If it’s a healthy choice and for the sake of performance, do it slowly.
Training is a big enough stress on its own. If you try and also lose weight quickly, the combined stress will probably be too much. Losing training time to illness is never worth it. A more gradual “ramp rate” for fitness (and de-ramp-rate for weight) is more effective in the long-term.
I think of weight in four (decreasing) contexts:
- Lifestyle weight: What I weigh when I’m not training and not caring;
- Training weight: What I weigh when training;
- Race weight: What I get down to before an important event but do not stay at;
- Ego weight: Some kind of fantasy number that hurts performance rather than helps it.
Most people spend too much time thinking about the last two…
For more specific advice, I recommend hiring our nutritionist, Rebecca Dent. (You can connect with her in the second-last section of our Coaches page.) I had Rebecca during my last year of skimo racing, and it was a big help.