Half-Ironman or 70.3 training is no walk in the park. Physical activity guidelines for healthy living include 30 minutes to 1 hour of moderate aerobic exercise 5 days a week (or a lesser amount of higher intensity), and 2 or more days of strength training.
Half Ironman training, on the other hand, will include at least a couple of days a week in the 2 to 4 hour range of exercise. So participants are vastly exceeding what is needed to be healthy, and moving into specific event physical training.
It's an entirely different animal and one you should be mentally prepared for.
A basic, beginner level plan will likely have athletes build up to a handful of weeks in the 8 to 10 hour of total training time. This sort of approach is for athletes who just want to finish the event. There would be at least 1 ride in the 50-60 mile range and one run in the 10 mile + range. Athletes need to be able to finish these distances in training to ensure they won't fall apart on race day. This would usually be a 5 or 6 day a week plan.
A tougher, intermediate plan will have athletes build to some weeks in the 12 hour total time range. There will likely be 2-3 rides over 50 miles, and several runs in the 10+ mile range. Chances are this is a 6-7 day a week training plan. These plans are for experienced athletes who want to do well but either can't commit more time, or aren't concerned with doing their absolute best.
Advanced plans are going to build athletes into the 12+ hour range. This could be 14 total hours, or it could be 25, depending on how much time and energy athletes can commit to their training. 25 hours in a week is in the pro-athlete range of training. Either way, advanced training is for experienced athletes looking to win their category, qualify for world championships, or win overall. There are usually not a lot of full 'days off.' Recovery days will usually include a mix of swimming, strength training, or yoga.
With all of these plans, consistency throughout the program is critical to success. Each successive week or period is dependent on advancing aerobic endurance, durability, mental toughness, and lactate threshold improvement in the preceding period. You can't willy nilly do some don't some and expect to meet your race day goals. If you've been stuck at 25-30 miles for your long training ride, jumping to 50-60 miles 4 weeks before the race is a) going to hurt and b) could cause injury.
There are times in your life where signing up for this sort of training works, and times when it is overreaching. Healthy fitness training is a habit everyone should get into (but obviously a lot don't). You can definitely pull off 5ks, sprint triathlons, and maybe Olympic distance triathlon with basic structured, week-in and week-out exercise. Advanced athletic training like half or full Ironman training requires balance in other aspects of your life. If you just took on a new job, or have a one year old at home, it's probably not the right time.
Marty Gaal, CSCS, is a USA Triathlon coach who lives in the Triangle area of North Carolina. Marty has been coaching endurance athletes since 2002. You can read more about OSB coaching services at www.osbmultisport.com.
One Step Beyond is the producer of the Powerstroke®: Speed through force and form freestyle technique DVD, intended to help new to intermediate triathlon swimmers become faster and more powerful in the water.