Curves has been operating closely with our customers, supporting their health from various angles in order to solve their health issues. We will continue to contribute to society as a “community-based health infrastructure” and “an enterprise pursuing longer healthy life expectancy”, and will continue to work to support the healthy and fulfilling lives of growing number of people.

No. 1 for 9 consecutive years in the Japanese Customer Satisfaction Index (JCSI) survey (the fitness club segment)

In the Japanese Customer Satisfaction Index (JCSI) survey (the fitness club segment) conducted by the Service Industry Productivity Council, Curves was surveyed for the first time in 2014, and has achieved No. 1 ranked customer satisfaction for nine consecutive years since until 2023. In the same survey, we are the first operator ever in the fitness club industry to be ranked No. 1 for more than nine years in a row.

Medical and scientific evidence of the Curves exercise program

Based on the concept of evidence-based exercise (scientifically proven exercise), Curves has been scientifically demonstrating the effectiveness of the Curves exercise program through joint research with universities and research institutes. In principle, in joint research, we use scientifically effective methodologies such as RCTs (randomized controlled trials), and we ensure the research results have a high level of evidence as peer-reviewed papers.
The main research results include:

[1] Results of joint research with the National Institutes of Biomedical Innovation, Health and Nutrition (the 1st stage)

"Influence of circuit-type combined training on various physical functions for middle-aged women" presented at the September 2008 Japanese Society of Physical Fitness and Sports Medicine.

〈Summary of Evidence presented〉

1. Suggested that it is an effective method for preventing lifestyle-related diseases -
   Arterial stiffness has significantly decreased (-44mm/s: baPWM). Waist circumference (-1.2 cm), systolic blood pressure (-4.1 mmHg), and fasting blood glucose (-6 mg/dl) showed tendency of decrease.
2. Significant reduction in body weight and body fat mass while maintaining lean body mass -
   Body weight (-1.0 kg) and body fat mass (-1.4 kg: DXA method) showed significant decreases. It should be noted that lean body mass was maintained despite significant decreases in body weight and body fat mass.
   Weight loss through aerobic exercise or dietary restrictions would lead to a decline in physical strength, which is not considered healthy weight loss.
3. Significant increase in leg extension power (+33%) -
   Leg extension power showed a significant increase (+33%), and sitting forward bending showed a tendency of increase (+2.2 cm). Maintaining leg muscle strength that supports body weight and flexibility that supports stride length are important physical fitness factors to reduce the risk of falling.

[2] Results of joint research with the National Institutes of Biomedical Innovation, Health and Nutrition (the 2nd stage)

Adopted for the Journal of Diabetes Investigation (JDI) published by the Asian Diabetes Society, and early released on the JDI website on December 18, 2018
J Diabetes Investig. 2018 Dec 18. doi: 10.1111/jdi.12973. PMID: 30561143.
Combined aerobic and resistance training, and incidence of diabetes: A retrospective cohort study in Japanese older women. Sawada SS, Gando Y, Kawakami R, Blair SN, Lee IM, Tamura Y, Tsuda H, Saito H, Miyachi M.

〈Summary of evidence presented〉

In Japanese middle-aged and elderly women, the higher the frequency of circuit training, the higher the preventive effect of the risk of Type 2 diabetes. Circuit training can likely be considered an effective primary prevention measure.

[3] Results of joint research with the Institute of Aging and Cancer, Tohoku University (the 1st stage)

Adopted for AGE published by the American Aging Association and published in April 2014.
Four weeks of combination exercise training improved executive functions, episodic memory, and processing speed in healthy elderly people: evidence from a randomized controlled trial.Nouchi R, Taki Y, Takeuchi H, Sekiguchi A, Hashizume H, Nozawa T,Nouchi H, Kawashima R.

〈Summary of evidence presented〉

Four Weeks of Circuit Exercise Training improves broad cognitive function in elderly Adults
- Expected to be applied to dementia prevention and cognitive function rehabilitation -

1. Improved executive function (abilities of patience and coping with abrupt changes)
2. Improved episodic memory (the ability to remember and recall)
3. Improved processing speed (ability to do numerous tasks in a limited amount of time)

[4] Results of joint research with the Institute of Aging and Cancer, Tohoku University (the 2nd stage)

Published in the online magazine Frontiers in Aging Neuroscience on June 24, 2020
Nouchi, R., Nouchi, H., & Kawashima, R. （2020）. A single 30 minutes bout of combination physical exercises improved inhibition and vigor-mood in middleaged and older females: Evidence from a randomized controlled trial. Frontiers in Aging Neuroscience. 12:179. doi: 10.3389/fnagi.2020.00179

〈Summary of evidence presented〉

A single session of 30 minutes of circuit training results in immediate improvements in cognitive function (inhibition ability) and vitality.
・Cognitive function tends to decline with aging, and the decline in inhibition ability makes it challenging to control emotions and behaviors, causing difficulties in daily life.
⇒ The results of this verification showed that just one session of 30-minute circuit training immediately improves cognitive function (inhibition ability) and vitality leading to a positive mood. This is also considered a notable result for Japan that has entered the super-aging society.
⇒ It is considered very important under the COVID pandemic to maintain good human relations by controlling emotions not to allow trivial things to irritate people, and to be positive and enjoy every day life.

