Time is one of the most limiting factors most triathletes face, but you should try to incorporate at least one strength training session into your training plan each week. Be focused when you are in the gym; each session shouldn't take longer than 45 minutes max--including a quick warm up and cool down.
Strength training can help reduce muscle imbalances from repeating the same daily training patterns. You don't need a complicated program--use compound exercises that engage and build the strength of big muscle groups. The secondary exercises will work your core.
Dumbbell Back Rows1 of 8
Start with your right hand and knee on your bench. Use your left arm and raise the dumbbell in a rowing motion until your elbow is just past the level of your torso. Pause and return to the starting position.
5 to 8 reps, 3 to 4 sets
Single-Leg Deadlifts2 of 8
Hold a pair of dumbbells or kettlebells in front of your legs. Pull your shoulder back and down, and be sure to hold your back in extension throughout the exercise. Lower the dumbbells toward the floor by hinging over at your hips with your right knee slightly bent. Your left leg will rise behind you, and keep your eyes focused on the horizon throughout the movement. Do all the reps on your right leg and then switch to your left leg.
4 to 6 reps for each leg, 3 sets
Shoulder Press3 of 8
Grab a pair of dumbbells and hold them right above your shoulders. Squeeze your abs and legs and press the dumbbells upward in a vertical line until your elbows lock out. Return to the starting position and repeat.
4 to 6 reps, 3 sets
Dumbbell/Kettlebell Squats4 of 8
Grab a pair of dumbbells and hold them on your shoulders. Place your feet shoulder-width apart with your toes pointed out 30 degrees and push your butt back and down. Push your knees out as far as you can and keep them out throughout the entire exercise. Squat down so your hip crease is just below your knees, and as you return to the starting position, drive your hips up toward the ceiling. Be sure to keep your head neutral and look straight ahead.
5 to 8 reps, 3 sets
Push-ups5 of 8
Place your hands on the ground slightly wider than shoulder-width apart and enter the push-up position. While keeping your body in a straight line, bend your elbows out to the sides and lower your chest toward the floor. Return to the starting position and repeat.
4 to 15 reps, 3 to 4 sets
Side Plank6 of 8
Lie on your side, place your feet together and raise your body off of the floor. You can use your forearms or hands depending on your strength, but make sure your body is in a straight line and hold that position. After the timer goes off, switch to the other side and repeat.
10 to 30 seconds, 3 to 5 sets