LIST OF ILLUSTRATIONS Figure No. PART I Page a co 10. 55 12. 13. 14. VARSITY ATHLETIC GROUP SERIES Three Fatigue Curves of One Individual One Individual’s Curve of Improvement for Thirteen Weeks 20 . Three Average Fatigue Curves of the Same Athletic Group One Curve of Improvement of the Group for POGLUHCH WORE Iw EO i ace ge ter Ped eN ea ees hs 20 PART II JUNIOR HIGH SCHOOL SERIES . Measured Efforts in Fatigue Curves of First and Fifth Tests 24 . Costs in Heartbeats in Curves of aie te FOr Nes te ee Ne i Seas 24 ENGINEERS SERIES . Composite Curve of Improvement Over @ Period ot Tien Weeks, oo is oid as GA RU heey 28 . Declining Composite Curve of Costs in Heartbeats Oreck aPerwd of Ten Weeks 238 eS eA a: 28 . The Composite Fatigue Curve of Engineers for Ten Weeks .29 . The Composite Curve of Condition for Ten Weeks........ 29 - Composite Fatigue Curves of First and Fourth Days Showing Increasing Production. ....................005 30 Composite Curves of Condition and Costs in Heartbeats For the Production of the First and Fourth Days.......... 30 SERIES OF OLDER INDIVIDUAL ‘Twenty-first and Seventy-fifth Fatigue Curves............. $2 ‘Twenty-first and Seventy-fifth Curves of Condition........ 32 AIRCREW SERIES—LEGS Composite Fatigue Curves Improving for 1 St CROONER Pes eres cs Fe TEE OE 34 Four Composite Curves of Condition with SUDA IME NE PPO VMIMEE oocat, OVEP has cos as new eet 34 1]