Has anyone figured out exactly why an increase in running distance or endurance causes your chest, arms and tricep muscles to weaken or atrophy in weighlifting, reducing your bench press limits. Now, I am assuming this is true, but I don’t know for a fact, because it happens to me, and I have read cautions about the value of weighlifting here.
There is an interesting article in one of the triathlete magazines this summer about the fellow who was chosen to train for the Hawiaa Ironman. He said he wanted to do triathlons and increase his bench press to 320 pounds. One of the triathlete mentors who was to train him for the ordeal, said, “He’ll be lucky to lift 115 pounds by the time we get through with him.”
Why does this happen?
Here’s what happens to me. I normally do, every two days: 12X135, 10x185, 8x205 on the flat bench, which is not very much. Okay. If I then throw in a 12 to 14 miler on a run, on the days I don’t lift, even if all under 70% MHR, if I go back to the bench press the next day, I can baerely do the 12x135, but that’s about it. My shoulders and chest start wobbling or quivering a bit.
This reduction phenomenon occurs also in bicep curls, and leg presses. Not surprisingly, a day after weightlifiting also causes burn out in the swimming pool, and vice versa. In fact, I have learned not to swim and then go immediately weight lift. Both activities to me reduce the effectiveness of each other. I have almost come to the conclusion that core exercises, whether done with high reps, low weight, or low reps, high weight, either way, and weightlifting in general for the triathlete, is a global impediment to both fitness, speed and endurance. There may be targeted exceptions for this for people with weak quads or backs, which need isolated help.
I can see how core exercises could fatigue a body for swim training, but why running? To me, when we are running, from an upper body perspective, we are swinging our arms and there is energy there, expended in the muscles, but it defies common sense to me how a mere 2 hours of running or so, would eat into your upper physique like that. Is the running eating into muscle, instead of loose fat? Why?