I'm a doctor, often working 12-hour days and on call some weekends. I rode some centuries last season but was undertrained. How can I get the most benefit out of training a maximum of 10 hours per week? 

I am a new rider primarily interested in fitness. I got my bike in August and began to ride seriously in September, four days a week, about 30 minutes per ride. I average around 90% of max heart rate. I'm totally spent when I get back home. Should I continue to ride this hard to get the most from my training time? 

I just read an interesting study concerning cycling efficiency and power output. The subjects were Spanish pro racers, including former world champion Abraham Olano.  The study concluded that riders in a specific category vary widely in their VO2  max (ability to consume oxygen for energy production). What distinguishes the top riders is greater efficiency. In fact, many top pros with the highest oxygen uptake have the lowest efficiency and vice versa. Any ideas on how to improve efficiency?

Does a person have a finite number of really hard efforts in his athletic career?  I was a competitive swimmer at the age of 10, moved on to weightlifting and then began to ride. Now, in my mid 40s, I find it very difficult to work at the levels that I attained previously. It's like my body just doesn't want to train really hard anymore. The mind is willing but the flesh is definitely not. What do you think?

I was interested in your response to a question about why we get dropped in races or fast group rides. When I'm dropped, I can't chase at a hard pace even after recovering.  In a book I read recently, it said getting dropped when the pace suddenly quickens was attributed to insufficient steady-state riding during the months leading up to competition. But you seem to say that short intervals are a better solution. Which is it?

I'm a mail carrier who walks six miles every day. Also, I'm taking two night classes. I want to start road racing this year, but I come home exhausted and barely have time to study, let alone ride. What do you suggest?

Why isn't cycling offered as an activity in early grades and a sport in high school? I just saw Dr. Kenneth Cooper talking to Congress about obesity in children. The statistics were frightening. What can we do to pass the sport of cycling to the next generation? 

I'm the captain of Team Road Rash, a group of four (three men and me) who are signed up for the Race Across America. We aren't competitive or fast and in fact are just hoping to finish!  Can you help with some training advice since you've ridden the event?

I live in the foothills above Denver (about 7,000 feet elevation), but my job means I travel to sea level for three or four nights each week. I do one or two shorts rides while traveling and don't get a chance to do much training at elevation except on weekends.

With this schedule, I don't feel like I'm getting acclimated for my goal: Colorado's 120-mile Triple Bypass that goes to almost 12,000 feet. What do you think?