Here’s how to answer the questions
members or clients most often ask fitness professionals.
Every
day, fitness professionals are faced with a multitude of questions—on topics
ranging from losing weight to rehabilitating injuries. While it is difficult to
know all the answers, providing clients with ready responses can be a testament
to your professional credibility. This article addresses some of the more
popular questions clients ask and provides the information you need to answer
them quickly.
1. What Is the Best Way to Lose Fat?
The
simple (and complex) answer is that there is no “best way” to lose fat. Each
client will respond differently to a training program. However, there are some
principles fitness professionals can apply when designing their clients’
programs.
Activities
that incorporate many muscle groups and are weight bearing use more calories
per minute and are therefore better suited for fat loss than non-weight-bearing
activities that do not use many muscles.
It
is often assumed that low-intensity exercise is best for burning fat. During
exercise at a very low intensity, fat does account for most of the energy
expenditure, while at a moderate intensity, fat accounts for only about 50
percent of the energy used. However, since the number of calories used per
minute is much greater at a moderate to high intensity than at a low intensity,
the total number of calories expended during a moderate- to high-intensity
workout is greater than it is during a low- intensity workout of the same
duration; consequently, the total number of fat calories expended is also
greater during the higher-intensity workout. The rate of energy expenditure,
rather than simply the percentage of energy expenditure derived from fat, is
important in determining the exercise intensity that will use the most fat.
Furthermore, endurance-trained individuals rely less on carbohydrates and more
on fat as a fuel source during submaximal exercise (Kiens 1997). Thus, the more
aerobically trained your clients become, the more fat they will use during
subsequent exercise sessions.
To
decrease body fat percentage, your clients do not necessarily have to use fat
during exercise. Much of the fat from adipose tissue (as opposed to
intramuscular fat, which is primarily used during exercise) is lost in the
hours following exercise. Moreover, the amount of fat lost
after a workout depends, in part, on the exercise intensity during the
workout. Following high-intensity exercise, the rate of fat oxidation is higher
than it is following low-intensity exercise (Mulla et al. 2000; Phelain et al.
1997). Because clients can perform a greater intensity of work if the work is
broken up with periods of rest, interval training is a great way to perform
high-intensity work and help decrease body fat percentage.
Both
strength training and endurance exercise have been shown to decrease body fat
percentage. However, aerobic exercise appears to have a greater impact on fat
loss than does strength training (Ballor et al. 1996; Dolezal & Potteiger
1998; LeMura et al. 2000). A combination of endurance and strength training
results in more fat loss than either exercise regimen alone (Dolezal &
Potteiger 1998), possibly because clients who perform both activities spend
more time exercising.
2. If I Lift Weights, Will I Get
Bigger Muscles?
Whether
or not your clients will get bigger muscles (hypertrophy) depends on three
basic factors: genetics, gender and training intensity. Genetics is mostly
manifested as muscle fiber type; people with predominantly fast-twitch fibers
acquire larger muscles more easily than people with predominantly slow-twitch
fibers. In relation to gender, males acquire larger muscles than females do,
because males have greater amounts of testosterone and other sex hormones that
influence protein metabolism (Tipton 2001). Thus, females experience less
muscle hypertrophy with strength improvement than males do (Lewis et al. 1986).
Training intensity is the only factor you can control.
Hypertrophy
results from an increase in the number of contractile proteins (actin and
myosin, produced by the body in response to training), which in turn increases
the size of the muscle fibers.
If
the training goal is hypertrophy, the load lifted should be at least 80 percent
of the one-repetition maximum (1 RM), as a general guideline (Zatsiorsky 1995).
If your clients are not interested in developing larger muscles, keep the load
less than 80 percent of 1 RM. However, hypertrophy can be stimulated any time
the training intensity is high enough to overload the muscle. Thus, in an unfit
client who has never lifted weights before, 60 percent of 1 RM may be enough to
cause slight hypertrophy, especially if the client is predisposed to
hypertrophy by having a large proportion of fast-twitch fibers.
3. How Do I Get a Flat Stomach?
Genetics
also plays a role in whether or not your clients can obtain a flat stomach or a
“six-pack” look to their abdominals. Having said that, two types of exercise
can help: strength training and cardiovascular exercise. The abdominals are
just like any other muscle group: For their definition to become visible, they
must grow larger and the fat that lies over them must decrease. What makes the
definition of the abdominals so difficult to see is that they are situated in
the area of the body that contains the most fat. Strength training the
abdominals is only half the story. Your clients will get a flat stomach only if
they combine strength training with cardiovascular exercise to get rid of the
fat. Most clients do not do nearly enough cardiovascular exercise to decrease
their body fat percentage to a point where they would see their abdominals.
Even when the aerobic exercise stimulus is adequate, the role of diet must not
be underestimated. All people with a flat stomach or six-pack have a very low
percentage of body fat.
