title: Keras: update model with a bigger training set
body: <p>I trained a model with Keras for text classification (supervised learning) using a training set. Let's say that there are 50.000 sentences in this training set.</p>
  
  <p>During a week I collect 5.000 new sentences and I add them to the old training set.</p>
  
  <p>If next week I want to train a new model with the new and bigger training set (50.000 old sentences + 5.000 new sentences), should I restart the training phase from the beginning, or can I take the old model and "update" it in some way to save some time? </p>