A training program/weekly routine to build endurance

Sunday - Long Run (12 miles) or Long Bike Ride (25 miles)
Monday - Cardio training stationary bike (30 minutes) followed by core and strength exercises (30 minutes)
Tuesday - Stroke and Stride (Swimming for 80 laps on a 25 meters pool) & running 3.1 miles
Wednesday - Rowing for 30 minutes and strength training (30 minutes)
Thursday - HIIT/Running intervals (400 meters) - 16 repetitions rest of 1 minute between reps
Friday - Spinning for 30 minutes (with resistance) and reactive/plyometrics training for 30 minutes
Saturday - Swim for 1500 meters