A Step-by-step Approach to Helping Your Clients Successfully Lose Weight and Tone Up

By Pete McCall, M.S.

It doesn’t take long for a newly certified personal trainer to learn that one of the most commonly stated client goals is to “lose weight and tone up.” Many people starting an exercise program have the perception that the ultimate goal is to achieve a defined physique with rippling muscles, an idea reinforced by television infomercials and many top-selling fitness DVDs. Titles like 30-day Shred, Ripped in 30 and Extreme Shed and Shred make it seem like building a beautiful body can be achieved in a few simple steps or in a limited amount of time. Of course, there are no easy solutions for getting results from exercise, especially when it comes to losing weight and adding lean muscle. It is possible, however, to help your clients achieve their goals, if you create safe, well-designed programs based on the scientific principles presented here.

What Does Losing Weight and Toning Up Really Mean?

You are faced with two specific challenges when a client says that “losing weight and toning up” are his or her primary fitness goals. The first challenge is to identify exactly what your client really means by “losing weight and toning up.” This could mean anything from wanting to lose weight gained during a recent pregnancy, to a desire to return to a teenage physique before an upcoming high school reunion, to a quest to lose weight to please a spouse who has threatened divorce (all real-life examples). Identifying the client’s interpretation of “losing weight and toning up” requires asking him or her probing questions to gain a deeper understanding of the purpose for beginning an exercise program. Questions to help clarify the objective and identify specific reasons for the goal can include:

• “What exactly do you mean by ‘losing weight and toning up’? What does ‘toning up’ mean to you…could you please elaborate? How much weight do you want to lose—can you provide a specific amount?” 
• “Why is this goal important? How long have you wanted to achieve this goal?”
• “Are you committed to this goal? What steps are you willing to take to take to reach this goal?” 

Using light weights for high repetitions WILL NOT develop muscle tone.

Once a specific reason for the goal is identified, it becomes the primary motivational tool to keep the client engaged with the exercise program.

The second challenge you face in helping a client tone up and lose weight is to dispel some common fitness myths and educate the client on the steps required to achieve his or her goal. The first myth is that “toning up” is achieved with light weights and high repetitions. That's right: Using light weights for high repetitions WILL NOT develop muscle tone. The term “tone” comes from the word tonus, a technical term used to denote a state of constant muscle tension or contraction. Since a contraction creates the shape or definition of a muscle, over time the term tone became synonymous with muscular definition. 

Muscle Physiology 

Training to enhance muscular definition requires a deeper understanding of muscle-fiber physiology. There are two basic muscle-fiber classifications: type I (slow-twitch) and type II (fast-twitch). Slow-twitch muscle fibers are also known as aerobic muscle fibers due to their ability to create energy from oxygen, which allows them to sustain a contraction over an extended period of time. For this reason, most muscles responsible for producing and maintaining good posture are comprised of type I fibers and are often referred to as tonic stabilizers. Type I muscle fibers are activated by type I motor units (a motor unit is the motor neuron and the muscle fibers it attaches to), which have a low activation threshold. This means it does not take much force to cause type I muscle fibers to contract. When a muscle is required to generate a force, type I motor units and muscle fibers are the first recruited; once they fatigue, other motor units and muscle fibers are called into action.

There also are different classifications of type II (fast-twitch) muscle fibers: type IIb, which produce energy without the presence of oxygen (anaerobic), and type IIa, which, depending on the training stimulus, take on characteristics of either type I or type IIb fibers. Both classifications of type II muscle fibers are responsible for creating higher levels of force to produce human movement and are known as phasic muscles.

Type II muscle fibers are activated (innervated) by specific type II motor units, which have a higher activation threshold. This means they are only activated when a large amount of force is required. In addition to being responsible for producing the force necessary for dynamic movements, type II muscle fibers have a greater diameter (cross-width) than type I fibers and are responsible for the hypertrophy, or increased fiber size, of a particular muscle.

