Table 1 Characteristics of the evaluated 10 trials investigating exercise effects on bone strength^a

Children and Adolescents

Macdonald et al. [19]

EX: N = 281, CON: N = 129

Age: 10.2 (0.6), boys and girls

Duration: 16 months

EX: 1 step: 15 min of physical activity (PA) 5 times per week

2 step: 5-36 jumps per day 4 times per week

CON: Two 40-min physical education (PE) classes per week

Distal tibia

Tibial midshaft

pQCT

Macdonald et al. [20]

EX: N = 293, CON: N = 117,

Age: 10.2 (0.6), boys and girls

Duration: 16 months

EX: 1 step: 15 min of PA 5 times per week

2 step: 5-36 jumps per day 4 times per week

CON: Two 40-min PE classes per week

Hip

DXA-derived

hip structural analysis

MacKelvie et al. [21]

EX: N = 31, CON: N = 33,

Age: 10.2 (0.5), boys

Duration: 24 months

EX: 10-12 min of high-impact PA 3 times per week

CON: 10-min stretch during PE class and a stretch break during class

Hip

DXA-derived

hip structural analysis

Petit et al. [22]

EX: N = 87, CON: N = 90,

Age: 10.1-10.5 (0.5), girls

Duration: 7 months

EX: 10-12 min of high-impact PA 3 times per week

CON: 10-min stretch during PE class and stretch break during class

Hip

DXA-derived

hip structural analysis

Weeks et al. [23]

EX: N = 52, CON: N = 47

Age: 13.8 (0.4), boys and girls

Duration: 8 months

EX: 10-min high-impact PA 2 times per week

CON: Warmup and stretching exercises during PE classes 2 times per week

Hip

DXA-derived estimation of cross-

sectional moment of inertia (CSMI)

Adults

Vainionpaa et al. [24]

EX: N = 39, CON: N = 41,

Age: 38 (2), women

Duration: 12 months

EX: 60-min workout classes including steps and hops 3 times per week and 10-min daily steps and hops

CON: Normal daily activity

Proximal tibia

Midfemur

DXA-derived estimation of cross-sectional moment of inertia (CSMI)

Older Adults

Cheng et al. [13]

EX: N = 20, CON: N = 20,

Age: 50-57, women

Duration: 12 months

EX: Supervised high-impact circuit training session 2 times per week

and similar home exercises 4 times per week

CON: Normal daily activity

Tibial midshaft, Proximal tibia

Midfemur, Proximal femur

QCT-derived maximum

moment of inertia (I max)

Karinkanta et al. [15]

EX: N = 112, CON: N = 37,

Age: 73 (2)

Duration: 12 months

EX: Resistance, balance jumping, and their combination group 3 times per week, including at least 50%-60% of repetition maximum (RM) and jumps

CON: Normal daily activity

Distal tibia, tibial shaft

Femoral neck

DXA-derived hip structural analysis

pQCT derived bone strength index (BSI)

Liu-Ambrose et al. [53]

EX: N = 66, CON: N = 32

Age: 79 (3)

Duration: 6 months

EX: Resistance and agility training group 2 times per week

including at least 50%-60% of RM and ball games, dance movements

CON: stretching

Distal tibia, Tibial shaft

pQCT-derived polar stress

strain index (SSI)

Uusi-Rasi et al. [14]

EX: N = 41, CON: N = 41,

Age: 53 (2)

Duration: 12 months

EX: 20-min multidirectional jumps and steps 3 times per week

CON: Normal daily activity

Distal tibia, tibial shaft

Femoral neck

DXA-derived bone strength index (BSI)

pQCT-derived bone strength index (BSI)