloride (table salt)
0.2g potassium chloride (light salt)
0.6g fat(from the milk protein)
How can you get this formula easily?
¾ scoop of your favourite DynaWhey protein
1 ½ tablespoons of honey (a great source of carbs and some micro nutrients)
A pinch of table salt and salt light (to help replace electrolytes lost in your sweat)
If you use juices, be aware that most juices contain a significant amount of sugar, typically 10 to 12 %. This may swamp out the effect of the protein. Therefore we recommend using a measured amount of sugar or honey to ensure you get the right ratio of protein to carbohydrates.
How much should you drink after exercise?
The paper indicates that 1.5 times your body weight loss. It can reasonably be assumed the weight loss during exercise is fluid loss due to sweat.
There are other papers that indicate that post exercise protein is also important for a number of other reasons such as protein rebuilding, and energy metabolism. Whey protein is a great source of full spectrum amino acids, such as the branched chain amino acids, leucine, isoleucine and valine. Work by a research group at Loughborough including Dr. Susan Sherrifs indicate that drinking beverages that include milk work equal to or better than a commercial carbohydrate sports drinks for athletic performance.
So get out there and have fun sweating, but rehydrate with the right solution. Visit www.iwindirect.com for all of your protein needs.
James, L.J. et al., 2010. Effect of milk protein addition to a carbohydrate-electrolyte rehydration solution ingested after exercise in the heat. British Journal of Nutrition. 10.1017/S0007114510003545.