If an individual has a fitness goal involving “toning up” or enhanced muscle definition, the only way to achieve this is by activating the type II motor units and muscle fibers responsible for hypertrophy and definition. There are two ways to do this, both of which both involve increased levels of force production. A muscle has a finite number of motor units; however, the higher-threshold type II motor units (and attached muscle fibers) are not “turned on” unless a high level of force is needed for a particular action. The most common way to increase motor unit activation is by lifting heavier weights; an increased load placed on a muscle will cause a greater number of motor units to respond in an effort to innervate more fibers to generate a muscular force to overcome the resistance. If an individual lifts a heavier weight for the first time, he or she will notice that the muscles involved begin to shake. This is caused by the recruitment and stimulation of previously dormant motor units and muscle fibers.  

Strength Training

It is a common misperception that lifting heavier loads automatically creates bigger muscles. The standard protocol for resistance training to achieve hypertrophy requires performing eight to 12 repetitions of a given exercise (fatiguing by the last repetition), moderate-duration rest intervals of 60 to 120 seconds, for three to four sets. This type of training will stimulate what is known as sarcoplasmic hypertrophy—enhanced muscle size due to an increase in the volume of the sarcoplasm between individual muscle fibers. The muscle “pump” that body-builders work to achieve is actually sarcoplasmic hypertrophy—the cross-section of muscle fibers will increase, but most of the enhanced muscle size is due to an increased volume of the sarcoplasm and non-contractile proteins not directly involved with force production. Following the resistance-training guidelines for hypertrophy will result in enhanced muscle size, which some clients might appreciate. However, for those clients who are interested in muscle definition without a significant increase in muscle size, it is necessary to follow a different set of protocols designed to develop a second type of hypertrophy.

Myofibrillar hypertrophy is an increase in muscle fiber size due to enlargement of myofibrils (individual muscle fibers), which are comprised of the actin and myosin protein filaments responsible for generating a muscle contraction. Resistance training with heavier loads stimulates production of the anabolic hormones testosterone (T), growth hormone (GH) and insulin-like growth factor (IGF-1), all of which assist with muscle protein synthesis, the repair process of muscle tissue after a training session. A common concern among many female clients is that resistance training will automatically result in larger muscles, but this fear is unfounded. Myofibrillar hypertrophy does not lead to larger muscles; rather, it results in thicker muscle fibers capable of generating more force, as well as an enhanced appearance of muscle definition. 

Properly recruiting and stimulating a type II muscle fiber requires creating enough overload to fatigue the involved muscle by the end of the set. Training for myofibrillar hypertrophy requires following the protocols for maximum strength training: 

• compound exercises involving multiple muscle groups 
• two to six repetitions (fatiguing by the last repetition)
• rest intervals of 30 seconds to three minutes (shorter rest intervals would be used when circuit-training or alternating body parts, while longer intervals would be required when performing supersets) 
• two to four sets per exercise 

Table 1 features a sample myofibrillar hypertrophy training program. 

In a comprehensive literature review on training for muscle hypertrophy, researcher Brad Schoenfeld (2010) writes: “The use of high repetitions has generally proven to be inferior to moderate and lower repetition ranges in eliciting increases in muscle hypertrophy…a load of less than approximately 65 percent of one-repetition maximum [1 RM] is not considered substantial…the load is inadequate to recruit and fatigue the highest threshold motor units.” 

Power Training

The second method for stimulating type II motor units and muscle fibers is through explosive, high-velocity movements involving a rapid lengthening and shortening of the involved muscles. Commonly referred to as power training, increasing the rate of muscle lengthening and minimizing the transition time from the eccentric phase to the concentric shortening action will activate more muscle spindles which, in turn, activate more muscle motor units. Dynamic, power-based movements are, by definition, explosive and use primarily type IIb muscle fibers because of the requirement for immediate energy from anaerobic sources. Exercises to maximize the power output of a muscle include jumps, medicine-ball throws and explosive barbell lifts such as the snatch or clean-and-jerk.

