A couple of days ago, I wrote about whether weight machines or free weights were the better choice for the older weight trainer, and I concluded based on information I found online and my own personal experience, that in general, it’s best to start out weight training with machines and then gradually add free weights to your routine. Ultimately, you could completely switch from machines to free weights and plate loaded weight machines.
The debate over which type of weight training equipment is optimal for building lean muscle mass has been raging for decades but it’s not the only one. There’s also the argument about using heavy weights with fewer reps vs. lighter weights with more reps.
Lighter vs. Heavier
Conventional wisdom over the past several decades has said that to get big you have to lift heavy. However more recent research is suggesting that using lighter weights and increasing the number of reps and sets to make the overall intensity of the workout the same as someone lifting heavier will produce the same result.
This might sound like good news to a lot of you out there who are concerned that lifting heavier weights, especially dumbbells and barbells, is more risky. Let’s take a brief look at this topic.
According to an article at MensHealth.com, Brad Schoenfeld, Ph.D., C.S.C.S. performed a meta-analysis of 13 studies on using heavy vs. lighter weights and building muscle which was published in Sports Medicine.
The conclusion was:
When people performed exercises that were less than 60 percent of their one-rep maximum to fatigue, they saw gains equivalent to their heavy-lifting counterparts over 6 weeks.
Even if you can lift heavy, you should consider lifting lighter loads once in a while, too, says Schoenfeld. You’ll maximize a muscle’s full potential, working both its fast-twitch and slow-twitch fibers. Plus, lighter loads put less stress on your joints, tendons, and ligaments than bigger loads, decreasing your risk of injury. Schoenfeld suggests training with lighter weights one day every week or every two weeks.
MensFitness.com cites research done at McMaster University and published in the Journal of Applied Physiology that compared three different groups of men. The first group performed three sets to fatigue at 30% of one-rep maximal strength, the second performed one set to failure at 80% of one-rep max, and the third group performed three sets to fatigue at 80% of one-rep max.
At the end of 10 weeks, it was found there was no difference between the three groups in terms of gains in muscle volume. The results of the same study were also published online at AceFitness.org.
Labrada.com published a more extensive set of research on the topic and was the first article to mention anything about older people:
The old lady does light high rep sets in order to practice correct exercise form, develop basic conditioning, and avoid injuries. The muscular bodybuilder does light high rep sets in order to add variety to his relatively intense training program and thereby get muscle stimulus from a new type exercise stress, which is necessary for continued training progress.
Even though both the old lady and the muscular bodybuilder might periodically be working out at the same relative intensity (that is, the same percentage of their respective 1RM), the bodybuilder will of course be moving much heavier weight than the old lady because his maximal strength is so much higher.
So you can lift a lighter weight for a given exercise than someone who is younger and lifting heavier and you will still see positive gains as long as you are, at least periodically, both working at the same relative intensity.
This figures into what I found in an article on this debate at Shape.com addressing women who weight train:
While lifting lighter weights can be less intimidating, more convenient (you don’t need a spotter) and a better option for those who are older, strength training with lighter weights does mean that it takes more reps and more time to get to that sweet spot of total exhaustion. So people who are in a hurry? Heavy is still probably best.
Additionally, most women probably need to reconsider what they consider “light,” Olson says. In the study, woman lifted at minimum 30 percent of their max. For the average 145-pound woman, a maximal squat is about 130 to 135 pounds. Therefore, lifting a “light” amount in this study would equate to doing about 25 to 30 reps holding 15- to 20-pound dumbbells.
It’s fairly common for novice weight trainers, especially older ones, to underestimate the target weight to lift that will allow them (us) to make gains in muscle growth and strength. The general recommendation would be to choose a weight that would lead to failure (you can’t lift the weight one more time, at least not without cheating) within 12 to 15 reps in the first set.
But assuming you clicked on the links I provided, you may have run into some terms you didn’t understand. Knowing what they mean will help us better zero in on how we construct our weight training routines.
Slow and Fast Twitch Muscles
What? Isn’t muscle just muscle? Like most things about our bodies, there’s a lot more going on than we typically are aware of.
According to an excellent article I found at SportsMedicine.com:
Slow Twitch (Type I)
The slow muscles are more efficient at using oxygen to generate more fuel (known as ATP) for continuous, extended muscle contractions over a long time. They fire more slowly than fast twitch fibers and can go for a long time before they fatigue. Therefore, slow twitch fibers are great at helping athletes run marathons and bicycle for hours.
Fast Twitch (Type II)
Because fast twitch fibers use anaerobic metabolism to create fuel, they are much better at generating short bursts of strength or speed than slow muscles. However, they fatigue more quickly. Fast twitch fibers generally produce the same amount of force per contraction as slow muscles, but they get their name because they are able to fire more rapidly. Having more fast twitch fibers can be an asset to a sprinter since she needs to quickly generate a lot of force.
Further, fast twitch or Type II muscle fibers can be further separated as Type IIa and Type IIb, with Type IIa muscle fibers being intermediate fast-twitch that can make use of both aerobic and anaerobic metabolism, and Type IIb fibers using exclusively anaerobic metabolism.
What does this mean as far as weight training using heavy weight and fewer reps vs. lighter weights and more reps?
Bodybuilding.com published information about these two (three really) muscle fiber groups and determined (you’ll have to scroll to the bottom of their web page to see the chart illustrating this) that for Type I muscle fibers, the more reps you can perform per set the better. The recommended number of reps for excellent growth potential was between 25 and 50. Anything from 13 to 15 reps was good, and 16 to 25 reps was better.
