WHY STRENGTH
Every Age Needs Strength. Many People Don't Get Enough.
Health guidelines recommend muscle-strengthening activity at every age, from grade school to retirement. Here is what strength does, how coached training differs from playing a sport or taking PE, and the research behind every line.
3+
days a week of muscle- and bone-strengthening activity are recommended for ages 6 to 17. For adults, 2 or more.
60.6%
of US high school girls reported muscle-strengthening exercise on fewer than 3 days a week in 2025. For all students, 49.4%.
2 in 3
US adults missed the muscle-strengthening guideline in 2024. At 65 and over, 77.8%.
Technique first
Strength for any sport
Competing is optional
SPORT VS. TRAINING
Playing a Sport Isn't the Same as Training for It
Practice and games build skill, fitness and teamwork. Coached strength training targets the strength and movement control a sport demands. Sport and medical groups recommend doing both.
"Participation in organised sports, however, does not ensure a suitable level of integrated strength."
International Olympic Committee consensus statement on youth athletic development (IOC, 2015)
PLAYING THE SPORT
• Builds sport skill, game fitness and teamwork.
• The NSCA says young people are often underprepared for the demands of sport. (NSCA, 2016)
• Early single-sport specialization is linked to more overuse injuries in studies of young athletes. Experts recommend trying several sports, at least until puberty. (Jayanthi, 2015; AAP, 2016)
TRAINING FOR IT
• In trials of young athletes, adding well-designed resistance training to regular practice built more strength than the same practice alone, with smaller gains in jumping and sprinting. (Lesinski, 2016)
• The NSCA says children who are ready for organized sport are ready for developmentally appropriate strength and conditioning. (NSCA, 2016)
• In youth sport trials, neuromuscular training, which mixes strength, jumping, landing and balance work, reduced lower-limb injuries. (Steib, 2017; Emery, 2015)
• In trials of girls and young women in soccer, basketball and handball, programs built on strength and landing practice reduced serious knee (ACL) injuries, more so in younger teens. (Petushek, 2019)
EVERYDAY LIFE
Strength You Use Every Day
Climbing stairs, carrying groceries, getting up off the floor: daily life runs on strength. It declines with age, and strength can be built at every age studied. (Mitchell, 2012; Liu, 2009)
WHAT HAPPENS WITH AGE
• Muscle declines by about 4% of peak mass per decade in one major review, and strength falls two to five times faster. (Mitchell, 2012)
• Everyday tasks take a large share of an older adult's strength. (Hortobágyi, 2003)
WHAT TRAINING CHANGES
• Strength can be built at every age studied, including people in their 90s. (Liu, 2009; Fiatarone, 1990)
• In trials of older adults, resistance training improved strength, chair rising and walking speed. More strength leaves more in reserve for everyday tasks. (Liu, 2009; ACSM, 2026)
• In a trial of postmenopausal women with low bone mass, supervised heavy lifting and impact training improved spine bone density. (Watson, 2018)
• Exercise and Sports Science Australia's osteoporosis position statement: “…bone responds positively to impact activities and high intensity progressive resistance training.” A 2022 UK consensus statement also recommends resistance and impact exercise for people with osteoporosis. If you have osteoporosis or low bone mass, talk to your doctor first. (ESSA, 2017; Brooke-Wavell, 2022)
• In one study, elite Masters weightlifters were stronger and more powerful than untrained people their age, though both declined at a similar rate. (Pearson, 2002)
• Muscle-strengthening activity is linked to lower risk of early death in large studies. Aerobic activity matters too. (Momma, 2022; Zhao, 2020)
Health markers move in trials too. Resistance training lowered HbA1c (a long-term blood sugar measure) in adults with type 2 diabetes, lowered resting blood pressure by a few points on average, and reduced depressive symptoms on average. It does not replace medical care: if you have diabetes, high blood pressure or depression, talk to your doctor before you start. (Wan, 2024; Edwards, 2023; Gordon, 2018)
PE VS. COACHING
PE and Coached Training Do Different Jobs
School PE gives every student movement, games and fitness. Coached strength training focuses on one thing: making each athlete stronger, safely and step by step. We see ourselves as a partner to school PE, not a replacement.
