Researchers examined how much exercise was needed to maintain or increase muscle mass, size and strength in adults ages 20 to 35 and ages 60 to 75.

In the 16-week first phase of the study, all the participants did three sets of resistance training exercises (leg press, knee extensions and squats) three times a week. In the 32-week second phase, participants were dividing into three groups: some were assigned to stop resistance training altogether, some were told to reduce training to one day a week, and others were asked to cut down training to one day and one set of resistance exercises (as opposed to three sets) a week.

In the younger adults, muscle size was maintained in both groups that reduced their training. This was not the case in the older adults, whose muscle size shrank even if they did one to three sets of the exercises one day a week.

However, one day of resistance training a week was enough for both younger and older adults to maintain their strength -- at least for an extended period of time.

"We are not advocating that people only train one day a week indefinitely, but we do believe such a program can be effective during temporary periods when it is difficult to maintain a consistent, intensive exercise regimen several days per week," study leader Marcas Bamman, of the University of Alabama at Birmingham, said in a news release from the American College of Sports Medicine.

The study appears this month in the journal Medicine & Science in Sports & Exercise.

"Our data are the first to suggest that older adults require greater weekly maintenance dosing than younger individuals to maintain resistance-training-induced increases in muscle mass," Bamman added.

Bamman said all adults "should include progressive resistance exercise in their weekly regimen, but there will always be times, such as extended travel or a family illness, when exercise is difficult to sustain." In such cases, the study suggested, resistance exercises once a week are certainly better than none.

I typically strength train in the winter and gradually incorporate running in the spring through summer.  This summer, my strength programs have included the Exerbotics Leg Press, Chest Press / Row and various barbell exercises twice a week.  Running programs have been a combination of long runs (up to 5.5 miles), interval training and speed runs (usually one of each per week). 

Scenario: On July 23rd while on a 4 mile tempo run, my right hamstring was unusually sore.  I experienced some soreness and tightness for the next 24 hours. 

July 25th: (A beautiful day), I began a cautious run with plenty of warm-up.  During a moderate first mile, the right hamstring was still tight and sore.  At about 7 minutes into the run, I was loosening up and able to get into a better rhythm.  While gaining speed, I felt the dreaded hamstring "grab"; the same feeling you get when you are about to significantly pull a muscle.  The run was instantly over with significant pain and discomfort.  It obviously was not a sever pull but concerning none-the-less. 

Strong discomfort was present with the hamstring for several days. 

July 26th: No Training

July 27th: Moderate strength training day, primarily upper body and lower body range of motion with light free weight loads. 

July 28th: No Training

July 29th:  Soreness and tightness have significantly diminished.  Strength training day to test strength loss in the leg.  

Training Conditions:

Singe Leg Leg Press

6 Repetitions per Leg (First set displayed only)

Intensity: 85% of Max Effort

Results (Compared to Exerbotics strength training on July 14th):

Illustrated in the chart below, contrary to a muscle injury, all meaningful statistical categories showed an improvement from July 14th (pre-injury) to July 29th (4 days post-injury). 

Given the pain, soreness and stiffness, why were the strength results IMPROVED from a pre-injury training session? 

Hypothesis:

I questioned the likelihood of a hamstring pull during a moderate distance run and theorized that this might be a symptom of the true problem (nerve or back related?).  Having been a victim of sever hamstring pulls in the past, I knew that any muscle damage would result in some degree of strength loss. 

Although a post-injury Max test was not performed, I attribute the training improvements to a combination of the following:

• ·        Both legs improved in performance.  The Leg Press was performed as the first exercise on July 29th and, although not documented, the July 14th set was most likely completed in the middle of a strength training session.
• ·        The July 29th training session followed 4 days of lower body rest.  The July 14th training session followed a high intensity running day.
• ·        The muscle did not see any major fiber damage leading to the probable conclusion that the source of the problem is elsewhere. 

Conclusion:

Proceed training with caution.  Full release for strength training with monitored running while increasing volume and speed based on soreness.