HEAVY LIFTING WITH THIN BONES: WHAT THE LIFTMOR TRIALS MEASURED

High-intensity resistance and impact training has generally not been recommended for people with osteopenia or osteoporosis, on the reasoning that heavy load and impact carry fracture risk in a fragile skeleton. Two supervised trials out of Griffith University in Australia set out to measure what actually happens when you apply it to that population anyway. Here is what they found.

What the Trials Were Testing

Bone tissue responds to mechanical strain, and the research on osteogenic loading points to the magnitude and the rate of strain as the drivers rather than duration. That is the physiological reasoning behind high-intensity resistance and impact training — HiRIT in the literature — which deliberately supplies both. The open question the two trials below were designed around was whether that stimulus could be delivered to people who had already lost bone without producing injury.

LIFTMOR: 101 Postmenopausal Women, Eight Months

Watson and colleagues published the LIFTMOR trial in the Journal of Bone and Mineral Research in February 2018 (33(2):211–220). They recruited 101 postmenopausal women with low bone mass — a T-score below −1.0, screened to exclude conditions and medications known to affect bone and physical function — with a mean age of 65 ± 5 years. Participants were randomized to eight months of twice-weekly, 30-minute supervised HiRIT (n = 49) or a home-based low-intensity exercise program as control (n = 52).

The HiRIT sessions used five sets of five repetitions at greater than 85 percent of one-repetition maximum across deadlift, overhead press, and back squat, plus impact loading via jumping chin-ups with drop landings. The first month used bodyweight and low-load variants while participants learned the movement patterns.

Reported results, HiRIT versus control, as percentage change:

• Lumbar spine BMD: +2.9 ± 2.8% versus −1.2 ± 2.8% (p < 0.001)
• Femoral neck BMD: +0.3 ± 2.6% versus −1.9 ± 2.6% (p = 0.004)
• Femoral neck cortical thickness: +13.6 ± 16.6% versus +6.3 ± 16.6% (p = 0.014)
• Height: +0.2 ± 0.5 cm versus −0.2 ± 0.5 cm (p = 0.004)
• All functional performance measures — timed up-and-go, functional reach, five-times sit-to-stand, back and leg strength: p < 0.001

On the safety question the trial was built around, compliance was 92 ± 11 percent in the HiRIT group and the trial reported one adverse event across the eight months: a minor lower back spasm, costing 2 of 70 training sessions.

The authors' own summary of that result:

Contrary to current opinion, HiRIT was efficacious and induced no adverse events under highly supervised conditions for our sample of otherwise healthy postmenopausal women with low to very low bone mass.

LIFTMOR-M: 93 Men, Same Design

Harding and colleagues ran the male counterpart, with primary outcomes published in the same journal in August 2020 (35(8):1404–1414). Ninety-three generally healthy men aged 45 and over with low hip and/or lumbar spine BMD — mean age 67.1 ± 7.5 years, femoral neck T-score −1.6 ± 0.6 — were assigned to eight months of twice-weekly HiRIT (n = 34) or machine-based isometric axial compression training (n = 33), compared against a matched group of 26 men continuing usual activities.

HiRIT versus control:

• Lumbar spine BMD: +4.1 ± 0.7% versus +0.9 ± 0.8% (p = .003)
• Trochanteric BMD: +2.8 ± 0.8% versus −0.1 ± 0.9% (p = .024)
• Calcaneal broadband ultrasound attenuation: +2.2 ± 0.7% versus −0.8 ± 0.9% (p = .009)
• Stiffness index: +1.6 ± 0.9% versus −2.0 ± 1.1% (p = .011)
• Lean mass: +1.5 ± 0.8% versus −2.4 ± 0.9% (p = .002)
• Timed up-and-go, five-times sit-to-stand, back extensor and leg extensor strength: all p < .05

Five minor adverse events were reported across both exercise groups — two in HiRIT, three in the isometric group.

The Comparison Between the Two Exercise Modes

The male trial's isometric arm is what makes it informative beyond the control comparison, because both arms were loaded and supervised.

Machine-based isometric axial compression improved lean mass (+0.8 ± 0.8% versus −2.4 ± 0.9%, p = .013) and five-times sit-to-stand relative to control. Compared head to head, HiRIT showed greater change than the isometric arm on lumbar spine BMD (+4.1 versus +2.0 percent, p = .039), stiffness index (p = .025), and five-times sit-to-stand (−10.7 versus −4.5 percent, p = .010). Compliance was statistically indistinguishable between the two — 77.8 ± 16.6 percent versus 78.5 ± 14.8 percent, p = .872.

