As a skinny guy on an HV plan (188cm at 72kg) I would recommend looking at nutrition. My wife gets on to me when I’m slacking on nutrition because even a few days of underfueling during hard training and I start to get a bit on the gaunt side…
You definitely want to be topped off on calories for the demands of SS work, especially the longer workouts. I’ve got Tallac +4 tomorrow and I’ll be at least having a cup of coffee and toast and jam before I get rolling plus some sweets in my pocket in case I need a pick me up mid workout.
I think chad mentioned eating toast and jam on the trainer during warm up as being his favored method. Simple carbs are your friend.