A couple of words from my personal experience. When I was attending high school and college in Russia I used to do track and field. My results were pretty good for a non-professional college level: 100 meter sprint – 11.5 seconds, the long jump – 7.1 meters. I trained four times a week for two hours, for a total of 8 hours a week. I need to add that during most weekends, I was playing soccer in the summer and skiing in the winter. So I trained for about 12 hours a week. I have never had injures and I am very thankful for all my track and field coaches.
Most sports scientists recommend that junior tennis players train for no more than 15 hours a week until 16 years old. My kid, between the ages of 8 and 12, played tennis for no more than 6-8 hours a week plus 2 hours of special fitness training. He was a top 10 player in Belarus.
Now see what modern sport tennis specialists advise. A common recommendation from International Tennis Federation (ITF) for junior tennis players:
- For 6-8 years olds: 3-4 sessions a week, each session no longer than 45 minutes. Group lessons, practice on mini court. 50% tennis – 50% other sports. Soccer, handball, basketball, swimming, etc.
- For 9-11 years olds: 1 hour, 3-4 times a week. 70% tennis – 30% other sport.
- For 12-14 years olds: 2-3 hours a day, 4-5 times a week of group lessons. 85% tennis – 15% other sport.
- For 15-16 year old (intermediate level): 3-4 hours of training a day, 4-5 times a week.
- For 16-18 year old (advanced level): 3-4 hours a day, 5-6 times a week.
Approximate number of tournaments per year (singles & doubles): for intermediate players: 15 – 20, for advanced players: 20 – 25. Rest for 1 – 2 days after each tournament.
The problem of some tennis parents and coaches is that they have never read any sports science recommendations. My personal opinion is if a junior tennis player has talent, then 15 hours a week tennis training + fitness and tournaments is more than enough for his development.