Please bear with me writing the description for this one. I want to include the recipe, citations and links to buy every product so you too can do everything in this video and understand why but it may take a while.

Recipe (for 80g carbs in a 750ml);
Maltodex 46g (25p)
Fructose 34g (27p)
Bcaa 5g (20p)
Salt 0.2-0.5g (1p)
Citric acid 0.2-0.5g (1p)

Total cost 74p per portion

Carb Ratio: O'Brien et al. Med Sci Sports Exerc. 2013 45(9):1814-24. DOI: 10.1249/MSS.0b013e31828e12d4
BCAA in drink : Kim et al. J Exerc Nutrition Biochem. 2013 17(4):169-180 DOI:https://doi.org/10.5717/jenb.2013.17....

The fantastic resource from the Australian Institute of Sport giving all the information you could ever need re: creatine, beta-alanine, sodium bicarb etc. Please read in depth! https://www.ais.gov.au/nutrition/supp...

Links to buy each ingredient (I am in no way affiliated with any brand below):
Maltodextrin: https://peaksupps.co.uk/products/malt...
Fructose: https://peaksupps.co.uk/products/fruc...
BCAAs: https://peaksupps.co.uk/products/flav...
Citric Acid: https://www.buywholefoodsonline.co.uk...
Creatine: https://peaksupps.co.uk/products/crea...
Beta Alanine: https://peaksupps.co.uk/products/beta...
And for completeness;
Sugar: https://www.sainsburys.co.uk/gol-ui/p...
Salt: https://www.sainsburys.co.uk/gol-ui/p...
Sodium Bicarb: https://www.sainsburys.co.uk/gol-ui/p...