I have been running for almost 2 years now and this year (2012) I am going to do my first 1/2 marathon. A couple of weeks ago, I noticed pain in my upper abdominal muscles on both sides, right about where my diaphragm sits as well as occasional sharp pain in my neck/shoulder, a couple minutes into my run. The pain stops shortly after I stop running but as soon as I start again, the pain returns. I haven't been doing anything differently as far as my workouts go and I haven't been over exerting myself. I do strength training along with running. The pain isn't there when I bike, just when I run. I went from running 4-5 miles at a time to barely being able to run 1 mile because the pain is so intense. Any suggestions? Thanks!
Sunshine you didn't say how far off that Half is, so I will assume by your mileage that it's at least a couple months into the future. If so there could be time to resolve these problems before they negatively affect your training.
This will be a two-part answer because these pains are not likely to be related.
The usual side stitch answer is that the ligaments holding your liver in place get strained by the jostling of running. The usual fix is to take a short break when that pain starts, reach under the right lower rib to adjust the liver upward slightly, and exhale on the left footstrike when you resume. There is less space for the liver to drop when you breathe this way.
However, your case may be complicated by the strength training if it includes core exercises like situps, ab crunches, or leg lifts, because the extra strain on the abs gets further irritated by repetitive strides, since they get their strength from tension in core muscles like the abs. My advice is to relax the strength work as you increase mileage, because this group of muscles will be overworked.
The neck pain is potentially more worrisome, but the good news is that once again, it appears to be more related to impact strain than exertion level. If you can really push it on the bike without the pain, this is most surely the case. If not, time for a checkup!
Somebody needs to observe you running on a treadmill, to see if there are postural reasons for neck and shoulder strain on impact. Remember that many of the shoulder muscles are suspended from the neck vertebrae, and how you hold your arms can unbalance your neck and add more strain than necessary with each footstrike. Many people hold their shoulders too far forward. Try lowering the arms and moving them rearward. Again, some of the strength exercises may have predisposed them to early wear. Replace any current presses with rowing and shrugs instead, to bring the shoulders back. The pecs could be too tight.
It surprises many new runners when after a year or two, aches and pains begin to accumulate. These will inform your style and develop your running form for maximum efficiency down the line. Anybody can train for a little while, but staying consistent over the years usually requires a lot of adjustments along the way. See if you can figure out what other exercises or activities might be adding too much strain, and make changes as necessary.
Meanwhile, some massage to the tight neck muscles, and possibly to relax the abs, might reduce or delay the onset of pain until your recovery catches up with your training. Good luck with your Half!
James has some excellent suggestions. Consider breathing exercises prior to running because the diaphram can contract/spasm based on a number of factors (including the strength of abdominal and lower back muscles). Also, avoid any greasy carbs, sugar or carbonated beverages several hours before exercising. Regarding the pain in your neck/shoulders, consider seeing a good sports chiropractor because running causes continual compression on the spine and it is a good idea to address any potential difficulties early on. Your symptoms are not unusual...runners are prone to joint problems, pinched nerves and so on, so just follow through with the best resources.