Hi TyroPicard,
No problem .. fly level, and from the pitch attitude and config you can deduce whether your IAS is higher or lower than the recommended value,
If you fly level during an updraft, you will initially observe your pitch attitude is lower than recommended and be tempted to reduce power. If the updraft is large, you will be able to fly level when the aircraft's rate of descent matches the updraft; and if you manage to set your recommended pitch attitude, that's only achievable when you're flying slow.
Thanks vilas, you recognised what I was getting at.