For Type IIa muscles, 9 to 12 reps per set was considered the optimal range, with benefits decreasing if you performed either fewer reps or more reps. For Type IIb muscle fibers, the optimal range of reps was from 6 to 8. When either fewer reps were performed per set or more reps, benefits also decreased.
Given this information, it would seem to indicate that during some workouts, you should use lighter weights and much higher reps to hit Type I muscle fibers, and for others, use heavier weights that allow you to perform an intermediate to lower number of reps.
So for example, if you perform a full body workout twice a week, you could do lighter weights and more reps the first day and heavier weights and fewer reps the second. Alternately, you could do one week lighter and one week heavier, or only have a “light” day once every several weeks. Remember, “heavier” and “lighter” are relative terms and what’s heavy to you might be lighter to another person. The amount of weight you select for any given exercise should be sufficient to allow the target number of reps ending in failure.
Note: Remember there’s a difference between functional failure, which is the inability to do one more rep without sacrificing form or performing a cheat, vs. absolute failure which is the inability to lift the weight one more time no matter what. For seniors, it’s recommended to go to functional failure.
Also, in an article written by Gilbert Neyens on his blog Lifetime in Shape, he says that doing “more reps with less weight will cause the smallest blood vessels, called capillaries, to improve because when training on muscle endurance the trained muscles need a lot of oxygen. The body will adapt to the training and the capillaries improve to let more blood and oxygen go to the trained muscle.” From the way I understand this, I could improve my stamina on those exercises that really wipe me out like bent over rows and deadlifts (see more about them below) if I periodically go lighter and do more reps rather than continually going heavy and exhausting myself.
One Rep Maximum
In the studies you should have reviewed, you probably saw that different groups in these studies were organized by the percentage of their one rep max they were performing, usually either 30% or 80% to 90%.
In simplest terms, a one rep max is the amount of weight you can pull or push for only one rep before failure. That’s a lot of weight. I haven’t had the nerve to even see how much weight I can perform only one rep for any given weight training exercise, but remember, these studies were conducted using much younger people, men in most cases, and there was plenty of support under controlled conditions.
In order to calculate percentages for a one rep max, you’d think you’d have to know what that max value is to begin with. Fortunately, that’s not true. There are plenty of one rep max calculators online, including at Bodybuilding.com. For example, lets say I selected a barbell weight for a bent leg deadlift where I could perform a maximum of 10 reps in the first set. I enter that weight into the available field of the calculator, select the number of reps I performed (from 1 to 10), and then click “Compute.”
The calculator produces a value for how much weight would be my One Rep Max on that exercise, plus the various weights I could lift representing different percentages of that value.
Unless you are conducting a scientific study or have constructed a very precise workout routine that requires you to know such exact information, this may not be much use to you. I usually “listen” to my body as far as my capacity to lift a weight a certain number of reps, both in terms of achieving failure in lifting and in what I consider failure in relation to stamina (even if I could continue lifting).
I know on a dumbbell incline bench press, I lift until I can’t push the weight up one more time. This is usually because my triceps fail rather than my chest or delts, but the result is at failure, I can only get the weight up part way and no amount of effort on my part will get it to go higher.
Then, there are exercises like the dumbbell bent over rows or any deadlift. I know I can lift more weight for more reps than I currently do, but even at my current levels, at the end of each set, I’m out of breath, my heart is pounding, and I’m dripping with sweat. Technically, I didn’t lift to failure, but then again, I’m not stupid either. If I push myself to absolute exhaustion, the workout will drain me to the point where It will take hours and hours to recover (remember how I felt when I tried to do an hour of cardio after weight training my biceps and triceps). Training to complete exhaustion over time will diminish my overall health, not improve it.
My body tells me that there’s a functional upper limit on certain exercises that I should pay attention to in terms of stamina and endurance, if not actual muscle strength, and I’d be an idiot not to pay attention to that message.
In order to work all of your different muscle fibers and maximize your potential for muscle gains, you’ll need to vary your weight training workouts periodically, on some days using lighter weights and more reps for your exercises, and on other days, choosing heavier weights and performing fewer reps per set.
Remember though that “heavier” and “lighter” are relative terms, and what you’re going for is varying degrees of workout intensity. For Type I muscle fiber days, the lighter weights should enable you to perform something like 20 to 25 reps or more for the first set, and for Type II muscle fiber days, you should aim for a weight that lets you do 6 to 8 or 9 to 12 reps for the first set.
I’ve also said in the past, that my compromise most of the time is to choose weights that let me perform up to 15 reps for the first set. Sometimes I go lighter and sometimes heavier, but across three sets, I almost always try to perform 8 or more reps for the second and third sets.
However, this variable method actually should break up the monotony of performing the exact same routines day in and day out and will add variety to your weight training. Also, switching things up periodically is a good way to break through weight training plateaus where you seem to be stuck at the same weight for an exercise for weeks or months at a time.
Just pay attention to how your body is responding. Yes, you want to push your limits and to define “heavier” as a little more weight than you thought you could do, but when your body really is saying “stop” then stop. It’s true you want to work harder and achieve gains, but injury or exhaustion is never part of a good exercise plan.
Information is power. The more you know, the more you’ll know what to do and how to do it.
Your only obligation in any lifetime is to be true to yourself.