Short recovery and 6 miles easy

Went out with Natasha in the morning for the usual slow 5K. In the afternoon, I tried out a powdered energy drink (SIS PSP22) I bought in Run 4 It and went out for an easy 6 miles or so as I didn't feel up to anything else. The route was basically up Firhill Road, over the hill through Ruchill Park, Bilsland Drive, Balmore Road, along Skirsa Street, down a footpath to Summerston and back down Maryhill Road. On the road past Summerson Asda I felt not quite right and then blew up completely a minute later. I ended up having to walk about half of the way home although after 20 minutes I was able to run the rest of the way. I thought it was most likely that the PSP22 had disagreed with me, so I tried some more in the evening and had the same feeling of indigestion. I'll give it one more try tomorrow, from a different container this time as I think the one I was using has me swallowing a lot of air with the drink.