May I apologize in advance if this subject has been discussed previously. Would a weekly 40 minute tempo ride, a 2 x 20 session and 5 or 6 VO2 max intervals suffice in diminishing a loss of fitness during the winter months? Not all at once ofcourse but on a trainer with each workout a seperate session about an hour total in length. Let's assume that there would not be much more time available for any other lower level workouts in that week. Does the lack of volume at lower levels diminish the benefits of mostly L4 and 5 work?