The most popular time to jet away for miles of smiles is between February and April.
Of course the best time will depend upon your chosen location, but these months represent the most suitable time to log the miles if you're training for summer events in the UK.
If you're looking for a challenge in the Alps, Pyrenees or other mountains though, summer or early autumn are likely to provide better conditions - you may even find that the more famous high passes are still closed until end-May. Autumn weather is often sunny and settled, while summer can see dramatic localised thunderstorms in the mountains.
Being in the southern hemisphere, South Africa's season is the inverse of Europe so it offers spring conditions deep into the northern autumn.