If you are unfamiliar with the proper performance of these exercises, be sure to consult with a certified strength training instructor or study a strength training textbook. Also, if you choose to use free weights, keep in mind that dumbbells offer more versatility and less injury risk than barbells.

You may perform the basic workout 2 or 3 days per week, depending upon personal preference. Studies on strength training frequency show that 2 sessions per week are about 88 percent as effective as 3 sessions per week.

Once you have mastered the basic workout, you may add a few more specialized exercises to further impact your triathlon performance. For example, I recommend the 4-way neck machine to strengthen one of the most important and most vulnerable muscle groups in the body. A stronger neck should help both your swimming and cycling performance, and certainly won't hurt your running ability.

Another consideration is the oblique muscle on each side of the midsection that are used extensively in the turning action of the freestyle stroke. My choice for conditioning the internal and external oblique muscles is the rotary torso machine or twisting trunk curls.

Because the triceps are used dynamically in swimming and statically in cycling, it may be advisable to give these muscles a little extra attention. Bar dips target the triceps muscles, and also allow you to master a bodyweight exercise. As you become stronger you can add external resistance for additional strengthening. Just be sure not to dip too deeply, as this may unduly stress the shoulder joints.

Finally, as the legs are heavily involved in all three events, it is important to increase their functional strength as safely as possible. My preference for working the quadriceps, hamstrings, and gluteal muscles together is a well-designed leg press machine which may be substituted for leg extensions and leg curls. One good set of properly-performed leg presses provides all the stimulus you need for stronger leg muscles, without compromising your low back in the process.

Summary
Properly-performed strength training improves overall muscle strength, which increases performance power and decreases injury potential. It is therefore advisable for triathletes to include sensible strength exercise in their training program. However, to conserve time and energy for triathlon training, the strength workouts should be relatively brief and infrequent. Research indicates that performing 8 to 12 basic exercises for one set of 12 to 16 repetitions twice a week is highly effective for balanced muscular development and strength enhancement. Regular but reasonable strength training is my recommendation for a safer and more successful triathlon career.

Wayne L. Westcott, Ph.D., is fitness research director at the South Shore YMCA in Quincy, MA., and author of 14 strength training books.