I have been doing this trick with balls of all sizes for sometime….a few decades. To try and put more pressure on myself, I allow myself to propel the occasional fruit into the air.  It may not seem like pressure to anyone else, but my wife’s “encouragement” in the background should I have to clean up anything resembling exploded fruit does give me a mini-rush.  Apples are only a small rush because any errors only results in bruising.  It is the cantaloupes, tomatoes, and maybe someday the watermelons that will give me the assurance my heart is still in tip-top shape.