"O Messenger of Allah, I am a man who fasts continually: shoud I fast when traveling?" He said: "Fast if you wish and break you fast if you wish." 'Ata said: "someone who heard him told me that Ibn 'Umar (said) that the Prophet said: 'Whoever fasts every day of his life, and then he has not fasted."  

أَنَّ حَمْزَةَ بْنَ عَمْرٍو الأَسْلَمِيَّ سَأَلَ رَسُولَ اللَّهِ ﷺ فَقَالَ يَا رَسُولَ اللَّهِ إِنِّي رَجُلٌ أَسْرُدُ الصَّوْمَ أَفَأَصُومُ فِي السَّفَرِ قَالَ صُمْ إِنْ شِئْتَ أَوْ أَفْطِرْ إِنْ شِئْتَ