MINI-REVIEWS

LIFT FAST OR LIFT SLOW?

A recent paper out of Spain (http://www.ncbi.nlm.nih.gov/pubmed/24734902) investigated whether doing bench press repetitions at maximal velocity or doing repetitions with the same weight at slower repetitions created more strength gain. The researchers did not state a specific hypothesis, they simply stated that:

“The purpose of this study was to compare the effect on strength gains of two isoinertial resistance training (RT) programmes that only differed in actual concentric velocity: maximal (MaxV) vs. half-maximal (HalfV) velocity.”

They used 20 subjects in their velocity experiment and trained them on the bench press 18 times over six weeks. They did max testing before the start of experimental training and after the experimental training ended.

The main conclusions of this section of the paper (there was a lactate section not discussed  here) is that time under tension (how long the muscle is loaded during a repetition) is not a factor in strength gain as the slow sets were under tension for 62% longer than the fast sets. The researchers further go on to state:

“the results of this study show that movement velocity can be considered a fundamental component of resistance exercise intensity, since, for a given loading magnitude (%1RM), the velocity at which loads are lifted largely determines the resulting training effect”

Interesting findings, but as always we can’t take the researchers word for this, we need to contextualize their paper. There are problems we see when we objectively evaluate their paper.

Their subjects were male college exercise science students weighing 71kg (156lbs) who had “recreationally trained” using the bench press over the previous 2-4 years. The rationale for stating 2-4 years of previous experience is to demonstrate that the outcomes of the experimental training would not be affected by novice motor learning and novice neural adaptations. The reviewers bought this as a control but let’s look closer.

The average weight that the 20 subjects could bench press prior to experimental training was 74.8kg (165.6lbs). When their age, gender, and bodyweight are considered against performance standards, the subjects are in the “novice” category (see the Bench Press standards at http://kilgoreacademy.com/freebies.html). So while the researchers suggest that early stage adaptions did not affect the results, we can clearly see that there was a strong likelihood that novice adaptations were the primary drivers of the results seen, and bar velocity cannot be construed to be the primary stimulus of strength gain in this group.

Another issue that strongly affects our ability to generalize these data to doing the bench press in the gym is that the researchers used a Smith machine as the apparatus. While using the Smith machine makes calculations of work done easy (it’s a straight line) it is not reflective of the curvilinear trajectory of most gym machines and it definitively does not require the level of motor control and stabilizing muscle input seen in free weight bench presses. The findings are specific to the Smith machine.

However, the use of the Smith machine may have unintentionally worked in favor of supporting the researchers finding. Both the Fast Training and Slow Training groups got significantly stronger, but the Fast Training group had a statistically, and practically, significant larger increase:

FAST: 1RM pre-training = 75.8kg – 1RM post-training = 88.2kg

SLOW: 1RM pre-training = 73.9kg – 1RM post-training = 80.8kg

So how did using the Smith machine accidentally make these data stronger? Think about it. By using the Smith machine, a very large neural component, the need for motor control and coordination was eliminated from each repetition. Improvements in motor control and coordination are large contributors to novice fitness performance gains. By reducing their influence on the experimental outcomes, the results become stronger, although by no means are they conclusive or extremely useful – novice mechanisms of strength gain, which may render the findings non-generalizable, still cannot be ruled out.

What we do see here is a small bit of evidence that says doing repetitions at higher velocities creates better strength gains than slow velocities. This really isn’t new and earth shattering information, as coming up on 25 years ago it was noted that simply thinking about trying to move a big weight faster during a repetition (even though it moved slowly) produced better results than just thinking about grinding through it (http://www.ncbi.nlm.nih.gov/pubmed/8444715). This new data also cannot settle the ongoing argument between max velocity proponents and time under tension proponents, BUT it is a data point that both sides will probably use as there are takeaways for both sides.


DON’T WANT TO WALK LIKE AN OLD MAN? IT’S AN EASY FIX.

In an interesting recent article, “Slower Walking Speed in Older Men Improves Triceps Surae Force Generation Ability”, a comparison of gastrocnemius and soleus function was conducted between 25 year old and 73 year old males during walking at each individuals preferred walking speed. As one might expect, older subjects walked more slowly than their 50 year younger counterparts. This is in fact the primary interest of the researchers, why do the elderly walk slower?

The paper looked a number of measures down to the muscle fascicle level where it was determined that muscle shortening velocity was lower in the older subjects. Their conclusion from their experiments can best be summed up with the final line of the abstract:

“The results suggest that older men may prefer slower walking speeds to compensate for decreased plantarflexor strength.”

And this makes sense, if you are weak you move at a higher relative metabolic cost so you take it slow and you take it slow since balance, specifically the control of balance, requires strength.

