Putting ourselves through this variability builds our capacity, much in the same way that a long distance runner may do hill sprints to work on their overall fitness.
He has put to one side his business sourcing luxury cars for clients (cars being another passion with which rugby had always had to jostle); he took no holiday over the summer and paid Margot Wells, wife of the former Olympic 100-metres champion Allan and a renowned sprint coach, to work him into the ground in a concerted effort to break into the England team and make the World Cup.
At lunchtime, you rush to the dreaded mall for a 45-minute shopping sprint, then back to work.
If it weren't so tiring, it would be more practical for Chandler just to work on sprinting from the top of the key, catching the ball above the rim and slamming it through the net.
If you are able to work in sprints or iterations, you will be able to break down large projects and deliver them quickly, gaining feedback at each iteration.
He also plans to race in Lucerne, Switzerland, on July 16, and will run a 200-meter race in Lignano, Italy, on July 13 "for fun," he said, to work on his sprinting.
The track, built in 2001, features wheeled sleds running on rails, and allows athletes to work on their sprint starts all year round.
Injuries upset the rest of 2003 for Gay, and his coach Brauman moved on to work as the sprint coach at the University of Arkansas.
Another technique I couldn't manage without comes from the writer and consultant Tony Schwartz: use a timer to work in 90-minute "sprints", interspersed with signficant breaks.
"I'm hoping to race on the Europa Cup or America's Cup circuit next season so I have to work hard, keep my sprint times coming down and weight going up then prove myself to the people I need to impress in order to get selected".
Sprints work best because they push you and force you to work hard in a short space of time.
