I have been on a good training stretch for the last 6 weeks doing around 8-10km running per day and 20-30km XC skiing while we are on lockdown and I can't swim. Most weeks have been 18-20 hrs of training so general fitness is excellent. My runs around XC skiing have been good quality, either a run on fresh legs before skiing mid day or an evening run on treadmill after having several hrs of recovery.

Yesterday was first day back in the pool after lockdown lifted. Before that I was swimming 20-30km per week and running around 70-80km balancing both quite well on 100/100. The first swim was nothing special. Just easy 2700m doing all 4 strokes and some legs only and a bunch of dolphin kicking off the walls and some fin kicking on back. It was all quite easy for first day back in as I wanted to be careful for shoulders and since core and legs were strong from run and XC skiing I did not expect for this to take much out of me.

During my evening treadmill run, everything felt off. Beside the energy side which was not a problem, my quads and hip flexors felt dead and my hamstrings had nothing at all! It just reminded me how much we underestimate the fatigue from the swim in triathlons. Everyone points to bad runs being causes by overbiking, but this was a great reminder for me about how much swimming also subtracts from the run (and bike)