Abdominal
crunches are just as effective as any piece of equipment to train the rectus
abdominis muscle, the main muscle in the abdominal region (Demont et al. 1999;
Vaz et al. 1999). As your clients improve their abdominal strength, they can
make crunches more demanding by performing them on a movable surface, such as a
resistance ball (Vera-Garcia et al. 2000).
4. Should I Do Cardio First or Weight
Training First?
It
depends on the client’s goals. Many personal trainers think that performing
strength training before cardiovascular exercise will augment the amount of fat
used during the cardio workout because the strength training will deplete the
muscles’ store of carbohydrates (glycogen). However, strength training is not
likely to deplete glycogen stores, because a lot of the workout time is spent
resting between sets and exercises. Even if the strength workout were long and
intense enough to accomplish this task, exercising in a glycogen-depleted state
has many negative consequences, including an increase in acidic compounds
produced in response to low carbohydrate levels, low blood insulin,
hypoglycemia, increased amino acid (protein) metabolism, increased blood and
muscle ammonia and a strong perception of fatigue. Currently, no research shows
that strength training immediately before a cardio workout increases the amount
of fat used during the cardio workout, or vice versa. Most likely, the intensity of
the activity, not the mode of exercise, determines the “fuel”—either fat,
carbohydrate or protein—that is used. However, if clients strength train first,
it is possible that muscle fatigue incurred from the strength training could
cause them to decrease the intensity of their subsequent cardio workout, thus
leading them to expend fewer calories over the workout as a whole.
If
the primary goal is to increase aerobic endurance or lose weight, then the
client should perform cardiovascular exercise first. If the primary goal is to
increase muscular strength, then the client should perform strength training
first. Basically, in order to get the most out of the workout, the client should
perform the most important type of exercise when he or she is not fatigued.
Because many clients want to lose weight and increase muscular
strength, alternating the order of the workout during different cycles of
training is one way to satisfy both goals.
5. Do I Need to Take Dietary
Supplements?
Your
clients do not need dietary supplements unless they have a documented vitamin
deficiency or they do not eat a balanced diet. Using supplements as an
alternative to a sound diet can lead to serious deficits in the consumption of
other nutrients (Benardot et al. 2001). It is always healthier to acquire
vitamins and minerals from food than to obtain them from a pill. However,
serious vitamin deficiencies do occur in a small proportion of the population
(Benardot et al. 2001), and supplements are useful for making sudden
improvements in vitamin status.
Supplements
for losing fat or building muscle are rapidly becoming popular. Claims that
“fat-burning” supplements will decrease body fat by increasing either mobilization
or oxidation of free fatty acids (FFAs) are faulty at best. Untrained
individuals have a greater ability to mobilize FFAs than they do to oxidize
them. Therefore, supplements that increase FFA mobilization are not of any
value for untrained people. For supplements to directly enhance FFA oxidation,
the insulin response to the carbohydrates in those supplements would need to be
eliminated (since insulin inhibits fat oxidation), and this is unlikely to
happen (Coyle 1995). Exercise alone increases the muscles’ capacity to oxidize
FFAs.
For
those who eat a balanced diet, there is no evidence that muscle-building
supplements, including protein powders and amino acids, build muscle mass
(Clarkson 1998; Eichner et al. 1999). The few supplements whose muscle-building
potential is supported by research (e.g., creatine) are effective mostly in
elite athletes who have undergone many years of training (Eichner et al. 1999).
6. What Is My Target Heart Rate?
Target
heart rate—the heart rate range used to determine the desired intensity of an
activity—will differ depending on the goal of the workout. You can calculate
target heart rate using a percentage of your client’s heart rate maximum
(HRmax), which can be predicted by subtracting your client’s age from 220, or
by measuring your client’s heart rate while he or she performs a maximum
exercise test. You can also calculate target heart rate using the Karvonen
method, which takes into account your client’s resting heart rate (RHR).
Subtract your client’s RHR from his or her age-predicted HRmax before
multiplying the outcome by the desired percentage. Then add the RHR back onto
that value. The difference between HRmax and RHR is called heart rate reserve
(HRR).
Since
RHR will decrease as cardiovascular fitness improves and HRmax can decrease
with age, periodically recalculate target heart rate as your clients become
more fit (or more sedentary) and get older. Age-predicted HRmax may be off by
more than 10 to 15 beats per minute, since all people of the same age do not
have the same HRmax. Therefore, it is much more accurate to directly determine
HRmax with a maximum exercise test. Use HRmax, but don’t forget to consider
subjective factors, such as how the client feels.
When
the workout goal is to increase aerobic endurance, target heart rate should be
65 to 80 percent of HRmax (about 55%-70% of HRR). During interval training,
which focuses on increasing cardiovascular performance, target heart rate
should be greater than 80 percent of HRmax (70% of HRR).
7. What Is the Difference Between
Weight Machines and Free Weights?