The Secondary Analyses

A companion analysis in Bone (2020;136:115362) measured bone geometry and strength at the hip, tibia, and radius. HiRIT showed greater medial femoral neck cortical thickness change than control (+5.6 ± 1.7% versus −0.1 ± 1.9%, p = 0.028) and than isometric training (p = 0.044). Both exercise programs maintained bone strength at the distal tibia and distal radius while the control group declined — distal radius total bone strength index measured +1.4 ± 1.4% in HiRIT against −6.0 ± 1.6% in control (p = 0.001). At the proximal radius, HiRIT showed a reduction in cortical area relative to control (−3.1 ± 1.0% versus +1.1 ± 1.2%, p = 0.011). No between-group differences were detected at the diaphyseal tibia.

A further analysis in Osteoporosis International (2021;32(3):451–465) examined thoracic kyphosis and vertebral morphology. HiRIT showed improved Cobb angle from baseline (−3.5 ± 1.5°, p = 0.027) and reduced "standing tall" kyphosis relative to control (−2.3 ± 0.6° versus +1.4 ± 0.7°, p < 0.05). Over the eight months, no incident vertebral fractures or progression of existing vertebral fractures were recorded in the HiRIT group; five incident thoracic vertebral fractures and one wedge-fracture progression were recorded in the isometric group. The authors described this analysis as exploratory, drawn from 40 participants in the per-protocol sample, and called for larger trials to confirm it.

What These Trials Did and Did Not Measure

Four features of how the research was built determine what the numbers above can be applied to. None of them are hidden — all four are stated by the authors in the papers themselves.

Every session was supervised. Both trials ran under direct supervision by the research team, with a first month of graded low-load onboarding. The LIFTMOR authors attach that condition explicitly to their own conclusion — "under highly supervised conditions" is their wording, not a qualifier added here. What the trials tested was supervised high-intensity training. Unsupervised training was not tested.

Fracture rates were not the endpoint. The measured outcomes were bone mineral density, bone geometry, and physical function — which the literature treats as risk factors for fracture. The trials were not designed or powered to measure whether fewer bones break, and the authors do not report that they were.

The male trial's control group was not randomized. LIFTMOR-M is described by its own authors as semi-randomized: participants were randomized between the two exercise arms, but the 26-man control group self-selected into usual activities and was matched rather than randomly assigned. The women's trial, LIFTMOR, was fully randomized.

Both ran eight months in screened populations. Participants were generally healthy and excluded for conditions and medications known to affect bone health. Eight months is the full duration of the evidence — what happens over three years, or in someone taking osteoporosis medication, was not measured here. And the percentage changes are small in absolute terms; a 4.1 percent lumbar spine change is a meaningful figure for a bone intervention and still a small number.

What the Studied Protocol Looked Like

For reference, this is what participants in these trials actually did — a description of the studied intervention, not a program recommendation:

• Twice weekly, 30 minutes per session, for eight months.
• Five sets of five repetitions above 85 percent of one-repetition maximum, on deadlift, overhead press, and back squat.
• An impact component — jumping chin-ups with drop landings.
• A first month of bodyweight and low-load variants before the high-intensity loading began, so movement patterns were established first.
• Every session directly supervised by the research team. Both trials' safety records describe supervised training, and the authors attach that condition to their conclusions.
• Participants were screened — generally healthy, and excluded for conditions and medications known to affect bone health.

The Bottom Line

Across two supervised eight-month trials in adults who had already lost bone, the groups doing heavy compound lifting with impact loading showed increases in lumbar spine bone density, femoral neck cortical thickness, lean mass, posture measures, and functional performance, while the control groups declined on most of the same measures. The trials measured bone density, geometry, and physical function — which are risk factors for fracture — rather than fracture rates themselves.

That is the evidence as published, including the parts of it that are limited. Whether any of it applies to your skeleton is a conversation for your physician, and if it does, supervision and a graded start were part of what the trials actually tested.

Osteopenia and osteoporosis are medical diagnoses. Any decision about training under either belongs with your physician and a qualified coach.