For me I gotta have both breakfast AND Lunch to get a decent workout, sometimes I can get away with strength training on only Breakfast but I won't have enough energy for Cardio.
Also on average I sleep 12 hours a day and have trouble getting out of bed in hot, humid weather. Today I didn't get out of bed until 1PM, ate lunch, went to the gym, strength training went well but I struggled with Cardio
Wanted to run a mile in 10 minutes but got tired around the 4 or 5 minute mark and did incline for the other 5 minutes. Wanted to do least 5 minutes on the stair stepper but got tired around 3 minutes
it bums me when I struggle with cardio I generally feel better when Cardio goes well and I meet my goals for that particular gym session.