Running back or run it back?

NFL teams continue to give big extensions to star running backs despite a history of returns on investment that mostly warrant a do-over wish.

The Giants likely will follow suit next offseason when Saquon Barkley first becomes eligible for a new contract, showing faith he is an Adrian Peterson-like exception to the rule. Here’s a look at some of the big deals that were done — or not done — in recent years:

SIGNED AN EXTENSION

Derrick Henry, Titans

Contract: 4 years, $50 million, including $25.5 million guaranteed

Signed: July 16, entering age-26 season

Extension with two fully guaranteed years replaced a temporary franchise tag for NFL’s leader in rushing attempts, yards and touchdowns in 2019.

Christian McCaffrey, Panthers

Contract: 4 years, $64 million, including $38.1 million guaranteed

Signed: April 13, entering age-24 season

Third player in NFL history with 1,000 yards rushing and 1,000 receiving in the same season was also the first 2017 draft pick to cash in — despite changes at general manager and head coach.

Ezekiel Elliott, Cowboys

Contract: 6 years, $90 million, including $50 million guaranteed

Signed: Sept. 3, 2019, entering age-24 season

Held out until four days before the 2019 season opener, jumping Amari Cooper and Dak Prescott in the extension line. Numbers slipped just a tick in 2019 but he still was a top-five back.

David Johnson, Cardinals

Contract: 3 years, $39 million, including $31.8 million guaranteed

Signed: Sept. 8, 2018, entering age-27 season

Risky move paying for 2016 production backfired. Dislocated wrist in 2017 season opener was precursor of injury problems, prompting trade to Texans.

Todd Gurley, Rams

Contract: 4 years, $57 million, including $45 million guaranteed

Signed: July 24, 2018, entering age-24 season

Cautionary tale was released at a $20.1 million dead cap hit without ever playing a down on his extension. Earned $34.5 million for 2018-19 seasons, about triple what he would have if Rams forced year-to-year deals. Signed by Falcons.

Devonta Freeman, Falcons

Contract: 5 years, $41 million, including $22 million guaranteed

Signed: Aug. 9, 2017, entering age-25 season

Signed after back-to-back 1,500-yard seasons and Pro Bowl selections — production never duplicated. Cut with three years remaining and remains a free agent.

LeSean McCoy, Eagles

Contract: 5 years, $45 million, including $20.7 million guaranteed

Signed: May 17, 2012, entering age-24 season

Rare back who got a second big pay day after he was strangely cut in 2014. Signed for five years and $40 million, including $18.2 guaranteed at signing, by Bills.

Adrian Peterson, Vikings

Contract: 6 years, $86 million, including $36 million guaranteed

Signed: Sept. 10, 2011, entering age-26 season

Only non-quarterback to win NFL MVP (2012) in the last 13 seasons. Played five seasons on the extension before Vikings turned down an $18 million team option in 2017, leading him to Saints and Redskins.

Chris Johnson, Titans

Contract: 4 years, $53.9 million, including $30 million guaranteed ($13 million at signing)

Signed: Sept. 1, 2011, entering age-26 season

Only Peterson had more rushing yards from 2008-13. Titans couldn’t trade Johnson after a career-low 3.9 yards per carry in 2013, so they cut him with three years remaining.

DID NOT SIGN AN EXTENSION

Le’Veon Bell, Steelers

Played on the franchise tag ($12.1 million) for the Steelers in 2017, then sat out rather than doing it again in 2018. Signed a four-year, $52.5 million free-agent contract with Jets, but had his least productive full season in 2019.

Melvin Gordon, Chargers

Misplayed his hand by turning down an extension worth $10 million per year and ultimately played 2019 on the franchise tag, after a four-game holdout. Settled for less from Broncos in free agency.