Power training is not only an effective way to activate high-threshold, type II motor units, but is also an extremely efficient method of burning calories during a training session. Power is defined as the time period to perform work: P = W/T; work is the product of Force X Distance (W = FD), where Force = Mass x Acceleration (F = MA). The time period of a personal-training session is generally fixed at one hour; therefore, improving power output (work-rate) and type II muscle fiber activation requires changing one of three inputs: 

1. Using a greater mass (heavier weight)

2. Increasing the rate of acceleration of the weights lifted (throws and explosive movements) 

3. Increasing the distance traveled during a training session 

The end result of power training is that a client will activate more type II muscle fibers, which will result in improved muscular definition. Consider, for example, athletes who run 100- or 200-meter sprints. The training for sprinting requires explosive, power-based exercises, which leads to increased recruitment and activation of type II fibers and results in lean, muscular physiques.

To help clients achieve the goal of “toning up,” follow the ACE Integrated Fitness Training^® (ACE IFT^®) Model of exercise program design. The overload to stimulate the hard-to-activate type II muscle fibers can be created by either using heavier resistance during the Load phase of the ACE IFT Model, or by incorporating the explosive muscle actions of power training in the Performance phase. Starting a client in the Stability and Mobility phase of the ACE IFT Model helps to ensure the proper core stability and distal mobility necessary to improve movement efficiency in the Movement phase of training. These initial phases allow a client to improve core stability, distal mobility and coordination before progressing to the high-intensity strength training of the Load phase or the dynamic power training of the Performance phase. Taking the time to progress a client through the foundational stages of the ACE IFT Model greatly increases the chance for optimal results once he or she reaches the Load or Performance phases. During the Load training phase, if a client can do more than the assigned number of repetitions, then he or she is simply not using enough resistance to stimulate the desired muscle fibers and will need to add resistance to stay within the optimal repetition range for myofibrillar hypertrophy. 

An exercise program for power training should include an extensive warm-up with exercises from the Stability and Mobility and Movement phases of the ACE IFT Model. Exercise selection for power training may include total-body exercises such as power cleans, or it may focus on body-part specific exercises such as jumps and medicine-ball chest passes. The intensity can be anywhere from 50% 1 RM for exercises requiring multiple repetitions to 100% 1 RM for an exercise focused on a single effort. Explosive, power-based exercises during the Performance phase should be limited to no more than six or eight repetitions to ensure optimal safety and reduce the risk of injury. The goal of power training is to generate as much force you can, as quickly as possible; therefore, the rule for power training is that whenever force output drops by 10 percent, that particular set is complete. The length of the rest interval (i.e., 30 seconds to three minutes) depends on whether the exercises alternate from muscle group to muscle group, thus requiring shorter rest intervals, or are for the same muscle group, which requires a longer rest interval to ensure adequate recovery. The number of sets can vary from three to five, depending on the intensity and duration of the training program and, most importantly, the experience and work capacity of the client. 

Table 2 features a sample program for power training. 

Cardiorespiratory Training for Weight Loss 

While resistance training in the Load and Power phases of the ACE IFT Model will burn calories and help a client to lose weight while “toning up,” it is also important to include cardiorespiratory exercise for additional energy expenditure. New or inexperienced personal-training clients may share some common misperceptions related to cardiorespiratory training, such as the belief that lower-intensity cardiovascular exercise is more effective for fat burning. Interestingly, another common misperception is that the most effective way to burn calories is to perform high-intensity cardio exercise for extended periods of time. While there is some truth to each of these beliefs, it is important to have a solid understanding of how to apply cardiorespiratory training and energy metabolism to help your clients lose weight both safely and effectively. 

