Hello! I am a former club racer/triathlete who has taken some time away from training to spend more time with my kids. I have raced as a cat 4 and done a few triathlons. At my best, I weighed 148 pounds and could ride 26 mph for 10-15 min intervals. Nothing outrageous, I know. But now I am 180 lbs and go for 60-90 miin rides averaging 17 mph on flat roads. I am planning to do a couple of triathlons next summer. Should I spend time this winter doing "long slow distance" on the indoor trainer or I would I be better off adding some higher intensity from the start? Thanks for your feedback and help!