Originally Posted by
pdlamb
Minor quibble: Agree a single 40 minute ride electrolytes aren't going to cause the problems OP described. However, if he's riding 40-60 minutes every day in hot weather, and especially on a low salt diet, problems might start to surface after a few weeks.
For quick diagnoses, BF or a TV show is a great place to go. If you want an accurate diagnosis, a medical professional is a better bet.
This is not the first time the OP has posted about "extreme fatigue" after short rides and Gatorade always seems to be his solution. For me it would be time to see the doc rather than grasp at straws as to what may be causing this unusual fatigue. Hopefully it will be nothing serious, but he's not going to get a satisfactory answer here.