AFL players - STOP training this way!
Regardless of your sport, strength training will increase your strength, muscular endurance, core strength ect. - but did you ever think you could be training in a way that will DECREASE your speed? Or not be effective for your sport?
Lets take AFL for an example; the key performance indicators (KPI'S) for AFL would be speed, power, strength (arguably max strength), endurance, stability... the list goes on! But how often do you see local level players complete a "bodybuilder type" program? I challenge you to look next time you're in the gym!
Now for those who don't know what this looks like, let me explain - it's main characteristics are lifting moderate to heavy weights, high volume (sets x reps) with little rest or to volitional failure (you can't left the weight anymore). Now let me explain why this isn't necessarily the most beneficial method...
1. It can make you too heavy. Now this may sound weird - don't you need muscle to be strong? Yes. But, too much muscle built can make you slow (poor power : weight ratio). Which leads me to point 2.
2. It can make you slow. Lifting weights like a bodybuilder (slow, repetitively) has been shown to alter a muscle's contractility - which means it may contract slower. This, in a sport where speed is a KPI isn't an especially great outcome. Lifting weights with intent or velocity (https://www.scienceforsport.com/velocity-based-training) greatly increases your muscles ability to contract faster.
3. You get/stay tired for longer. This method of training has a high volume load, which places your body under immense pressure and doesn't allow sufficient rest/recovery time. Now volume load is important in sports of a high speed/movement nature (AFL, Netball, Volleyball, Tennis, Hockey etc.) because it denotes the amount of load you are placing your body under at any given time. More load = more fatigue = greater risk of injury.
If we were to do a bodybuilding program for squats - 4 sets of 10 reps at a weight of 100kg, that equals 4 tonnes of weight lifted - compared to a more velocity/power based (remember, important for speed) of 5 sets of 4 reps at a weight of 120kg equals 2.4 tonnes of weight. The volume load of the latter is less VOLUME than the first, which means LESS FATIGUE/MORE POWER and SPEED.
So concluding, if your sport demands speed, power, agility - train those aspects with intent and in the same manor your sport demands them!