Originally Posted by Carbonfiberboy

I use TrainingPeaks for everything. It gives me a heart rate based training stress score (hrTSS) for every activity. Works well for me. Lift skiing is a little weird because it also counts heart beats on the chair. OTOH, HR responds slowly to activity in a conditioned skier so the hrTSS during the DH skiing is probably a good bit low. Seems like it balances out. I get a hrTSS of ~70/hr on the bike and ~40/hr lift skiing.

Training stress is basically about HR which reflects physiologic stress which builds up over time. If one uses a PM on the bike to get a TSS but does many different activities it's harder to get a handle on total training stress. Of course we recover from muscular stress differently than from overall aerobic stress. So sometimes my hrTSS will tell me I'm good to go, but my legs don't have it because I squatted the day before. From gym work, I get a relatively low hrTSS of ~40/hr, about the same as DH skiing or a recovery spin on my rollers. But overall, using a HRM for every activity and then the Dashboard on premium TrainingPeaks gives me a good handle on my fitness and readiness to train.

Of course skiing DH or XC isn't the same training as cycling but who cares? Not I. I train and perform to have fun. It's all fun. My main interest in the training thing is to manage total stress so I get better but don't overcook it and then lose hard-won fitness. And of course cycling doesn't do much for bone strength and for whole body training. Skiing of all sorts is very good for a long and active life, IMO. Skiing helps my riding and vice versa.