Stacey Richardson’s Weekly Workout Tip:
This week’s workout tip is brought to you by the greatest ” S” word in coaching jargon: specificity.
As my athletes and I begin discussing strength-focused workouts and how to make some gains in the off-season, we return to this concept in all our coach-athlete conversations.
“Coach, I could go do 100 push ups!! And I”m great at pull ups!”
Great! Way to go. But for the precious little time that we have to be masters of three sports, to recover, and to build functional strength and economy, is this the answer?
My simple advice is specificity and sport specific work whenever possible. Do the actual sport itself and add resistance if you want to see big gains. For the bike, this is big gear work and hills. For swimming, this is paddle, parachute, and band work. For running, this would be stadiums, hill repeats, harness runs, or (if you ever have one), a sled. Again, do the actual sport and increase the demands on you as you do that sport. Email me for more info or ideas to add to your suffering. 
If you add resistance to say running for instance, would this accentuate any technical deficiencies you may have and increase the risk of injury? Is weight training a safer, more controlled way to build strength? It is a tough one to judge as you say, you will benefit miles more by practicing the sports you are trying to compete in, not to mention save yourself time. Just think it might either enhance a poor technique (if the participant has a poor technique.)