Most triathletes are grown adults with multiple commitments, family duties and time constraints. I have worked with highly motivated world class amateur athletes who have careers and families, as well as beginner or intermediates who do not have nor want competitive goals. Both types of athletes present different challenges.
My experiences have led me to believe that the most realistic training plan for a certain type of athlete is simple and repeatable. This particular approach works for an athlete who is extremely time constrained and highly motivated or is someone who is not as competitively motivated but wants a healthy and realistic training plan.
I call this the "hour-twenty" training plan. It consists of roughly one hour and twenty minute workouts three to five days a week and one longer workout with a day off. In essence, do both weekend workout time slots in one day and take the other day off.
This is a workout that can be completed no matter the time of day, with minimal interference from work or other commitments. There are no double days in this training plan. One and done is the approach.
This training plan is appropriate for sprint to international distance triathletes. It would not be a viable plan for anything longer. If you plan to race 70.3 to IRONMAN, you must make time for longer training sessions.
The key to this type of training plan is that most days will consist of two disciplines. The weekend workout will be the major endurance session of the week. The time allotment for each discipline will vary depending on the strengths and weaknesses of the athlete.
One hour and twenty minutes is enough time to work the various training elements in any training plan—aerobic endurance, anaerobic endurance, lactate threshold, drills and skills and power. It is enough time to burn roughly 700 calories. It is also enough time to burn off life-related stress and spend a little time on yourself.