SCHOOL PE
• A required, broad course for every student. California's standards cover movement skills, fitness, fitness concepts, and personal and social skills, and they introduce overload, progression and basic weight training by grade 8. (CDE, 2005)
• California requires at least 200 minutes every 10 school days in grades 1-6 and 400 in grades 7-12 (200 at K-8 schools), and two years of PE in high school. (California Education Code)
• In 2025, about 4 in 5 US high school students (80.2%) did not have PE on all five school days in an average week. (CDC, 2026)
• Students with daily PE were about twice as likely to meet both the aerobic and the muscle-strengthening guidelines. (Michael, 2023)
COACHED STRENGTH TRAINING
• A chosen, focused activity, built on what expert groups call for: qualified coaching, technique before load, and gradual progression. (Lloyd, 2014; NSCA, 2009; AAP, 2020)
• Expert groups also call for programs matched to each young person's skill, training age and maturity. (Lloyd, 2014; AAP, 2020)
• NSCA guidelines suggest no more than 10 junior high or 15 high school athletes per strength coach, with closer supervision for complex lifts such as weightlifting movements. (NSCA, 2017)
• At Fortified Strength, classes generally have one coach for every seven athletes.
Both matter. The American Academy of Pediatrics calls it important to include resistance training in PE classes and in youth sport programs. (AAP, 2020)
EVERY AGE
Strength for Youth, Teens, Adults and Masters
The American Academy of Pediatrics, the NSCA and a 2014 international consensus support well-designed, supervised strength training for young people. (AAP, 2020; Lloyd, 2014; NSCA, 2009) The World Health Organization recommends regular muscle-strengthening activity for all age groups. (WHO, 2020)
YOUTH 6-12
• Supervised resistance training can build strength in young people, including before puberty. Evidence in girls is thinner. (Behringer, 2010)
• Guidelines call for muscle- and bone-strengthening activity at least 3 days a week. (US Guidelines, 2018)
• Age 6 is within the range experts discuss for bodyweight and technique work. Readiness matters more than age. (AAP, 2020; ASCA, 2017)
TEENS 13-17
• Strength training can improve jumping and sprinting in young athletes. These gains are smaller than the gains in strength. (Lesinski, 2016)
• Research has not shown that well-designed, supervised strength training harms growth. (AAP, 2020; Malina, 2006)
• Reported injury rates in well-supervised youth programs are low. (Malina, 2006; Faigenbaum, 2010)
ADULTS 18+
• Guidelines call for muscle-strengthening activities that work all major muscle groups on 2 or more days a week. (WHO, 2020)
• In trials, strength training improved middle- and long-distance performance across running, cycling, skiing and swimming. (Berryman, 2018)
• Do both: meeting the strength and aerobic guidelines together is linked to the lowest risk of early death. (Zhao, 2020)
MASTERS AND OLDER ADULTS
• The WHO recommends varied activity that emphasizes balance and strength training on 3 or more days a week for older adults, "to enhance functional capacity and to prevent falls." (WHO, 2020)
• ACSM and NSCA statements support resistance training for healthy adults, including older adults. Start gradually, with coaching. (ACSM, 2026; NSCA, 2019)
Myth and Fact
MYTH
Strength training stunts growth.
FACT
Research has not shown that well-designed, supervised strength training harms growth. (AAP, 2020; Malina, 2006)
MYTH
Strength training is only for athletes who compete.
FACT
The World Health Organization recommends regular muscle-strengthening activity for all age groups. (WHO, 2020)
MYTH
It's too late to start.
FACT
Strength can be built at every age studied, including people in their 90s. Start gradually, with coaching. (Liu, 2009; NSCA, 2019)
Strength Starts With One Class
No experience necessary, and competing is optional. Find a class for your age and your goal. Cost should never keep an athlete from training. Ask about tuition assistance.
Sources
This page shares research for general information. It is not medical advice. If you have a health condition, are pregnant, or are recovering from an injury or surgery, talk to your doctor before starting a new exercise program.
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California Education Code, sections 51210, 51222 and 51225.3, on PE minutes and the high school requirement.
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