Aerobic Base, Aerobic Efficiency, Anaerobic Endurance and Anaerobic Power are the four stages of the ACE IFT Model for cardiorespiratory training and, with the exception of the Aerobic Base stage, are based on identifying an individual’s heart rate at specific metabolic markers. The first ventilatory threshold (VT1) indicates the point where the body starts converting energy from carbohydrate instead of free fatty acids. This is the half-truth behind the fat-burning zone: It is easier for the body to convert fat to fuel and expend more fat for energy at lower exercise intensities. However, stimulating significant weight loss necessitates expending more net energy, which requires working at intensities above VT1. If a client continues to train in the fat-burning zone (below VT1), he or she is unlikely to expend enough energy to significantly impact weight loss. 

Aerobic Base

The intent of the first phase of the ACE IFT Model for cardiorespiratory training—Aerobic Base—is to help clients adopt healthier behaviors by performing cardiorespiratory exercise they are capable of doing through the application of a walking program or other low-intensity aerobic exercise. Lower-intensity activities help a beginner develop self-confidence through a pattern of healthy behaviors before progressing to the higher-intensity exercises that will ultimately provide the results. 

Aerobic Efficiency

The second phase of the ACE IFT Model—Aerobic Efficiency—requires the application of the Talk Test to identify the heart rate at VT1. Once you have identified your client’s first ventilatory threshold, you can design an aerobic exercise program for him or her based on two specific zones: above and below VT1. If a client does not have access to a heart-rate monitor, a simple method of determining intensity is to monitor how difficult it is to talk. If a client can speak comfortably, then he or she is working below VT1 and metabolizing fat as the primary source of fuel. However, if a client is exercising at an intensity above VT1, talking can be somewhat to moderately difficult, which is an indication that the body has started metabolizing carbohydrates as the primary source of muscle fuel. Steady-state training near VT1 and interval training where the work intervals are above VT1 and the recovery intervals are below are both effective for improving an individual’s aerobic capacity. Developing and implementing a two-zone model in the Aerobic Efficiency phase lays the foundation for helping your client burn more calories by gradually progressing exercise intensity.

Table 3 presents a sample two-zone interval workout for runners.

Without question, higher-intensity exercise expends more calories per minute. However, cardiorespiratory training at a challenging-to-difficult pace for an extended period of time can actually be inefficient; rather than burning calories from fat it can lead to the loss of muscle protein. It is not uncommon for an individual to begin an exercise program with the intention of losing weight by performing a high volume of cardiorespiratory training at a high intensity, typically above VT1. This approach, however, will cause the body to utilize all available muscle glycogen. When glycogen is no longer available as an energy source, the hormone cortisol initiates a process called gluconeogenesis, which stimulates the liver to convert protein into glycogen to continue to fuel activity. When protein is used as a source of fuel, it is not available for protein resynthesis and tissue repair. If the same individual starts restricting calories and does not take in adequate post-training nutrition to support muscle recovery, he or she is creating a situation where the body will catabolize muscle protein. This means that, rather than losing body fat, much of the weight loss that does occur could instead be the result of losing lean muscle. 

Anaerobic Endurance

To help clients avoid this situation and to stimulate desired weight loss from body fat, it is important to follow the progressions of the ACE IFT Model for cardiorespiratory training and gradually increase the intensity of exercise to phase 3: Anaerobic Endurance. Designing an effective Anaerobic Endurance training program requires performing a field test to identify your client’s heart rate at the onset of blood lactate (OBLA), also known as the second ventilatory threshold (VT2). Once VT2 is identified, a three-zone training program can be created that allows clients to perform work anaerobically above VT1 or VT2 and to recover aerobically below VT1. 

