Power Meters / Powermeters (SRM, Powertap, Quarq, Ergomo, Vector, Stages, power2max, P2M, 4iii, InPower, Cinch)

75 miles/5 hours- is a TSS of 350 reasonable? Seems high to me.

http://support.trainingpeaks.com/personal-edition/training-stress-scores.aspx

http://home.trainingpeaks.com/articles/cycling/normalized-power,-intensity-factor,-training-stress-score.aspx

The following scale can be used as an approximate guide:

• Less than 150 - low (recovery generally complete by following day)
  
• 150-300 - medium (some residual fatigue may be present the next day, but gone by 2nd day)
  
• 300-450 - high (some residual fatigue may be present even after 2 days)
  
• Greater than 450 - very high (residual fatigue lasting several days likely)