The way I usually set up training plans especially this time of year is very similar, 1-2x a week for swim, bike, run activities. I also add in a day or two in the gym working on strength not much mainly 3 sets of 5 reps of various workouts with about 75-80% of 1 rep max worth of weights. Focusing on building power, most triathletes and endurance athletes in general do not need to work on endurance in the gym we get enough of that in our sport. If we focus on strength/power in the gym we will be a little better equipped for the season ahead. Also make sure you are having enough rest between workouts, trying not to do two days in a row in the same sport is usually what I try to do.