Wisdom Wednesday: Intracoastal Waterway Century

On October 25, 2015, my wife, Margie and I participated in the Spacecoast Freewheelers metric century bike ride. The ride began in the historic little village of Cocoa, wound north and east along the Indian River. The first rest stop was the American Police Hall of Fame Museum. After passing through the Kennedy Space Center, the course then turned south along the east side of the Indian River and Intracoastal Waterway. At southern most point, the route crosses the Indian River again, turning north back to Cocoa.

The weather was mixed with cloud cover to keep the heat down but the wind shifted as the ride progressed so we faced a head wind for the first 55 miles. Once we made the final turn to go north, the wind decided to stay southeast and give us a little push.

Neither of us had any experience in drafting as our annual trek from Miami to Key West strictly prohibits riding any closer than one bike length between riders. Triathlons also will disqualify riders for drafting.

However, after Margie and I each spent close to 40 miles without drafting, we were exhausted. Finally, a couple of retired firemen from Jacksonville offered to lead us in as they had been drafting us since the first rest stop.

Apparently, people who draft and never lead are called “leeches” and we had between 10 and 20 at all times. They ride in the draft that you create, saving up to a third of the energy the lead rider is expending.

When It Comes to Jogging, Easy Does It

“In this study, the dose of running that was most favorable for reducing mortality was jogging 1 to 2.4 hours per week, with no more than three running days per week,” said study researcher Jacob Marott of the Frederiksberg Hospital in Copenhagen, Denmark. The best pace was slow or average – about 5 miles per hour, he added.

Out of a pool of about 5,000 Danish adults, Marott and his colleagues followed nearly 1,100 healthy joggers and 413 sedentary people for more than 12 years. The joggers noted their hours and frequency of jogging, and their perception of their pace.

The strenuous joggers, the investigators found, were as likely to die during that time period as the sedentary non-joggers. Light joggers and moderate joggers fared better, in that order.

The findings were released online Feb. 2 in advance of publication in the Feb. 10 edition of the Journal of the American College of Cardiology.

What is it about strenuous running that might be harmful? “We believe that long-term strenuous endurance exercise may induce pathological structural remodeling of the heart and large arteries,” Marott said.

However, a U.S.-based researcher said the debate about the optimal dose of running for longevity is far from resolved.

The new study has limitations, said D.C. Lee, an assistant professor of kinesiology at Iowa State University, who co-authored an editorial accompanying the study.

Exercise as the Best Medicine

Sports cardiology researchers from Texas Presbyterian Hospital recently published their new study in the journal Circulation.

They wanted to demonstrate that cardiac adaptation to regular exercise is based on the training load, not just genetics. They enrolled 12 sedentary human volunteers in a 1-year training program. All participants underwent supervised training, frequent MRI scans, and even cardiac catheterization at the beginning and end of the study.

The endurance training began with exercising 30 to 45 minutes three to four times per week by brisk walking, jogging, swimming, or cycling. Then, after a couple of months of base training, exercise intensity and duration was gradually increased. After 9 months, a long run was added to a steady dose of interval training. At the end of the study, average exercise time per week was 7 to 9 hours.

The results were striking. The right and left ventricles of all participants underwent structural changes seen in elite-level athletes. RV mass and volume increased significantly and immediately. Months later, when more intense intervals were introduced, the researchers observed the same eccentric hypertrophy in the LV. VO2max surged by an average of 20%. Cardiac compliance, diastolic volume at a given pressure, increased significantly – but nowhere near as much as elite athletes.

At the end of the study, all the previously sedentary subjects completed their endurance goals: a marathon for 10 of them, an Olympic-distance triathlon for one and a cycling “century” (100 miles) for one.