8-K

UNITED STATESSECURITIES AND EXCHANGE COMMISSIONWASHINGTON, D.C. 20549

FORM 8-K

CURRENT REPORT

Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934

INTERACTIVE STRENGTH INC.

(Exact name of Registrant as Specified in Its Charter)

(Former Name or Former Address, if Changed Since Last Report)

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions:

☐Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425)

☐Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12)

☐Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b))

☐Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

Securities registered pursuant to Section 12(b) of the Act:

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§ 230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§ 240.12b-2 of this chapter).

Emerging growth company ☒

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ☐

Item 8.01 Other Events.

On March 6, 2026, Interactive Strength Inc. (the “Company”) increased the maximum aggregate offering price of the shares (the “Shares”) of the Company’s common stock, par value $0.0001 per share (the “Common Stock”) issuable under the At The Market Offering Agreement (the “Sales Agreement”) with H.C. Wainwright & Co. LLC, dated May 17, 2024 to $6,057,000 and filed a prospectus supplement dated March 6, 2026 (the “Prospectus Supplement”) under the Sales Agreement for an aggregate of $6,057,000. Prior to the date hereof, the Company sold shares of common stock having an aggregate sales price of approximately $1,673,180 pursuant to General Instruction I.B.6 of Form S-3 under the Sales Agreement in the last 12 calendar months and approximately $12,130,000 under the Sales Agreement in the aggregate. A copy of the legal opinion as to the legality of the $6,057,000 of shares of Common Stock issuable under the Sales Agreement and covered by the Prospectus Supplement is filed as Exhibit 5.1 attached hereto.

The Shares will be issued pursuant to our shelf registration statement on Form S-3 (File No. 333-288405) filed by the Company with the SEC on June 27, 2025 and declared effective by the SEC on September 22, 2025 and the prospectus supplement filed on January 23, 2026 as amended and supplemented by the Prospectus Supplement.

Item 9.01. Financial Statements and Exhibits.

(d) Exhibits

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.

EX-5.1

Exhibit 5.1

March 6, 2026

Interactive Strength Inc.

1005 Congress Avenue, Suite 925

Austin, TX 78701

Ladies and Gentlemen:

We have acted as counsel to Interactive Strength Inc., a Delaware corporation (the “Company”), in connection with the above-referenced registration statement (the “Registration Statement”), the prospectus supplement dated January 23, 2026 (the “Prior Prospectus”), and the prospectus supplement dated March 6, 2026 (the “Prospectus Supplement”), relating to the offering and sale by the Company of shares (the “Shares”) of common stock of the Company, par value $0.0001 per share (the “Common Stock”), having an aggregate offering price of up to $6,057,000, pursuant to that certain At The Market Offering Agreement (the “Sales Agreement”) dated May 17, 2024, between the Company and H.C. Wainwright & Co., LLC. The Shares are covered by the Registration Statement and we understand that the Shares are to be offered and sold in the manner described in the Prior Prospectus as amended and supplemented by the Prospectus Supplement. This opinion is being delivered at the request of the Company and in accordance with the requirements of Item 601(b)(5) of Regulation S-K promulgated by the Commission.

For purposes of this opinion, we have examined such documents and reviewed such questions of law as we have considered necessary and appropriate for the purposes of our opinion set forth below. In rendering our opinion, we have assumed the authenticity of all documents submitted to us as originals, the genuineness of all signatures and the conformity to authentic originals of all documents submitted to us as copies. We have also assumed the legal capacity for all purposes relevant hereto of all natural persons and, with respect to all parties to agreements or instruments relevant hereto other than the Company, that such parties had the requisite power and authority (corporate or otherwise) to execute, deliver and perform such agreements or instruments, that such agreements or instruments have been duly authorized by all requisite action (corporate or otherwise), executed and delivered by such parties and that such agreements or instruments are the valid, binding and enforceable obligations of such parties. As to questions of fact material to our opinions, we have relied upon certificates of officers of the Company and of public officials.

Based upon and subject to the foregoing, we are of the opinion that the Shares have been duly authorized and, when issued and sold by the Company and delivered by the Company against receipt of the purchase price therefor, in the manner contemplated by the Prior Prospectus and the Prospectus Supplement and the Sales Agreement, will be validly issued, fully paid and non-assessable. The opinions expressed herein are limited to the laws of the General Corporation Law of the State of Delaware and the laws of the State of New York, as currently in effect, and no opinion is expressed with respect to any other laws or any effect that such other laws may have on the opinions expressed herein.

We consent to the filing of this opinion with the SEC as Exhibit 5.1 to the Company’s Current Report on Form 8-K filed on March 6, 2026, which is incorporated by reference in the Prospectus Supplement. We also consent to the reference of our firm under the caption “Legal Matters” in the Prospectus Supplement and in each case in any amendment or supplement thereto. In giving this consent, we do not thereby admit that we are in the category of persons whose consent is required under Section 7 of the Securities Act of 1933, as amended, or the rules and regulations of the Securities and Exchange Commission promulgated thereunder.