一人で練習する際、足腰の筋トレの一環として、交互の蹴りや諸蹴りをやっている。
交互の蹴りはしゃがんだ状態から立ち上がりつつ前蹴りなり横蹴りを左右交互に行う。スクワットとその場蹴りを同時にやるようなものである。
諸蹴りはしゃがんだ状態から飛び上がり、両足で閉塞での前蹴りや、開脚での蹴りを行う、スクワット＋ジャンプの筋トレである。
学生時代はどちらも結構得意で、数十回、百回以上でもやっていた。現在は各10回だけだけど結構良い運動になる。特に諸蹴りは、飛び上がって着地したときの衝撃が、脊椎に適度な刺激を与えられ、全身の骨粗鬆症防止等にも効果があるだろうと思い、土日の自主トレ時に取り入れていた。
最近、諸蹴りの後の着地時に結構衝撃を受けるな、とは思っていたが膝を痛めてしまった。諸蹴り以外に心当たりが無い。学生時代は何とも無かったが歳で着地方法がおかしくなってしまったのか、或いは若い頃にやり過ぎたのか・・。
空手は全身運動で体育としても優れたものだと思っているが、学生時代にとても激しい稽古をした人が歳を経て、運動のやり過ぎによる膝の障害が顕著となったり、循環器系に異常（心肥大に伴う）が出たりしている。ネット検索すると、オーバトレーニングと言って結構常識になりつつあるようである。空手をやって体を壊す、ということは空手普及の目的にも反しており、あってはならないことだと思っている。但し、これは何十年も経たないと自覚症状が出ないので、若い人には言っても多分判らないだろう。歳を取ってから後悔することのない最適な運動量、今の時代、科学的に判らないものだろうか・・。
因みに、ネットでは9時間後には回復できる量であること、毎日の激しい運動なら60分以下（30～40分）等の情報は見つけた。
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When practicing alone, I'm doing alternate kicks and both feet kicks as part of the muscle training of the legs and hips.
Alternate kicks are a front kick and a side kick alternately left and right while rising from a crouched state. It's like doing squats and kicking on the spot at the same time.
Both feet Kicks is a squat + jump muscle training that jumps up from a crouched state and performs a front kick with both feet or a kick with open legs.
When I was a student, I was pretty good at both, and I did dozens of times, even more than a hundred times. Currently it's only 10 times each, but it's a pretty good exercise. In particular, I thought that the impact of jumping up and landing would give an appropriate stimulation to the spine and would be effective in preventing osteoporosis of the whole body, so I have done it during the self training on Saturdays and Sundays.
Recently, I have thought I received to shock when landing after both feet kicks, but I hurt my knee. I have no idea about the cause other than both feet kicking. I didn't have anything when I was a student, but at the age of the year, the landing method went wrong, or did I overdo it when I was young?
I think that karate is excellent for physical education as well as whole body exercise, but as people who practiced very hard during their school days became older, knee damage due to overexercise became noticeable, and it became abnormalities (accompanied by cardiac hypertrophy) of a cardiovascular system. When I search the internet, it seems that overtraining is becoming quite common sense. It is against the purpose of popularizing karate to break the body by doing karate, and I think it should not be done. However, this is probably not known to young people, as they will not have any subjective symptoms until decades have passed. The optimal amount of exercise that you will not regret after you get old, is it scientifically unknown in this era?
By the way, I found information of the proper amount of exercise on the internet that it can be recovered after 9 hours, and that it takes less than 60 minutes (30-40 minutes) for daily strenuous exercise.
