Osteopenia | ViiV Fitness Blog


By Brian Murray, M.Ed.
Director of Clinical Research, ViiV Fitness

Fast Velocity Resistance Training

Did you know you can train fast without any movement whatsoever?

I recently stumbled upon a 2019 review article published in Strength and Conditioning Journal titled: "Why Fast Velocity Resistance Training Should Be Prioritized for Elderly People". This small review of 56 studies compared the improvements in muscle strength, power output, explosive force, muscle mass, and functional capacity after resistance training with slow or fast contraction velocities in older adults. 

The Summary?

Fast velocity resistance training is superior for improving maximal isometric strength, power output, explosive force, and functional capacity; all things that every person needs and should strive for, no matter what their age or level of physical fitness.  

But why are the results better with fast velocity training?

The Rate of Force Development is faster.

And so I realized this paper could easily be re-titled: "Why Five Seconds of All Out Isometric Effort Should be Prioritized for Everyone".


Five seconds of maximum isometric effort on the ViiV-Rx and intentionally moving a weight as fast as possible have something in common: the rate of force development is fast.

This is important. 

The faster rate of force development makes people more powerful, capable, and independent by protecting the larger, stronger neuromuscular units that become inactive and largely account for age-related weakness (See my previous article titled AGE-RELATED WEAKNESS: NERVE OR MUSCLE).

Roughly 80% of our population doesn't get any exercise. About 50% are Baby Boomers, the group of people that desperately need improved power output and functional capacity the most.

With ViiV, we have the ability to make older individuals more powerful without any movement whatsoever, and this capability is then ready and waiting for them to use as they move throughout their daily activities. 

Our bodies need to move regularly, but we can become better movers with a few seconds of no movement.  


By Brian Murray, M.Ed.
Director of Clinical Research, ViiV Fitness

age related muscle weakness

For a long time now it has been assumed that the primary cause of the age-related decline in strength is the loss of muscle mass. Consequently, medications were developed to act on muscle to enhance muscle function and physical capacity. Unfortunately, all of them failed, and for a good reason.

It's not about muscle.

A 2019 paper by Clark et. al. titled Voluntary vs Electrically Stimulated Activation in Age-Related Muscle Weakness studied the role of the nervous system in clinically meaningful age-related weakness in a cross-sectional group of 66 older adults (age range 67 to 85 years). Participants were characterized as weak (the oldest group with an average age of 78.4 years), modestly weak (average age 74.9 years), or strong (the youngest of the bunch with an average age of 72 years). The researchers specifically sought to determine if weak older adults exhibit reduced ability to activate their lower extremity muscles compared to their stronger counterparts. The degree of voluntary inactivation was calculated for each group by comparing maximum voluntary and electrically stimulated muscle forces.

The results of this study found that the weak older adults exhibited significantly higher levels of voluntary inactivation compared to the strong older adults (14.2% vs 7.1%). What makes these findings even more interesting is the fact that lean thigh mass for all three groups was nearly identical.

Think about this. Same muscle mass, dramatically different ability to activate that muscle mass. That's pretty strong evidence that age-related weakness is not necessarily a disorder of the skeletal muscles. In fact, Dr. Clark stated "It's confirmatory evidence that the nervous system is a key culprit in weakness."

In a 2009 study by Delmonico et al. titled Longitudinal Study of Muscle Strength, Quality, and Adipose Tissue Infiltration, 1,678 participants were followed for 5 years. It was found that loss of muscle torque was 2-5 times greater than the loss of muscle cross sectional area. In other words, loss of strength was weakly associated with loss of muscle mass. So something else accounted for the large drop in strength.

It's the nervous system.

This fact is why the ViiV-Rx Isometric Machine is the perfect tool for reversing age-related weakness, increasing strength with advancing age, and preserving that strength 'til death do us part. It's perfect because isometrics are the most effective and efficient way of producing changes in the nervous system that really matter for improving physical capacity.

Here's why:

Performing a maximum voluntary isometric effort in your most efficient joint angle for producing maximum force leads to the greatest improvements in strength and neurological efficiency (Read my previous article ViiV-Rx Makes Weight Lifting Obsolete?). Isometric contractions also yield far greater improvements in voluntary activation compared to concentric or eccentric contractions.

For nearly 20 years now I have had clients give it everything they've got for 5 seconds at 1-4 stations. I have worked with people of all ages for many years in a row, many of them in their 80's. I have yet to see someone max out their strength or lose their ability to voluntarily activate their muscles over time. My experience has shown me that no one is too old or too inactive to reawaken dormant nervous system pathways and achieve life-changing-long-lasting improvements in physical capacity.

Age-related decline in muscle strength? Nah. The muscles are just fine.

It's all about your nerves.

The ViiV-Rx is the perfect nervous system anti-aging treatment.

Problem solved.


Obviously someone noticed a change in Jill, and now three weeks after her first few sessions others have noticed a change in Jill as well. Even Jill's sister, who had not seen Jill in nearly 4 months couldn't believe how much better she was walking. And no, she still has not told anyone what she is doing.