Timer Stop

mHandler = new Handler();
    Runnable runnable = new Runnable(){

        @Override
        public void run(){
            while(Running){
                try{
                    Thread.sleep(1000);}
                        catch(InterruptedException e){
                            e.printStackTrace();
                        }
                            mHandler.post(new Runnable(){
                                @Override
                                public void run(){
                                    mtimerinbackground--;
                                    mTimer.setText(String.valueOf(mtimerinbackground));

                                    if(mtimerinbackground == 50){
                                        mtimerinbackground = 60;
                                        mTimer.setText(String.valueOf(mtimerinbackground));
                                        Intent intent = new Intent(PlayScreen.this, Statistics.class);
                                        startActivity(intent);
                                    }
                                }
                            });
                    }
                }
        };
        new Thread(runnable).start();