So the easy fix? You already know, get stronger. If, as an aging individual, you want to maintain your mobility then you just have to get to the gym and train.

It’s very irritating that the paper is not available except through a pay-gate, so I can’t give you a link to it. What I can do is go one better, click here to download a pdf of the doctoral dissertation from which the paper derives.


RESEARCH I WANT TO BELIEVE

I really do. It’s a catchy title; Coffee treatment prevents the progression of sarcopenia in aged mice in vivo and in vitro. It’s an interesting study, but done in mice, so it is possible the findings won’t be generalizable to humans:

“In this study, using aged mice, we showed that coffee treatment increased the skeletal muscle weight, grip strength, regenerating capacity of injured skeletal muscles, and decreased the serum pro-inflammatory mediator levels compared to controls in vivo. In vitro, coffee treatment increased the cell proliferation rate, augmented DNA synthesis, and activated the Akt signaling pathway compared to controls in the satellite cells of aged mice.”

While the researchers were most interested in how coffee consumption affected the loss of muscle cells (sarcopenia), they didn’t actually count the number of muscle cells pre and post-treatment. They used muscle weight as a proxy and as muscle weight was larger in coffee treated mice they concluded that muscle cell loss didn’t occur. If it did muscle weight would have gone down. There are conditions that this relationship would not be present, so this experiment should be repeated with muscle cell enumeration at some point.

I look at this paper not as a paper on preventing loss of muscle mass in the aged, I look at it as a training and adaptation paper. Everything that is presented as a finding indicates that adaptations to training could enhanced with daily coffee consumption. That seems pretty cool.

But there are always the inevitable “buts” in science. The coffee used in the study was bottled ready-to-drink coffee. In fact, it was half-strength ready-to-drink coffee with nothing added but water, not the fresh brewed concoction you get from your favorite coffee shop or from your home based espresso machine. Would standard brewed coffee or an equivalent strength Americano produce similar results or would the higher concentrations of caffeine, acids, and polyphenols blunt, accentuate, or have no effect on the outcomes? Would the addition of milk and any other customization of flavor profile affect the outcomes? The mice also drank coffee as their only source of hydration, so would a single daily dose of coffee in the morning create the same outcomes? Are these effects restricted to the old and not apparent in the young? All this is currently unknown.

What we can loosely draw from this paper is that if you have trainees, or you yourself, who drink daily coffee, the outcomes of that training will likely not be negatively affected by that coffee consumption. Suggesting that drinking half strength coffee all day for many weeks could be anabolic and contributes to muscle adaptation and performance would be premature.


Older populations that are functionally limited in movement should lift weights

One of the few jokes I can ever remember was one I heard as a tiny kid in the early 1960s Las Vegas. Danny Thomas was performing at the Horseshoe and told the joke:

“I tripped and fell last week and my elbow was playing up bad. So I goes into the doctor’s office and say ‘Doctor, Doctor, it hurts when I do this’ (physical comedy here). The doctor, looks at me, thinks and says ‘Don’t do that’.”

At six years old, it was a funny joke. At almost 60 years of age I see it as the approach to life and pain management that most people my age take, if it hurts, even a tiny little bit, they don’t do it. It sounds logical but it is absolutely the wrong approach in almost all instances where exercise and aging are considered. Becoming more fit tends to reduce pain, alongside all the other beneficial functional outcomes.

There was a nice paper by Kraschnewski and co-workers about this phenomena out a couple years ago (that I’m just now getting around to discussing). Although once again it’s a study made weaker by the use of subject self-report as data, the paper, in Preventive Medicine, suggests that older individuals don’t lift weights but that they should, especially if they have functional impairments. The data is interesting suggesting that only 16% of older adults lift weights with a high enough frequency to be effective. There was a direct relationship between having a physical limitation and not lifting weights (the more limitations presence the lower frequency of participation). 

The following passage is indicative of the findings and suggest direction for interventions:

“those with the greatest number of functional limitations should be performing ST the most. This expectation is similar to the observation that patients with the highest blood pressure should have the highest rates of antihypertensive medication use. Unfortunately, we found an opposite relationship; those with more functional limitations were consistently less likely to meet ST guidelines. This suggests the untapped potential of ST to improve the public’s health by properly targeting older adults most in need. Though ST has the potential to help people reverse functional limitations, more than 80% of affected older adults are not doing enough ST to likely improve those limitations. Notably, functional limitations are not only concerning for loss of independence, but are associated with both increased health expenditures and risk of death.”

So those of us who are masters or who train masters need to ensure strength training is a regular element of programming and that we get the word out – more successfully than we have historically – that lifting does the aged body good, despite the aches and pains we might have.