HIIT–induced metabolic stress is an effective approach to developing lean muscle; Schoenfeld (2010) states that “a large body of evidence shows that it [metabolic stress] can have a significant hypertrophic effect.” The short bursts of intense, anaerobic activity above VT2 followed by aerobic-based recovery below VT1 that characterize HIIT has been proven effective for burning calories while also improving aerobic capacity. An appropriate work-to-recovery ratio for HIIT training above VT2 would be 1:2–4 (e.g., 10 seconds of high-intensity work followed by 20 to 40 seconds of lower-intensity active recovery). Longer recovery periods are recommended when introducing a client to HIIT programming. As the client adapts to the high-intensity work rate and his or her ability to recover improves, the time period for active recovery can be shortened. Using HIIT for running reduces the risk of developing repetitive stress injuries that may occur from high-volume training (Table 4).  

Like heavy resistance training, HIIT stimulates an increased production of the anabolic hormones T, GH and IGF-1, which are responsible for muscle growth and fat metabolism. Research by Linnam and colleagues (2005) indicated that “hormonal changes appear to be related to the amount of muscle mass activated and to the metabolic response caused by the exercise.” Likewise, in their research on sprint interval training, Meckel et al. (2011) found that to stimulate an anabolic response, “input should be sufficient to cause a sizable metabolic effect.” Intense exercise does produce the results many clients want. However, to reduce the risk of an overuse injury it is important to take the time to properly progress a client to high-intensity training and to implement a program with periods of lower-intensity exercise to allow for the proper recovery and adaptation to the training stimulus.

Conclusion 

Studying exercise physiology can sometimes be dry and dull; however, it is critical for all fitness professionals to be able to apply exercise science to real-world situations. Whether it is with heavy-resistance training, explosive power exercises or HIIT, exercising with enough intensity to stimulate anabolic hormone production is the “secret sauce” to helping clients achieve weight loss and muscle definition. That is the benefit of understanding how to apply the ACE IFT Model; the progressions are based on how human physiology adapts to exercise. At some point in your career, you will undoubtedly hear a client express a desire to “lose weight and tone up” as his or her motivation for starting an exercise program. Having the specific knowledge of what this really means and how to apply the ACE IFT Model to safely progress exercise intensity to the point of stimulating the appropriate metabolic response will make it possible for you to help your clients achieve their goals.  

References and Recommended Reading

Crewther, B. et al. (2006). Possible stimuli for strength and power adaptation. Sports Medicine, 36, 3, 215–238.

Knapik, J. et al. (2009). Training: Rationale and evaluation of the physical training doctrine. Journal of Strength and Conditioning Research, 23, 4, 1353–1362. 

Kraemer, W. and Ratamess, N. (2005). Hormonal responses and adaptations to resistance exercise and training. Sports Medicine, 35, 4, 339–361.

Linnam, V. et al. (2005). Acute hormonal responses to submaximal and maximal heavy resistance and explosive exercises in men and women. Journal of Strength and Conditioning Research, 19, 3, 566–571.

Meckel, Y. et al. (2011). Hormonal and inflammatory responses to different types of sprint interval training. Journal of Strength and Conditioning Research, 25, 8, 2161–2169. 

Schoenfeld, B. (2010). The mechanisms of muscle hypertrophy and their application to resistance training. Journal of Strength and Conditioning Research, 24, 10, 2857–2872. 

Tan, B. (1999). Manipulating resistance training program variables to optimize maximum strength in men: A review. Journal of Strength and Conditioning Research, 13, 3, 289–304.

Vingren, J., et al. (2010). Testosterone physiology in resistance exercise and training. Sport Medicine, 40, 12, 1037–1053.

Zatsiorsky, V. and Kraemer, W. (2006). Science and Practice of Strength Training (2nd ed.). Champaign, Ill.: Human Kinetics.

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Pete McCall, M.S., an Exercise Physiologist with ACE, creates and delivers fitness education programs to uphold ACE’s mission of enriching quality of life through safe and effective exercise. He has a master's degree in Exercise Science and Health Promotion. In addition, he is an ACE-certified Personal Trainer and holds additional certifications and advanced specializations through NSCA and NASM. McCall has been featured in The Washington Post, The New York Times, Los Angeles Times, Runner’s World and Self.