Athletes and coaches utilise a tool called periodisation to work on the different qualities. In essence they break the training period: a few months, a year or even, say, four years for an Olympic athlete, down into periods of time where they will work on different factors important for their sport. The idea is to work on a certain range of qualities. For example, strength and power, whilst maintaining others that might not complement that training, such as cardiovascular endurance.
This periodisation really entails increasing the volume and/or frequency that you train a certain set of target qualities, whilst decreasing the time you spend on the other, possibly interfering qualities. To use the above example:
Strength phase
Per fortnight:
5-7 strength and power sessions,
6 skills,
1-2 endurance sessions
Endurance phase
Per fortnight:
2-3 strength and power sessions,
6 skills,
4-8 endurance sessions
Of course, there are different training cycles with a microcyle being a few days, a mesocycle being from week(s) to a few months, and macrocycle being the longest time considered. A yearly training cycle for a competitive athlete may look like this:
January Endurance, skills
February Endurance flexibility
March Strength, skills
April Strength & power, flexibility,
May Strength, skills
June Competition*
July Competition*
August Competition*
September Competition*
October Competition*
November Competition*
December Rest and recovery
*During the competition phase, skills based and recovery work comes to the fore.