Races are plentiful this time of the year. With distances from one to 26.2 miles, runners can race as often and as long as they like if they follow a few simple rules.

With so many choices, it's easy to get caught up in the racing cycle. Racing can be rewarding in itself and can be a great training tool as the hard runs build strength and improve the cardiovascular system. Racing also builds confidence and a sense of pace.

But the downside is that too much racing can overtax the body, inviting injury or illness. It also can overload the mind, leading to mental fatigue and staleness.

Follow the following rules to keep those negatives at bay:

The 10-percent rule:

Never increase mileage or speed by more than 10 percent per week or 10 percent per month.

It's easy to add a weekend 5K to the training schedule just for fun. But don't forget to log the distance and speed into your training journal.

If you add a race to your schedule, cut down or cut out one of your other hard workouts.

Increasing speed and distance too fast puts a strain on muscles and connective tissues. While micro-tears in muscles heal in a few days, damage to tendons and ligaments takes longer because those tissues have less blood flow. You need more rest to heal and to let training take effect.

Remember to run easy or rest on the day before and the day after racing, just like you would on hard training days, to prevent overtraining.

The second 10-percent rule:

Never race more than 10 percent of your total mileage per week.

When I trained for the 2002 Presque Isle Marathon, I ran 5Ks nearly every weekend throughout the summer as hard training runs. That worked because during marathon training my mileage averaged more than 50 miles a week.

Racing more than 10 percent of total mileage invites injury because of the added stress on the body.

But racing is hard on the mind as well, causing what David E. Martin called in his book "Better Training for Distance Runners" the "runner's blues."

Nutritional percentage rules:

Carbohydrates have fallen out of favor as a dietary base, but carbs are a runner's basic fuel. It's especially important to maintain a good balance of 60 percent carbohydrates and 25 percent fats while racing to keep the fuel tank filled.

Add 15 percent of the diet as protein to rebuild and repair the body.

Be sure to replace fluids lost in racing. Drink plenty of electrolyte-rich sports drinks, as well as vitamin- and mineral-rich juices, to keep muscles and nerves firing.

The rule of the Runner's Triangle:

Overstressed runners sometimes dream of a life of nothing but training and racing. But that life would quickly become a nightmare.

The Runner's Triangle, as explained in Bob Glover and Pete Schuder's "Competitive Runner's Handbook," includes running, work and family and friends. Life is a balance between the joys and stresses of each.

While racing can be a joy, it also adds stress, not only to the body but also in other areas of a runner's life.

Weekend races can interfere with family time. And hard racing on weekends can leave you drained at work on Monday.

Remember to take a reality check once in a while to keep racing and life in balance.

Saturday, 9 a.m.: Summer Sunrise 10K Run-Walk, Kittanning. 724-545-9622Saturday, 9 a.m.: Pittsylvania Mile Run, Pittsburgh. Run in age groups on the Carnegie Mellon University track. 724-464-2222Sunday, 8:30 a.m.: Monroeville Rotary Charity Classic 10K, Monroeville. Rolling course, refreshments, random-drawing prizes, homemade candy to all pre-registered. Also a 5K at 9:30. 412-823-9000 or grick@ymcaofpittsburgh.orgSunday, 9 a.m.: Greenfield Glide 5K, Schenley Park. Cross country run on park roads and trails. 412-422-8885 or 412-422-7800Sunday, 6:30 p.m.: No-Problem Run 10K-2 Miles-1 Mile, Pittsburgh. Run through Schenley Park, part of Greater Pittsburgh Road Runners series. 412-242-5746 or 412-247-7450June 9, 7 p.m.: Strawberry Days 5K, Grove City. First run in Mercer County Twilight QUAD. 724-458-4435June 10, 7 p.m.: Highlands Hospital 5K Run and Walk, Connellsville. 724-626-2440June 10, 7 p.m.: Sandy Lake 5K, Sandy Lake. 724-376-3650

Economy 5K, May 8: Mark Courtney, 2nd Overall M, 18:28; Lee Anne Beiber, 1st Overall W, 22:15; John Neff, 2nd 25-29 M, 19:22; Sean Moore, 3rd 25-29 M, 23:30; Bruce Hall, 3rd 30-34 M, 25:18; Tom Propst, 3rd 50-54 M, 26:46; Tim Davison, 2nd 35-39 M, 26:56; Frank Bischak, 3rd 35-39 M, 27:45; John Banks, 3rd 55-59 M, 30:07; Bob Pudlo, 23:35; Bruce Faller, 23:53; Ron Hartle, 25:04; Doug Shymoniak, 27:56; Len Yensull, 30:10; Allan Berenbrok, 32:53May Day 5K, May 22: Mark Courtney, 2nd Overall M, 38:53Send comments and suggestions to: 435 Cherry Valley Road, Saxonburg, PA 16056. Phone or fax: 724-352-4395. Email: lotzak@highstream.netPat Neubert is the running columnist for the Butler Eagle.