Sunday, September 19, 2021

Minimum Dose Of Training To Stay Fit

2 months after accident in 2013
I've written about how quickly you can lose your running fitness in the past. With my recent accident, I'm definitely losing fitness as the days pass. 

However, I'm probably not the only person who worries about losing fitness. Many people have lost their fitness during this Covid pandemic. I remember a few of my patients who are security officers for ministers/ VIP's whose ability to train while on duty is severely restricted. Similarly for military personnel on certain postings. Others with personal conflict, family commitments, caring for an ill family member and injury may face the same situation.

Since I'm in the same boat, I'm reading up to find out exactly how or what I need to do so I don't lose too much, or better still maintain whatever fitness I have left 2 weeks post accident.

Let me share what I found out from researchers from the US Army Research Institute of Environmental Medicine. They looked at three key training variables, frequency (how many days a week), volume (how long the session, how many sets or reps to lift) and intensity (how hard or how heavy the weight). 

Only studies on athletic performance (not weight loss or health) in which the training was reduced for at least 4 weeks were considered. This is to distinguish them from research on tapering before a big competition (usually a 3 week taper).

Most of the studies reviewed were based on work done by Robert Hickson in the early 1980's (Hickson and Rosenkoetter, 1981). Hickson's subjects were put through 10 weeks of brutal training. They involved 6 days of cycling or running for 40 minutes at 90-100 percent maximum heart rate (HR) at the end. Then for the next 15 weeks, they reduced the number of weekly sessions to twice or four times a week. Duration was reduced to 13 or 26 minutes and intensities of the sessions were reduced to 61-67 or 82-87 percent of max HR.

Picture from Med Sci Sp Ex article

In Hickson's original study , VO2 max is shown on the Y (or vertical axis) on the left of the picture above. You can see that after the 10 weeks (albeit brutal) training block on the X axis, VO2 max have improved by a impressive 20-25 percent. For the next 15 weeks, their VO2 max stayed at their improved values, despite training dropping down to 2-4 days a week. The subjects were recreationally active but untrained. 

Overall conclusion of this review is that you can get away with just 2 sessions a week as long as you maintain volume and intensity of your workouts. This is similar to what Hickson found with further confirmation in some areas. 

However, please bear in mind that maintaining your VO2 max is not the same as your ability to perform long duration activities (oops for me then since my Saturday bike rides go up to 3 hours). Similarly, don't expect to run your best marathon time after a few months of 2 times a week training. Your leg muscles will definitely not be able to handle it.

When duration of training was reduced by one (13 minutes) or two thirds (26 minutes), VO2 max gains were preserved for 15 weeks. The study included short (5 minutes) and long (2 hours) endurance. No prizes for guessing that short endurance was preserved when comparing the 13 and 26 minutes group, but those who reduced their training to 13 minutes fared worse in the 2 hour test.

When training intensities were dropped by a third (from 90-100 percent to 82-87 percent), VO2 max and long endurance declined. When training intensities were dropped by two-thirds (61-67 percent), most of the training gains were wiped out. Takeaway message is you can get away with training less often, or for a shorter duration but not with going easy.

A few other points to note. These conclusions were based on what I'll say is an "unsustainable training protocol" of hammering 6 days a week with one rest day! Most of us would surely have a more balanced training program of hard and easy days. 

The subjects used were not trained athletes nor military personnel. If you've been  training for years, you would have some structural changes like a bigger heart and a more extensive network of blood vessels that would hopefully take longer to take away (yay for yours truly).

Of course elite athletes would probably have a higher level of absolute fitness which may fade away quicker initially.

All you gym rats will be happy to know that the overall pattern is fairly similar when it comes to strength training too. Both frequency and volume of workouts can be reduced as long as intensity is maintained. Several studies found that even once a week training is enough to preserve maximum strength and muscle size for several months.

However, for adults above 60, evidence suggests that twice a week strength sessions are better at preserving muscle. Same for training volume, older people will need two sets while one set per exercise for young populations will suffice.

Now you (and I) definitely know what it takes. 

References


Hickson RC and Rosenkoetter MA (1981). Reduced Training Frequencies And Maintenance Of Increased Aerobic Power. Med Sci Sp Ex. 13(1): 13-16

Sperring BA, Mujika I, Sharp MA et al (2021). Maintaining Physical Performance: The Minimal Dose Of Exercise Needed To Preserve Endurance And Strength Over Time. J Strength Cond Research. 35(5): 1449-1458. DOI: 10.1519/JSC.0000000000003964


No comments:

Post a Comment