The Effects of Combined Training on Strength and Aerobic Power in Patients with Cancer

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JEPonline

The Effects of Combined Training on Strength and Aerobic Power in Patients with Cancer

Bruno P. Melo1, Francisco A. Manoel1, Ramon Cruz2, Sandro F. da Silva3

1Postgraduation student in Physical Education, Estadual University of Maringá, Maringá/PR Brazil 2Postgraduation student in Physical Education, Federal University of Juiz de Fora, Juiz de Fora/MG Brazil, 3Adjunct Professor at Federal University of Lavras, Lavras/MG Brazil

ABSTRACT

Melo BP, Manoel FA, Cruz R, da Silva SF. The Effects of Combined Training on Strength and Aerobic Power in Patients with Cancer. JEPonline 2015;18(4):10-16. Although exercise is considered an effective strategy for mitigating problems caused by cancer, little is known about the effects of combined training (CT) in cancer patients. Six men (68.94 ± 11.79 yrs old, 66.68 ± 7.36 kg, 167 ± 8.02 cm) and 6 women (64.07 ± 11.46 yrs old, 74.70 ± 12.89 kg; 160 ± 10.01 cm) with cancer were subjected to 20 wks of CT (3 d·wk-1). Each session consisted of 40 min of aerobic exercise (60 to 70%) of maximum heart rate and 3 sets of 12 to 15 repetitions at 50 to 60% of 1RM. The VO2 max was estimated by the 1 Mile Walk Test and strength was estimated through 1RM prediction. The Student t-test was used to identify differences between each assessment. Cohen’s D criterion was used to calculate the effect size of the variables in the two moments, adopting the significance level of P<0.05. The results indicated that there was a significant increase (P0.05) in strength in the following exercises: chair abductor (58.40 ± 11.90 vs. 73.05 ± 15.00); shoulder press (10.22 ± 5.30 vs. 17.63 ± 6.21); back lat pulldown (21.06 ± 4.99 vs. 27.36 ± 7.60); and peck-deck (32.91 ± 11.11 vs. 46.80 ± 14.58). There was no statistically significant change in VO2 max. Therefore, while the combined training resulted in an improvement in strength, it did not improve the cancer patients’ aerobic capacity.

Key Words: Functional Capacity, Training, Exercise Physiology, Special Populations

INTRODUCTION

Understanding and having some control over malignant diseases requires scientific knowledge and experiences that go from the awareness of complex intracellular molecular regulation mechanisms to making individual lifestyle choices (6). Due to its prevalence and harmful effects, cancer represents a major public health issue worldwide.

While radiotherapy and chemotherapy are commonly administered in several types of cancer (1), the treatments often lead to significant side effects that result in diminished physical and psychological capacities in the patients (13). Many of the effects are fatigue, depression, decreased strength, and reduced quality of life after treatment begins and some adverse effects continue long term (2).

Hence, instead of dealing the side effects of undergoing radiotherapy and chemotherapy (18), regular exercise has been demonstrated to have great health benefits for patients with cancer. This is the case even though clients benefit from aerobic and resistance exercises at different intensities and duration of effort (1,10). In fact, Fong and colleagues (9) and McClellan (15) demonstrated that exercise programs for patients who had completed radiotherapy and chemotherapy treatments led to the improvement in maximal oxygen uptake and distance covered in 6 min. Body weight, fatigue, and depression were decreased.

Corroborating these findings, Keogh and MacLeod (11) observed that physical training throughout a 13-wk program improved aerobic endurance and the overall quality of life of the cancer patients. Lee et al. (14) also demonstrated that patients who exercised regularly had lower rates of mortality that were associated with cancer and cardiovascular diseases.

The purpose of this study was to: (a) identify the effects of the aerobic training combined with strength training when performed under moderate intensity of cancer patients who underwent radiotherapy and chemotherapy; and (b) determine whether the combined training leads to long term positive effect in cancer patients.

METHODS

Subjects

Six men with prostate cancer and six women with breast cancer participated in this study. All subjects signed the Free and Informed Consent Form that was approved by the Ethics Committee of the University of Itaúna under protocol n. 017/10. The sample characteristics are presented in Table 1.

Table 1. Descriptive Data of the Subjects.

Procedures

All the subjects underwent diagnostic evaluation of anamnesis, anthropometric evaluation, muscle strength, and aerobic capacity. The subjects underwent an afternoon of physical training that combined aerobic and strength activities performed 3 times·wk-1 on alternate days, with mean duration of 90 min for 20 wks (60 training sessions). Training intensity was individually prescribed according to outcomes obtained during the diagnostic evaluation. The exercise room at the Human Movement Studies Laboratory was specifically designed for research and extension projects. Aerobic power and muscle strength evaluations were performed before and after the 20 wks program of combined training.

Maximal strength of the upper (SUL) and lower limbs (SLL) was evaluated by means of resistance machines and free weights used to perform the following exercises: (a) SUL = peck-deck (fly), shoulder press (shoulder), barbell curls (biceps), and triceps pushdown; and (b) SLL = leg curl machine, knee extension chair, chair adductor, and chair abductor.

Strength training emphasized exercises for different muscle groups that consisted of performing 3 sets of 12 to 15 repetitions with an intensity of 50 to 60% of 1RM. At the end of each set, the Rating of Perceived Exertion (RPE) was determined for each subject following the 0 to 10 point scale of exercise resistance (16) during the entire training period. For estimating maximal strength in each exercise, the subject performed about 8 to 12 repetitions. Subsequently, the equation by Brzycki (5) was used to estimate 1RM. Subjects were evaluated every 15 training sessions in order to adjust the training load and to monitor the intensity of the exercises.

