SPA-FRANCORCHAMPS - McLaren drivers Jenson Button and Lewis Hamilton were happy to get back to less-scary activities as the Formula 1 circus regrouped after its August break.The two World champions have few, if any, qualms about racing through rain and walls of spray or duelling wheel-to-wheel at more than 300km/h but each admitted he was were outside his comfort zone while "relaxing" during the holiday period.TIGHT SQUEEZE FOR BUTTONButton, 2009 champion with Brawn GP, told reporters ahead of the 2012 Belgian GP how a charity triathlon he entered took an unexpected twist. Realising he'd left his wetsuit at his hotel, he borrowed one from his lingerie model girlfriend Jessica Michibata."I decided to try to squeeze into my girlfriend's, which felt OK until I got in the water and it tightened up in certain areas. That was the end of my race because I had a panic attack in the water." Hamilton, 2008 champion, went rock climbing in Colorado and posted pictures on his Twitter feed of a 182m pinnacle he was about to scale.'PSYCHO, ABSOLUTE PSYCHO'"I've retired from climbing," he said. "It just frightened the life out of me. There's not much that frightens me but having to abseil from the top of those mountains was not enjoyable. Not one bit. Going up wasn't the problem until I actually got right to the top."I don't plan on doing it again... the guy who took us went up without a rope. Psycho. Absolute psycho."The August 31 practice sessions at Spa, the long and sweeping circuit that has always been a classic test of a racing driver's mettle with its daunting sweep through Eau Rouge, should be far less unsettling.Hamilton is fourth in the standings, 47 points behind Ferrari's leader Fernando Alonso, after 11 of 20 races. Button is a further 41 behind.Stay with Wheels24 for the 2012 Belgian F1 weekend.