Ignoring
the effect of gravity in creating resistance during all movements, free weights
(dumbbells) keep the resistance on the muscle constant throughout the joint’s
range of motion (ROM), while weight machines use variable resistance, with the
resistance changing throughout the ROM. Machines have geometrically shaped cams
that change the torque required of the muscles by changing the lever arm of the
resistance force (external weight) or the applied muscular force. Thus,
machines place more stress on the muscles at the angles at which muscles can
produce greater force. Since there are points in a joint’s ROM where the muscle
is stronger and points where it is weaker, and the amount of weight your
clients can lift is limited by their weakest point, free weights serve only as
a strong enough training stimulus for the weak joint positions. With machines,
the load changes to provide optimal resistance throughout the entire ROM.
On
the other hand, movements using free weights occur in a three-dimensional
plane, while most weight machines allow movement only in a single plane. With
machines, the movement is guided, so only the major muscles required to perform
the movement are used. With free weights, the added task of balancing the
weights in the three-dimensional plane recruits other functional muscles that
machines do not recruit.
Clients
new to weight lifting should probably begin with machines to train the major
muscles, and then use free weights to train more specific movements.
8. Why Are My Muscles Sore After a
Workout?
Soreness
results from high force production when an exercise is new or a load is greater
than normal. Furthermore, eccentric muscle contractions (in which the muscle
lengthens, as when lowering a weight) cause more soreness in the days following
the workout than either isometric contractions (in which the muscle does not
change length, as when holding a weight) or concentric contractions (in which
the muscle shortens, as when lifting a weight). This soreness in the days after
exertion is called delayed onset muscle soreness (DOMS) (Armstrong 1984;
Clarkson & Sayers 1999). Although many people think that lactic acid is the
cause of muscle soreness, the fact is that lactic acid (lactate) is removed
from the muscles within 30 to 60 minutes after exercise, so it is long gone by
the time soreness develops. Muscle soreness results from an immediate
mechanical injury and a biochemical injury occurring a few days after the
workout (Faulkner et al. 1993). The mechanical injury is caused when the myosin
heads pull away from the actin filament, causing microtears in the muscle
fibers. The biochemical injury is characterized by increased plasma enzyme
activity and a leaking of enzymes (e.g., creatine kinase) out of the muscle.
Soreness typically increases in intensity during the first 24 hours
postexercise, peaks in the next 48 hours, then subsides within five to seven
days after the workout.
Following
eccentric exercise, both ROM and muscular force production decrease (Balnave
& Thompson 1993; Donnelly et al. 1992; MacIntyre et al. 1996; Mair et al.
1995; Newham et al. 1987; Weber et al. 1994). Structural damage, altered neural
activation and a disruption in calcium ion homeostasis are possible reasons for
the decrease in force production that occurs with DOMS (Armstrong 1984). DOMS
is not associated with any long-term damage or reduced muscle function.
As
your clients adapt to the training load, their muscles will be less sore
following a workout. Eccentric training also reduces DOMS (Balnave &
Thompson 1993; Mair et al. 1995).
9. How Do I Get Rid of These Flabby
Arms?
One
of the biggest exercise myths is that you can lose fat in an area of the body
by strength training or exercising that specific body part. The truth is that
“spot reducing” and “spot toning” do not work, because we cannot dictate from
where our bodies will decide to oxidize fat, nor can we change fat into muscle.
Doing triceps press-downs will not decrease the amount of fat clients have on
the backs of their arms any more than doing crunches will decrease the amount
of fat clients have on their stomachs.
As
your clients age, their skin will become less elastic and thus conform less to
their arms. So “flabby arms” are somewhat a product of age. Any exercise that
decreases body fat percentage will help your clients lose fat on their arms,
just as it will help them lose fat from other areas of the body.
10. How Often Should I Work Out/Lift
Weights?
According
to the American College of Sports Medicine (ACSM), your clients should exercise
20 to 60 minutes, three to five days a week for health/fitness promotion (ACSM
1995). Exercising only three days a week may be enough for previously sedentary
clients to improve their fitness, but it will take more exercise to see further
improvements. Improvements in aerobic power (VO2 max),
cholesterol levels, body composition and cardiovascular health are all
augmented the more often you exercise (Duncan et al. 1991; Gettman et al. 1976;
Milesis et al. 1976). However, it is important that your clients do not progress
too soon or exercise excessively, since both these behaviors can lead to
overuse injuries.
Clients
are often told they should not lift weights on consecutive days, whereas they
are encouraged to do cardiovascular exercise as often as they can. However, there
is nothing wrong with lifting weights every day, just as there is nothing wrong
with running every day. Muscles do not know the difference between lifting
weights or running; the only thing muscles know how to do is to contract to
overcome a resistance. Whether your clients need to lift weights every day
depends on their fitness goals. For basic gains in strength, your clients need
to lift weights only two to three times a week. For more advanced clients,
lifting weights more often is fine, and the training program can be organized
using easy and hard days, just as with cardiovascular workouts. Keep in mind
that some experts recommend not working the same muscle groups two days in
succession, in order to give the muscles time to adapt.