[5] Results of joint research with Tokyo Metropolitan Institute of Gerontology

Adopted by the academic journal, Physical Fitness Sciences, published by the Japanese Society of Physical Fitness and Sports Medicine in June 2015
Shuichi Obuchi, Hisashi Kawai, Seigo Mitsutake, Saori Anzai, Tomohiro Inomata, Hikaru Saito, Hitomi Tsuda, Tomoharu Nakajima:
Effect of circuit-type combined training on daily activity in the elderly,
Physical Fitness Science, 64 (3):305-314(2015)

〈Summary of evidence presented〉

1. Significant improvement in physical activity
   The average number of steps showed a significant increase (+859 steps). The average number of steps taken in the control group decreased (-247 steps).
2. Significant improvement in cardiopulmonary function (aerobic capacity) - 6-minute walk showed a significant increase in distance (+57.8m).

[6] Results of joint research with Kuno Laboratory, Graduate School of Tsukuba

Presented at the 69th Annual Meeting of the Japanese Society of Physical Fitness and Sports Medicine in September 2014 - "Effects of short-term circuit exercise on muscle mass, muscle strength, and walking ability in middle-aged and elderly women"
Eunji BANG 1), Kai Tanabe 1), Shin Ching Wang 1), Hitomi Tsuda 2), Hikaru Saito 2), Naomi Saito 3), Shinya Kuno 1)
1) Graduate School of Comprehensive Human Sciences, University of Tsukuba, 2) Curves Japan, 3) Tsukuba Wellness Research

〈Summary of evidence presented〉

1. Curves exercise program significantly increased muscle mass compared to 6 months of aerobic exercise.
   The cross-sectional area of the psoas major muscle increased significantly (7.1%) compared to the walking group (1.4%). The thigh muscle cross-sectional area increased significantly before and after the intervention.
2. Significant increase in muscle strength compared to aerobic exercise.
   There was a significant difference in isokinetic knee joint flexion muscle strength (angular velocity 60°/sec) and hip joint flexion muscle strength (angular velocity 60°/sec) compared to the walking group (increase of 7.5% and 23.6%, respectively).
3. Compared to aerobic exercise, thigh subcutaneous fat area significantly decreased.
   A significant decrease (-6.5%) was shown in the thigh subcutaneous fat area compared to the walking group (-1.8%). Therefore, by continuing the Curves exercise program for a long period of time, it is considered that the loss of muscle mass due to aging of approximately 3 to 9 years can be prevented, leading to the prevention of sarcopenia, which causes the need for long-term care.

[7] Results of joint research with Osaka University Graduate School of Medicine and Eli Lilly Japan

Results published in Scientific Reports in July 2021.
Seira Sato, Sho Ukimoto et al., Chronic musculoskeletal pain, catastrophizing, and physical function in adult women were improved after 3-month aerobic-resistance circuit training, Sci Rep. 2021 Jul 22;11（1）:14939.

〈Summary of evidence presented〉

Participants who continued 30-minute circuit training for 3 months showed improvement in chronic musculoskeletal pain (CMP). In particular, participation in exercise more than twice a week improves catastrophic thinking and lower back and knee function, and is expected to be clinically useful as efficient exercise.

Support and active participation in research that contributes to solving health problems in Japan

In order to contribute to the resolution of social issues, we support and actively participate in various research studies that would lead to the resolution of health issues such as the realization of a society with healthy and long-lived life.

The main activities include:

[1] Sponsorship and participation in the R&D Center for Smart Wellness City Policies University of Tsukuba

The R&D Center for Smart Wellness City Policies University of Tsukuba was established by the University of Tsukuba in 2020 with the purposes of contributing to the creation of a city that can realize a society with healthy and long-lived life, promoting development and research on various issues caused by the super-aging society, proposing appropriate policies as well as establishing a training function for highly skilled professionals who can achieve these goals. Curves agrees with the purposes of the center, sponsors the center, and actively participates in research activities.

[2] Sponsorship and Participation in the Juntendo University Sportology Center Bunkyo Health Study

In 2007, the Sportology Center was selected for the high-tech research center development project by the Ministry of Education, Culture, Sports, Science & Technology and established by Juntendo University with the aim of promoting a new academic field that fuses medicine and sports and aiming to build evidence for preventive medicine for extending healthy life expectancy. The Bunkyo Health Study is an academic study through the health follow-up surveys of elderly people living in Bunkyo Ward, Tokyo, promoted by the Sportology Center for the purpose of developing future preventive care methods. Curves in agreeing with the purpose of the center sponsors the center and its research, as well as participates in research activities.

[3] Participated as one of the founders of the Smart Wellness Community (SWC) Council

The SWC Council was established in 2015 as an organization that gathers a wide range of wisdom from industry, government, and academia to solve problems, focusing not only on traditional health and medical approaches, but also on various aspects such as urban development and sports. As one of the founders of this council, Curves plays a central role in the activities of "Health Ambassadors" (health evangelists) who convey correct health knowledge to the "people indifferent on health", which accounts for about 70% of the population.

[4] Research support for the FY2023 National Strategic Innovation Promotion Program, "Building an Inclusive Community Platform"

The Strategic Innovation Promotion Program (SIP) is a government program established for the realization of science and technology innovations by the Cabinet Office's Council for Science, Technology and Innovation, acting as a control tower to manage across the boundaries of Ministries and traditional barriers. Curves is providing research support for research themes to be taken up in "Building an inclusive community platform," which is one of the expected agendas of the Strategic Innovation Creation Program scheduled to be implemented from FY2023 (next phase of SIP).