There is much concern from endurance athletes about keeping fit and well trained during the extended holiday season. Athletes tend to get caught up in the "have to train a lot" mentality and as a result, stress themselves and their families about training, training, training.

You don't have to go bonkers when you're on vacation! This is the time of year to relax a little bit and enjoy some time with friends and family.

The truth about detraining is that it takes quite a bit of inactivity to lose all the gains you've made over a long season (or seasons) of regular and consistent endurance training.

The first thing to go is your top-end speed. If you keep up with a few workouts per week but don't do consistent speedwork for a few weeks, you might lose 5 to 10% of your 5k or sprint triathlon speed. That would be 1 or 2 minutes over a 20 minute 5k race.

While that is certainly a lot from a competitive standpoint, remember it takes several weeks to lose that ability, not just one week of vacation.

Your endurance takes even longer to lose. Let's say you miss two or three entire weeks of all exercise. Your ability to go out and do a long ride or a long run would only diminish by a few percentage points.

The key here for both top end speed and endurance is to keep up with a few (3 to 5) workouts per week during the holidays.

For pure runners, this could be 2 x 30 minute runs and 1 x 45 minute to 1 hour run. Simple for most of us to complete. If you add another run or include some strides (20-30 second accelerations to 'fast' pace) in here, even better.

For triathletes, if you can keep up with a couple of runs, 1 or 2 short rides, and 1 swim, you will return in January ready to start knocking out the miles with little effect to your overall fitness.

Of course, running is the easiest aerobic exercise for most of us to do, and requires the least amount of additional time and effort to complete. So if you want to just run for a few weeks, and accept some performance loss in swimming and biking, you can just focus more on those when you return to a regular schedule.

You also don't have to hit the gym for extended strength training to keep up with your core fitness. A handful of simple exercises like situps, pushups, planks, and bodyweight only squats once or twice a week will keep a lot of your stabilizing muscle groups in shape for the next season.

Remember, you have all of next year to get ready for your 2010 goals. So enjoy some time with your family and learn to relax.

Marty Gaal is a NSCA certified strength and conditioning specialist (CSCS) and USA Triathlon coach.