The prediction of maximum oxygen consumption (VO2 max) was performed by the 1 Mile Walk Test (12), during which the subjects walked 1609 m as fast as possible without trotting or running. The evaluation was performed on a running track. Each 100 m of the route was marked for HR collection, which was done by means of a Polar® (RS800cx) heart rate monitor and the RPE was done for each subject.

Aerobic training was conducted on a treadmill and on a running track. Intensity was controlled by heart rate and RPE (4), given the intensity of 60 to 70% of maximum heart rate (HR max) and RPE between 12 to 15 points. Each training session lasted 40 min.

Statistical Analyses

Descriptive statistics with comparison of the mean and standard deviation was used. For the sample distribution, Shapiro-Wilk W-test was applied followed by the Student t-test to identify differences between each assessment. Cohen’s D criterion was used to calculate the effect size of the variables in the two moments. The SPSS 20.0 statistic software was used. Statistical significance was set at an alpha level of P<0.05.

RESULTS

After the subjects participated in the combined training, it was possible to observe that the exercises for the lower limbs showed improvement in strength compared to the diagnostic evaluations. The exercise performed in the chair abductor showed significant difference (P = 0.02) in increasing 1RM strength after completing the training (Table 2).

Table 2. Strength in the Lower Limbs Related to 1RM in Kg.

*Significant difference (P0.05).

Table 3 shows the subjects’ means ± SD of muscle strength related to 1RM for the upper limb exercise. There were significant increases in shoulder press, back lat pulldown, and peck-deck (fly) exercises. The subjects’ before and after responses during the 1 Mile Walk Test are presented in Table 4.

Table 3. Strength in the Upper Limbs Related to 1RM.

*Significant difference (P<0.05).

Table 4. The Subjects’Responses during the Before and After the 1 Mile Walk Test.

*Significant difference (P0.05).

DISCUSSION

Cancer patients frequently experience loss of physical capacity and well-being when treated for their disease. Strength training combined with aerobic exercise training is believed to be an important intervention for cancer patients who undergo radiotherapy and chemotherapy. Prescribed resistance training at an intensity of 50 to 60% of 1RM is well accepted by patients who report no muscle discomfort when performing physical activities.

Except for the non-significant difference in VO2 max after training, the increase in the cancer patients’ muscle strength is in agreement with the work of Adamsen and colleagues (1) and Battaglini et al. (3). The results suggest that emphasis on resistance training should be used to combat fatigue and increase lean muscle mass and strength in cancer patients.

The statistically different strength differences were found predominately in the upper limb muscles. Part of the explanation may be in the exercises that were used in this study. The fact that the patients adapted to the exercises is important, since motor coordination and quality of movement are vital to the success of this intervention in cancer survivors.

Maximum oxygen consumption and strength are important predictive factors for chronic prognosis in cancer patients. Evidences obtained from epidemiological studies indicate that there is an inverse relationship between cancer mortality and lifestyle, which includes aerobic activities in the daily life of patients (6-8,18). Interestingly, after 20 wks of participation in the combined training program, there was no statistically significant improvement in the cancer patients’ performance of the 1 Mile Walk Test. Also, there were no significant differences in HR-average, HR-peak, RPE, average speed, and VO2 max. With regards to the aerobic power, the finding is in disagreement with the study by Vincent et al. (17) who found an improvement of VO2 max of 2.21 mL.kg-1·min-1 with aerobic exercise at 50 to 60% of HR max for 12 wks in women with breast cancer treated with chemotherapy.

CONCLUSIONS

The findings in the present study indicate that combined training did not produce the expected strength and aerobic power benefits to cancer patients who had undergone radiotherapy and chemotherapy. However, aside from the non-significant change in VO2 max in particular, the increase in primarily upper limb muscle strength should lead help minimize the hemodynamic response to daily activities. This factor alone should be viewed as a positive outcome when it comes to increasing the patients’ longevity and quality of life by decreasing fatigue, muscle wasting, and energy loss in cancer survivors.

ACKNOWLEDGMENTS

Financial Support – CAPES – Coordenação de Aperfeiçoamento de Pessoal de Nível Superior

– Scientific Initiation Scholarship.

Address for correspondence: Sandro Fernandes da Silva, PhD, NEMOH - Nucleus of Studies

of Human Movement - Department of Physical Education - University of Lavras - University Campus, PO Box 3037, ZIP Code 37200-000. Lavras/MG.Brasil. 00 55 (35) 3829-5132-

REFERENCES

1.  Adamsen L, Midtgaard J, Rorth M, Borregaard N, Andersen C, Quist M, Knutsen L. Feasibility, physical capacity, and health benefits of a multidimensional exercise program for cancer patients undergoing chemotherapy. Support Care Cancer. 2003;11(11):61-68.

2.  Adamsen L. Effect of a multimodal high intensity exercise intervention in cancer patients undergoing chemotherapy: Randomized controlled trial. British Med J. 2009;13(339):403-410.

3.  Battaglini C, Bottaro M, Dennehy C, Barfoot D, Shields E, Kirk D, Hackney AC. The effects of resistance training on muscular strenght and fatigue levels in breast cancer patients. Rev Bras Med and Sports. 2006;12(3):153-158.

4.  Borg, GA. Psychophysical bases of perceived exertion. Med and Sci Sports Exerc. 1982;14 (5):377-381.

5.  Brzycki M. Strength testing: Predicting a one-rep max from repetitions to fatigue. JOPERD. 1993;68:88-90.