By the time you feel like you need the recovery week, you're usually already overtrained.....or hurt. If you feel like you're nowhere close to being overtrained and that you need the extra training you won't ruin your training plan, but the recovery is there for a reason. Training tears your body down, and recovery lets it build back stronger. Recovery is ESSENTIAL to good training, but it only works if there is something to recover from. Use your discretion, but err on the conservative side. What will that extra tempo run do? It will either take 5 seconds off your next race or put you out of commission for a month and add 5 minutes. Your body should tell you what to do.

You'd love my training, every week's a recovery week.

Mark.

as UFTriGator said you need to have something to recover from, that said, my recovery weeks have the usual ammount of sessions but they are optional. i also get up at 6am to train lighly not 4am. i only do water running during the recovery week, no impact stuff lets the joints recover. cycling i stay on the flat and keep my HR in E1 about 145-150bpm. and swimming i only do drills or 1K main sets.

I have to admit I'm terrible about recovery weeks. The only time I really rest is when sick, really tired, or a few days before a race. I know, too little, too late.

For the occasional major event like a target race, I'll add more rest days in the schedule, but never a true recovery week.

I like how I feel after hard workouts, so it's an addiction.